Concealed overhead door closer

Sept. 22, 1964

3,149,366

P. W. MARTIN

CONCEALED OVERHEAD DOOR CLOSER

Filed Oct. 18, 1960 3 Sheets-Sheet 1

<img file="US3149366A_D0001.tif" />

Sept. 22, 1964

3,149,366

P. W. MARTIN

CONCEALED OVERHEAD DOOR CLOSER

Filed Oct. 18, 1960

Sheets-Sheet 2

<img file="US3149366A_D0002.tif" />

Sept. 22,

1964

3,149,366

P. W. MARTIN

CONCEALED OVERHEAD DOOR CLOSER

Filed Oct. 18, 1960

Sheets-Sheet 3

<img file="US3149366A_D0003.tif" />

United States Patent Office

3,149,366

Patented Sept. 22, 1964

3,149,366

CONCEALED OVERHEAD DOOR CLOSER Paul W. Martin, Des Plames, III., assignor to Republic Industries, Inc., Chicago, HL, a corporation of Hinois

Filed Oct. 18,1969, Ser. No. 63,350 7 Claims. (CI. 16—51)

The present invention relates to concealed door closers, frequently called door checks or checking door hinges. More particularly, it relates to a device of this character 10 which is intended for overhead installation in the metal door frame head jamb, or header tube.

The principal object of the present invention is to provide a novel door closing and checking device which is adapted for overhead installation so as not to require the 15 use of a cement case or other provision for mounting the door checking mechanism in the floor beneath the door.

An additional object is to provide a device of the above character which is double acting, which is fully adjustable, which is extremely rugged and reliable, and which can be manufactured at relatively low cost.

Another object is to provide a novel door checking device of the character set out above, which is easy of installation, and which, if desired, may be installed in the door frame overhead rail by the manufacturer before the door frame is delivered to the installation site.

An additional object is to provide a door checking device, the presence of which is not apparent upon inspection of the door, and which requires no alteration of the floor beneath the door to provide for its installation.

Yet another object is to provide a novel door checking device of the above character which makes full use of modern manufacturing techniques, thereby reducing the manufacturing cost.

Other objects and advantages will become apparent from the following description of a preferred embodiment of my invention which is illustrated in the accompanying drawings.

In the drawings, in which similar characters of reference refer to similar parts throughout the several views:

FIG. 1 is a side view of the upper portion of a door and the adjoining door frame structure shown with portions thereof broken away so as to reveal the general installational features of the door check of the present invention;

FIG. 2 is a top view of the door check shown in installed position with portions of the door frame structure broken away;

FIG. 3 is a longitudinal medial vertical sectional view through a door check embodying the features of the present invention;

FIG. 4 is a horizontal partial sectional view which may be considered as taken in the direction of the arrows substantially along the line 4—4 of FIG. 3. In this view only the checking portion of the mechanism is shown;

FIG. 5 is a partial horizontal sectional view which may be considered as taken in the direction of the arrows substantially along the line 5—5 of FIG. 3. In this view only the closing portion of the mechanism is illustrated;

FIG. 6 is a side view of the device with fractions of the side wall broken away so as to reveal the closing portion of the mechanism in greater detail. In this view, structure which might be confusing has been omitted;

FIG. 7 is a transverse sectional view which may be considered as taken in the direction of the arrows substantially along the line 7—7 of FIG. 5;

FIG. 8 is a transverse fractional sectional view which may be considered as taken in the direction of the arrows substantially along the line 8—8 of FIG. 5;

FIG. 9 is a transverse fractional sectional view which may be considered as taken in the direction of the arrows substantially along the line 9—9 of FIG. 5;

FIG. 10 is a transverse fractional sectional view which 5 may be considered as taken in the direction of the arrows substantially along the line 10—10 of FIG. 4;

FIG. 11 is a transverse fractional sectional view which may be considered as taken in the direction of the arrows substantially along the line 11—11 of FIG. 4;

FIG. 12 is a transverse fractional sectional view which may be considered as taken in the direction of the arrows substantially along the line 12—-12 of FIG. 5;

FIG. 13 is a fractional sectional view which may be considered as taken substantially along the line 13—13 of FIG. 3; and

FIG. 14 is a fractional sectional view which may be considered as taken in the direction of the arrows substantially along the line 14—14 of FIG. 5.

A common checking door closing mechanism of the concealed type requires that a box—usually referred to as a cement case—be installed in the floor beneath the door near the hinged edge thereof, the door checking mechanism subsequently being located within this box or case. The door checking mechanism, when installed, has an up25 standing spindle upon which the door is mounted. The spindle turns with the door and acts as the door bottom pivot.

Although door checking devices of this character have been highly successful and are in wide usage, they have 30 several serious disadvantages associated with their location. Probably the principal of these is that proper installation of the cement case in the floor prior to the installation of the door closer is an extremely expensive operation, event when done in new buildings at the time ³³ the floor is layed. The door closer of the present invention eliminates this cost completely, since no elements at all need to be installed in the floor. What simple installation is required can be performed by the manufacturer of the door frame before the assembly leaves the factory. Or if desired, partial installation or adaptability can be accomplished by the door frame manufacturer.

Although there have been prior attempts to provide overhead door closers of the concealed type, it is my experience that such closers have been largely unsatisfactory. This is principally because the space limitations imposed by the header tube of the door frame are so extremely severe that it was not possible with prior arrangements ₅θ to get the necessary mechanism into the space available. This resulted in the use of unsatisfactorily small and fragile components, and to the omission of features generally considered necessary, or at least advisable, in such devices.

As an example of the nature of the problem, the door closer of the present invention is completely housed within a standard door frame header tube, such standard tube having an interior width of 414 and a thickness from top to bottom of W. To fit this space, the door closer _6Q of the present invention has a top to bottom dimension (excluding the spindle extension which projects downwardly to connect with the door) of PA, and an overall width dimension of 4%_e. Total length of the door closer, although this dimension is not so critical, is apθ5 proximately 15%. As will appear presently, the door closer of this invention does not sacrifice any of the features ordinarily considered as of value.

In the drawings, I have illustrated a swinging door at 20 having an upper channel 22 which contains an arm 24 secured to the door. This arm may be of any suitable type and is rigidly attached to the squared end of a vertical spindle 26 which extends upwardly into the door

3,149,366 ³ closer housing, indicated generally at 28. This door closer mechanism is located within the door frame header tube 30, the interior space of which, indicated at 32, is rectangular in section and has the dimensions previously given. Exteriorly, the tube is 1% thick by 416 wide. At one end, the header tube is secured to the vertical jamb 34, which also comprises a rectangular metal tube having the same dimensions as the header tube. Since the vertical jambs are identical, only the one at the hinge side is shown.

The door frame structure just described has been quite standard for several years and, for installation of the door closer, is altered only by drilling or punching a few holes and by providing an opening in the lower surface of the header tube through which the door closer mechanism can be inserted. This opening is subsequently closed by a dress plate 36 which is secured directly to the bottom surface of the closer mechanism as will appear.

Although most standard door frames have the dimensions and structure described above, there are some light weight doors which have frames with somewhat smaller dimensions from front to back than those given. To accommodate the present door closer mechanism to frames of this character, the usual expedient used by me is to provide the header tube With a wider section near the hinge end so that the mounting of the checking mechanism is essentially the same. This wider section may be welded with suitable faired sections into the main portion of the tube without producing noticeable distortion in the door frame appearance. It will be appreciated that this frame alteration, ordinarily to be accomplished by the frame maker, forms no part of the present invention. It is given here simply for the purpose of suggesting one arrangement for accommodating the door closer of the present invention to frames of substandard dimensions.

From the drawings it will be seen that the door closer housing is generally rectangular, although at its pivot end the case is rounded as at 38, excepting for the projecting mounting ears 39, whereas at the opposite end, 40, it is more nearly rectangular. At this end also mounting tabs or ears 41 are provided. The housing is comprised of a lower or tray portion 42 which has its upper opening closed by a cover plate 44. Both of these members are formed as die castings which are well ribbed and provided with mounting pads and other utilitarian elements in a well known manner as will be described. In the closed assembled condition, the tray portion 42 is secured to the cover 44 with an intervening gasket 46 by means of closely spaced peripheral screws 66. The assembly is secured in place by cap screws 48 which pass through openings in the rearward ears 41 and are threaded into a mounting bracket 50 which, as shown, is secured to the upper surface of the header tube by rivets 52. At the opposite end, cap screws 48 similarly pass through the ears 39 and secure the door check housing to a bracket 54. This bracket is attached to the header tube by means of screws 56 and to the vertical jamb by means of the bolts 58 threaded through nuts 60.

The arrangement is such, therefore, that the simple brackets 54 and 50, or equivalent structure, can, if desired, be installed by the manufacturer of the door frame. The door check can then be installed simply by being located on the job and secured by inserting and tightening the cap screws 48. Optionally, the frame manufacturer can supply the frame with the check mechanism in place. Once installed, the door closing mechanism is completely out of sight excepting that the spindle 26 extends downward below the bottom surface of the header tube, as does a portion of the hub 62 through which the spindle passes, this hub being formed as a portion of the lower housing element 42. After installation, the opening in the lower surface of the header tube is closed by the previously mentioned dress plate 36 which is secured by means of screws 64 threaded into the lower surface of the housing member 42. The above description of the general over- all character of the door closer and its mounting has been given in detail, since these features will be important to those who make use of the device.

This specific door closer, in spite of the severe space limitations, has the following typical operating characteristics which are obtained by the mechanism to be described presently. The door swings open freely and has a cushion stop. It is double acting and is easily adaptable for either 90° or 105° swing, with or without a holdopen feature. The closing power within the important last 20 degrees of swing, depending upon the closing springs used, may be from 15 foot pounds to 44 foot pounds, and is adjustable. Depending upon the lower pivot used, the door closer is adaptable for the operation of doors having weights of up to 600 pounds. The checking action permits a fast return swing of the door until the door nears the closed position, at which time the closing speed becomes slower. The fast and slow closing speeds are adjustable independently. Maximum checking force is 166 foot pounds, above which value a safety valve opens to prevent the device being subjected to abnormal stresses.

As is highly desirable, the closing force is less during the major portion of the swing than it is during the last 20 degrees of closing movement. This promotes easier operation of the door and yet permits tight sealing against wind loadings or air pressure differentials which may have a tendency to blow the door open somewhat. It will, of course, be appreciated that minor alterations may be made for changing the performance data given, this data relating to the specific example to be described. It is believed, however, that these performance characteristics will provide maximum utility in a device of this character and have no precedent in a door closer of such small size.

The spindle 26 is seen as extending upwardly near one end of the assembly through a ball bearing and oil seal 68 provided in the bottom of tray portion 42. The upper end of the spindle is enlarged and has a recess which receives a needle bearing 70 carried internally upon a pin 72 which is riveted to the cover plate 44. This arrangement saves considerable internal space between the bottom of the tray portion 42 and the cover plate 44 for the placement of checking and closing cams which can be mounted externally upon the spindle without interference from the more conventional type external upper bearing mounting. The spindle 26 is preferably forged, and near the bottom of the case internally is fitted to a cam disc 74 against the edge of which the springs operate to swing the door toward closed position. This cam is welded to a shoulder 75 upon the spindle as at 76, and therefore becomes an integral spindle element.

At its upper end, a separate disc cam 78 is fitted to the spindle and is retained in place thereon against a shoulder 80. This cam is loose so that it can rotate relative to the spindle, but its movement is limited by a pin 82 which is press fitted into the cam 74 from above at an off-center position toward the case end 38. The upper end of this pin extends into a slot 84 between a pair of ears 86 of the cam 78 so that the cam 78 can rotate freely relative to the cam 74 until one or the other of the ears 86 engages the pin 82. The width of the slot and the size of the pin 82 and its location are such that the free movement of the cam 78 from side to side is limited to a total of approximately four to five degrees. The reason for this will become apparent presently.

The spindle and cam assembly is completed by a flat thrust washer 88 between the inner end of the hub 62 and the lower cam 74, and a similar washer 90 between the upper surface of the cam 78 and an annular ridge provided upon the inner surface of the cover plate 44. These thrust washers may satisfactorily be formed of phenol formaldehyde resin composition.

The shape of the active portion of the lowermost or closing cam 74 may best be described in terms of its operation and effect within the mechanism. Two cam fol3,149,366

S' lowing rollers 92 bear against this cam in a symmetrical relationship on opposite sides of the spindle 26. As the spindle rotates in one direction or the other, one or the other of the rollers 92 will be urged toward the right so as to compress a pair of door closing springs. The roller and spring mechanism will be described presently.

The cam is of butterfly type (symmetrical about the center line) and on each side it has a relatively sharp rise, as at 96 for instance, against which the roller 92 bears when the door is in closed position. This provides an abutment which urges the rollers 92 toward the right comparatively sharply during the first 20 degrees or so of rotation of the cam shaft 26 away from the at rest position. After about 20 degrees of rotation, the cam follower 92 rolls upon a portion of the surface at 98 having a more gradual rise, so that the torque reaction upon the shaft 26 is less, since the roller 92 moves a linear distance which is less for any particular angularity of rotation of the cam.

Toward the opposite end of the active portion of the cam face 98 there is a small comparatively sharp rise 99 followed by an arcuate depression 108 which can be entered by the roller 92 when the door reaches its farthest open position. The sharp rise 99 acts as a stop which ordinarily prevents the door from being swung open beyond the desired limit. With slight purposeful additional exertion, the door can be swung past this point so that the roller 92 drops into the reentrant portion 100, thereby latching the door in open position. It may, of course, be started in the closing direction by a slight push sufficient to disengage the roller 92 from the depression 100. Thereafter, action of the spring urging the roller 92 toward the left will cause the door to swing toward closed position, and it will be noted that at the conclusion of this swinging movement, that is, during the last 20 degrees or so, the torque produced upon the spindle 26 is considerably increased because of the previously referred to sharp rise portion of the cam surface at 96. In the closed position, if no door stop is used, the door is centered when both rollers 92 bear against the cam 74 in the manner shown in the drawings.

The cam following and spring mechanism is symmetrical, and therefore only one side needs specific description. Each roller 92 is journaled for rotation at the end of a forked member 102, these forked members being joined together by a cross strut 142 (see FIG. 8). Rearwardly of each roller 92, the member has an upwardly offset section 104 having a socket 106 which receives a guide rod 108 connected thereto by means of a cross pin 110. The offset is for the purpose of permitting the roller 92 to follow the cam 74 while at the same time bringing the guide rod 108 more nearly to the middle of the case vertically so as to provide clearance for a coil compression spring 112 through which the rod 108 passes.

At the rearward end of the closing mechanism there is a crosshead 114 which at each side is provided with a passage through which the rearward ends of the rods 168 extend. Near its rearward or right hand end, the passage is provided with a shoulder 113 which acts as a bottom stop for an annular bushing 120 formed of tough wearresistant plastic material such as nylon or Delrin. Delrin is a trademark of E. I. du Pont de Nemours &amp; Company, and is applied by this company to a polymerized formaldehyde substance which has much the same properties as nylon excepting that it is more stable dimensionally and therefore is generally to be preferred in applications like the present. Of course other substances also will suggest themselves as satisfactory for the purpose.

Tn any event, the bushing 120 has a length substantially equal to the depth of the recess ahead of the shoulder 118, and it is retained in place by a washer 122 which surrounds the rod 108 and is urged against the crosshead 114 by the pressure of the spring 112. In order to aid in assembly and to provide a stop in the opening direction as will appear presently, the end of each rod is tapped g

and receives a cap screw 124, the head of which is larger than the diameter' of the rod 108. The head of this screw fits within a recess 126 formed in the rearward side of the crosshead, and when the spring 112 is fully extended, prior to final assembly, the head 124 bears against the bottom of the recess 126 and prevents the subassembly from falling apart.

So as to insure that the cam following roller 92 is properly guided and that the guide rod 108 moves straight rearwardly when compressing the spring 112, the yoke forming member 102 is provided with a second roller 130 in a position behind the roller 92 and spaced outwardly slightly with respect thereto. The outer edge of the roller 130 bears against a hardened steel track forming plate 132 as is best seen in FIG. 7. This track forming element has a groove 134 which closely fits the edge of the roller 130 so that although the roller is free to roll longitudinally of the track, it cannot move transversely.

The face of the track forming plate 132 opposite the track is flat and slides from the top into a flat bottomed depression 136 formed in the die cast body member 42. At its top edge the plate extends outwardly sufficiently so that it is flush, as at 138, with the top edge of the lower case portion 42, and thus, when the cover plate 44 is secured, it holds the track-forming member 132 downwardly and locks it in place. In other words, from top to bottom, the member 132 is wedged between the cover and the bottom of the case, whereas, endwise movement of the track member is prevented by the shoulders at the ends of the depression within which it is located. It is prevented from moving toward the center line of the case by an overyling lip 140 formed as a portion of the die cast cover 44, and also by the near presence of the roller 130. Rotation of the rods 108, which would tend to throw the rollers 92 and 130 out of alignment is, of course, prevented by the strut 142 which unifies the system from side to side as previously mentioned. Twisting of the crosshead 114 is prevented by its lower surface which is flat and clears the fiat bottom of the case only slightly, as is best seen at 141 in FIG. 6. Thus rotation of the cam 74 in either direction will urge the cam following system at both sides straight rearwardly and will compress the springs 112 at both sides of the case.

The crosshead 114 has a threaded passage 144 at its center which embraces an adjusting jackscrew 146 which extends outwardly through the rearward end of the case where its end is squared, as at 148, so that the screw can be turned with a wrench without opening the mechanism. Where the screw passes through the case, leakage is prevented by an oil seal 160, and the opposite or inner end of the shaft is journaled at 152 in a bearing formed through a strut 154 which is a unitary portion of the die cast case member 42. Longitudinal outward movement of the screw is prevented by a snap ring 156 which fits in a groove in the shaft, this snap ring being backed up by a collar 158 and thrust washer 160 which in turn engages the face of a heavy leaf spring 162 (to be described in greater detail presently) which bears against a flat plate 164 which rests against an abutment 166 formed as a portion of the case.

By rotating the squared end 148 of the adjusting jackscrew, the crosshead 114 can be moved toward or away from the cam 74, thus adjusting the pressure exerted by the springs 112, this in turn adjusting the closing torque applied to the door spindle 26.

The leaf spring 162 is formed of spring steel and is quite stiff. At its center it bears against the flat backup plate 164, whereas its ends are curved forwardly as at 168 where they are in a position to intercept the heads of the screws 124 when the guide rods 108 are forcibly urged rearwardly as the door is opened. This acts as a cushion stop for the door, and it should be noted that as the leaf spring 162 is flattened, due to impact at the ends thereof by

3,149,386 the screw heads 124, it will gradually be brought into full contact with the backup plate 164. This expels the hydraulic fluid trapped between the two faces forcibly, and helps with the cushioning action, particularly in providing a variable spring rate which increases markedly just before the spring 162 reaches the limit of its travel. This hydraulic activity also gives the system a deadness, or lack of sharp rebound which is highly desirable.

The ease of assembly of this closing structure should be particularly noted. Essentially it is necessary merely to put the subassembly in place, pass the jackscrew from the outside through the case and the several elements to the right of the crosshead, and screw the jackscrew 146 into the crosshead 114, and snap the ring 156 in place, the cam following assembly together with the guide rods 108 and springs 112 previously having been connected to the crosshead 114 and lowered into place along with the two track-forming members 132. As mentioned above, the screws 124 prevent this subassembly from falling apart prior to final assembly.

The checking mechanism is located along the center line of the case and is actuated by the previously mentioned cam 78 which engages the cam following roller 170. The active portion of the cam 78, which is symmetrical, is in general the reverse of the contour of the cam 74 in that the roller 170 is urged farthest toward the right when the door is in closed position, and is permitted to move toward the left as the door opens. This movement is substantially uniform for any particular angularity of swing of the door.

In FIG. 4 the cam 78 is shown in its theoretical centered position for purpose of illustration only, since the cam never actually takes quite this position when the door is closed. In this position the roller 170 is shown as bearing against the sharp nose 172 of the cam, under which conditions no checking action would take place, since no linear movement of the roller 170 would occur upon slight angular movement of the cam 78. In other words, the door would approach closed or latching position under restraint of the checking mechanism until almost closed, at which point there would be a sharp closing movement that would result in noise and generally unsatisfactory operation.

Because of the four to five degrees of movement of the cam 78 about the spindle 26, the cam 78 will always take a position with the nose 172 at one side or the other of the center line of the roller 170, depending upon the last direction of movement of the door. For instance, starting from the position shown in FIG. 4 if the spindle 72 is rotated in a counterclockwise direction along with opening movement of the door, the pin 82 will strike the inner surface of the ear 86 which is shown in a position below the pin, thereby causing the cam 78 to rotate in a counterclockwise direction slightly. Pressure of the roller will then swing the cam so that the upper ear is against the pin 82 and this relationship is maintained so that when the door returns to the completely closed condition, the nose 172 of the cam 78 will be slightly above the center line of the roller 170. If the door is then swung open in the opposite or clockwise direction, the pin 82 operating against the upper ear 86 will snap the nose of the cam 172 over the roller 170, after which the cam swings slightly so that its lower ear 86 is against the pin 82. Thereafter the action continues as previously described, excepting that when the door returns to closed position the pin 82 will remain in engagement with the lower ear 86, thereby permitting the cam 78 to come to rest with, the nose 172 slightly below the center line of the roller 170. This arrangement always insures that checking action will occur throughout the closing movement of the door until the door is brought to fully closed or latched position regardless of the direction of door swing.

The combined bracket for the roller 170 and push rod its made up of four layers of ^J/a laminated cold rolled steel, the actual pieces used in the present embodiment of the invention being either % or % wide. The reason that this particular material is used is that much close machining is avoided, since cold rolled steel stock of these nominal dimensions is held to sufficiently close tolerances to be used as is. For instance, on % stock, the tolerance on the width is .003 whereas on % stock it is .002. On the % nominal thickness, the tolerance is .002.

For convenience in discussion, the laminations forming the roller bracket and push rod will be indicated by the following numerals. The top lamination 174, the one therebeneath 176, the lamination next to the bottom 178, and the bottom lamination 180. At the forward end, the two outer plates (that is, the plates 174 and 180) are % wide and are drilled to take the trunnion ends 184 of the roller 170. These two outer plates are riveted as at 186 and 188 to the intermediate plates 176 and 178. These intermediate plates are % wide and do not extend forwardly as far as the outer plates 174 and 180, thereby providing clearance as at 190 for the roller 170. The rearward portion 182 of the push rod is comprised of an extension of the intermediate % strip 178 which is longer than the two thereabove, along with a Vi width portion of the lower lamination 180. Near their rearward ends these strips 178 and 180 are additionally secured together by a rivet 192.

This laminated structure gives a bracket or mounting member for the roller 170 which is offset upwardly into alignment with the cam 78 with respect to the rearwardly extending push rod portion 182 which is closer to the central portion of the case interior. Inasmuch as the upper and lower laminations 174 and 180 respectively, where the four laminations are stacked, are % wide, while the two intermediate laminations 176 and 178 are % wide, the top and bottom laminations extend at the edges beyond those at the center, thereby providing side channels which embrace a pair of hat-shaped guide blocks 196 formed preferably of nylon or Delrin as is best seen in FIG. 10. These guide blocks and the embraced portion of the push rod are located within a generally rectangular passage formed between a recess 200 in the cover and a cap member 198 which is keyed thereto and secured to the cover by screws 201. It is necessary during assembly, therefore, merely to insert the guide blocks 196 into position at the sides of the push rod, and then drop the guide blocks and push rod into the recess 200 in the cover, after which the cap 198 is secured in place.

Toward the right of this guide assembly at the position where the push rod 182 is comprised of two Vi laminations, the push rod passes through a rectangular tubular plastic guide sleeve 202, similarly held in place between the bottom and top housing members, this sleeve having previously been slid over the right hand end of the push rod. A pair of screws 203 secure the case elements 42 and 46 together on each side of the guide sleeve 202 so as to strengthen the assembly at this position.

The sleeve 202 has an opening 204 in the top thereof in alignment with a hole closed by a screw plug 206 in the cover member 44. This plugged opening serves to vent the mechanism when it is being filled with oil, and is also used to aid in the assembly. When the plug is removed and the push rod is all the way to the right, it exposes a tapped opening 208 in the lamination 178 and a clearance opening 210 therebeneath in the lamination 180. The utility of this arrangement will be discussed subsequently.

To the right of the guide sleeve 202 the push rod projects into the end of a horizontally disposed hydraulic cylinder 212 fitted with a piston 214. Since the cylinder must be relatively small and the hydraulic pressures relatively high, a piston ring 216 is used to insure good sealing. The cylinder 212 is formed as a separate sleeve, of cast iron for instance, and at its forward end is provided with a portion of reduced external diameter having a ring groove 218 formed therein. The housing members 42 and 44 are formed as is best shown in FIG. 11 so that

3,149,366 they have surfaces therein which together comparatively closely embrace the front end of the cylinder when the cover 44 is fastened to the main portion of the housing. Inasmuch as these members are die castings however, this fit cannot be precise, and therefore, a slightly corrugated split ring 219 (sometimes called a wave spring) is slid over the end of the cylinder and snapped into the groove 218 prior to assembly. Subsequently, when the cover is clamped to the main portion of the housing, the corrugations in the wave spring are slightly flattened, thereby bringing the front end of the cylinder into proper alignment and clamping it tightly in place. The wave spring, indicated by the numeral 219, is best seen in FIG. 11.

At its rearward end the cylinder 212 is slid over a cylindrical boss 222 formed as a portion of a die cast block 224 having valves and other hydraulic passages therein to be described presently. Seal between these members is effected by a resilient O ring or similar member 226 fitted into a groove formed externally in the surface of the boss 222. This arrangement, therefore, forms a cylinder head toward which the piston moves as the door swings toward closed position.

On the cylinder head side, the piston is hollow, as is best seen in FIG. 4. Within the piston there is an axially located tubular guide member 228 having a flange 230 at its end which closely fits the interior dimension of the piston. It is held against the piston head by a coil spring 232 which bears thereagainst at one end, its opposite end bearing against the bottom of an annular groove 234 formed in the end of the cylinder head boss 222. This spring also acts to urge the piston 214 toward the left so that it engages the push rod and causes the roller 170 to follow the cam 78.

The tubular guide member 228 houses the base end of a molded nylon or Delrin pin 236 which is free to slide longitudinally within limits. The rearward end of this pin is hollow, and it contains a light spring 238 which urges the pin outwardly or toward the right with respect to the piston 214. The base end of the pin is enlarged as at 240, whereas the right hand end of the guide member 228 has a somewhat smaller opening which fits the smaller diameter portion of the pin, such that the spring 238 cannot project the pin 236 all of the way out of the guide member. At the head end of the piston, the end of the spring 238 fits over a small projection at the center of a plastic button 242 which is pressed into the end of the guide member 228. This prevents the left hand end of the spring from slipping to one side so as to inhibit free movement of the pin 236.

The above described piston and floating pin assembly may be very easily assembled since it is necessary merely to drop the pin 236 into place within the guide member 228, and then to insert the spring 238 and press in the button 242. This assembly is then placed inside the piston 214 and is retained in operative position by the spring 232 when the piston is put into the cylinder and the cylinder is secured to the block 224.

As is best seen in FIG. 12, the block 224, which contains various hydraulic valve mechanisms and which supports and closes the end of the cylinder 212, is positioned in the case by means of a pair of locating pins 250 fixed in the case bottom portion 42 and is retained by cap screws 252. The cap screws pass through the cover 44 and clamp the block between the cover and the bottom of the case 242. In this assembly all of the checking reaction is taken directly against the solidly mounted and pinned block 224, whereas the cylinder 212 need not be rigidly mounted, since it takes no substantial load in any direction.

The outward or right hand end of the pin 236 is comparatively sharp and acts as a needle valve in conjunction with the end of a passage 244 formed in the block 224 at the center line of the cylinder. The passage 244 is intersected by a downwardly extending passage 246 provided with an adjustable flow rate control valve 248.

The detailed description of this flow control valve, and a substantially identical valve to be mentioned subsequently will be postponed for the present.

Directly above the passage 244 there is a second passage 254 which is intersected by a downwardly extending passage 256 containing a ball check valve 258 which permits flow in the upward direction. The passage below the check valve leads to an intake port 259 in the bottom of the block 254, this port communicating with the space within the case exteriorly of the valve block. The valve ball 258 is dropped into place through an opening at the top of the block, which is subsequently closed by a plug 260 having a downwardly extending stem 262 which limits the upv/ard movement of the ball.

The passage 254 is also intersected by a transversely extending passage 264 which, as is best shown in FIG. 13, leads both to a second flow control valve 266 (similar to the valve 248) and also to a pressure release valve which comprises a ball 268 held in a socket against the pressure in the passage 254 by a leaf spring 270 retained by a screw 272.

Referring to the check valve 266 which may also serve as a model for the valve 248, it will be noted that it has a threaded portion 274 and an upwardly extending cylindrical stem 276 which closely fits the downwardly extending portion of the passage 264. The cylindrical stem 276 has a small triangular notch 278 formed at the upper end thereof such that as the adjusting screw is backed off, the notch 278 exposes more and more of the recess below the end of the passage 264 so as to permit a greater flow from the passage 264 through the notch 278 and to the outside through a port 280.

Between the slotted screw head 282 of the adjusting screw and the threaded portion 274, the screw has a pair of annular flanges 284 which confine an O ring 286 therebetween. These flanges are disposed within a cylindrical recess which is formed in the case member 42, and this recess has a smaller diameter, as at 288, where the head of the screw becomes accessible to the outside. Since the threaded portion 274 is fitted to a complementary portion formed in the block 224, and since the recess which receives the flanges 284 is formed in the case member 42, several advantages accrue. In the first place, it is not necessary that the passages in the die cast housing 42 be as precisely aligned with those in the block 224 as would otherwise be necessary, and yet leakage to the outside is sealed against by the O ring 286. Furthermore, since the flanges 284 have a diameter which is larger than the opening which receives the head of the screw 282, it is impossible for a user of the device to inadvertently back the screw all the way out while making an adjustment. There is no danger, therefore, of the screw becoming lost, nor of the hydraulic fluid running through to the outside by way of the port 280 as might happen if the adjusting screw were completely removed.

Somewhat to the right of the valve block 224 the cover is provided with an opening closed by a threaded plug 290. It is through this opening that the device is filled with hydraulic fluid after assembly. The case thus serves, as a reservoir for the hydraulic fluid, and the hydraulic, fluid also insures that all of the working parts are adequately lubricated.

In assembling the device, the spindle, including the cams and the closing subassembly of the apparatus, are put into the bottom of the case as previously described. Next, the cylinder and block are set in position. Then the subassembly, comprising the push rod and cam follower portion of the mechanism, is laid in the cover member 44 and the cap 198 secured in place. A screw is in-, serted through the opening closed by the plug 206 and threaded into the opening 208 of the push rod 182 and tightened. In order to do this, the push rod is pushed all the way to the right. This places the roller 170 in a position to clear the cam 78 when the cover is subsequently located. The cover is then turned over, the end of the push rod is inserted into the cylinder, the piston is pushed

3,149,366 to the right, and the cover is properly located and the various screws are put in place, including the pair, 203, previously mentioned, which straddle the guide sleeve 202 (FIG. 11) near the cylinder left end. All of the elements then will be brought into proper position as the screws are tightened, after which the temporary screw inserted into the push rod at 208 is removed.

The device is filled with hydraulic fluid through the opening normally closed by the plug 290, and during filling, air is expelled through the opening subsequently closed by the plug 206.

The door check operates in the following manner. When the door is swung toward open position, the cam 74 engages one of the rollers 92, urges it to the right, and compresses the springs 112 as previously described. During this movement, the spring 232 will push the piston 214 toward the left so that it follows the end of the push rod and urges the roller 170 into continuous contact with the cam 78. The pin 236 is withdrawn from the port 244, and the cylinder fills without restraint by unseating the check valve 258 so that hydraulic fluid flows into the cylinder by way of port 259 and passage 254.

When the door is released, the springs 112 swing the door toward closed position, and the cam 78 forces the push rod and piston 214 toward the right, thereby reducing the capacity of the space between the piston and the cylinder head 222. The major portion of the hydraulic fluid flows through the passage 244 and the fast swing regulating valve 248. If the door is forcibly swung toward the closed position so that the torque reaction becomes higher than normal, the spring 270 is slightly bent and the safety valve 268 is unseated so as to permit a high flow rate to the sump.

A minor portion of the hydraulic fluid flows outwardly through the passage 254 and control valve 266, this valve being regulated to provide for the low speed return movement of the door, usually referred to as the latching speed. Fifteen degrees or so before the door reaches its closed position, the pin 236 will enter and close the passage 244, so that all of the hydraulic fluid must then flow through the passage 254 and latching speed regulating valve 266. Preferably, the end of the pin 236 is tapered as shown, so that the transition between rapid and slow closing movement of the door is sufficiently gradual to avoid shock or noise in the system. Rapid closing movement of the door can therefore be set as desired, by adjusting the valve screw 248, whereas the slow latching final movement of the door is regulated by adjusting the valve screw 266, both of these being accessible to the bottom surface of the closer.

To adapt this closer to several ranges of closing torque, different springs 112 may be available having different characteristics. I have found that ordinarily three different spring sets will give the full range of closing torque previously mentioned and, as explained, adjustment within each of these ranges can be accomplished by turning the squared head 148 of the spring adjusting screw. The three springs I have selected, including full adjustment within each range, give the following characteristics: light springs, 15 to 27 ft. lb.; medium springs, 25 to 36 ft. lb.; heavy springs, 36 to 44 ft. lb.

Inasmuch as the cam 74 may have the stop member 99 at any position along its surface, and since the notch 100 also may be positioned as desired, it is no problem to provide checking mechanisms which accommodate different degrees of door swing, with or without the hold-open notch 100, it being necessary merely to use different cams 74 in the different models.

In the event that the door is overswung in the opening direction, so that the roller 92 drops into its notch 10® and tends to continue beyond this point, the screw heads 124 engage the ends 168 of the spring 162, thereby bringing the door to rest with a cushioning action that is semihydraulic in nature. As explained previously, this is be cause of the hydraulic fluid momentarily trapped between the spring 162 and backup plate 164.

Although I have illustrated and described my invention in terms of a specific embodiment thereof, it will be appreciated that modifications in the structure may be made without departing from the spirit or scope of the invention, and that the scope of the invention is to be measured in terms of the scope of the following claims.