Concrete surface finishing apparatus

Dec. 31, 1968

η. w. wilson 3,418,902

CONCRETE SURFACE FINISHING APPARATUS

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ATTORNEY

Dec. 31, 1968

H. W. WILSON

3,418,902

CONCRETE SURFACE FINISHING APPARATUS

Filed April 18, 1966

Sheet 2 of 3

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ATTORNEY

Dec. 31, 1968 h. w. wilson 3,418,902

CONCRETE SURFACE FINISHING APPARATUS Filed April 18, 1966 _{Sheet 3 of 3}

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ATTORNEY

United States Patent Office 3,418,902

Patented Dec. 31, 1968

3,418,902

CONCRETE SURFACE FINISHING APPARATUS

Herbert W. Wilson, Rte. 1, Box 457, Abilene, Tex. 79601

Filed Apr. 18, 1966, Ser. No. 543,273

Claims. (CI. 94—45)

ABSTRACT OF THE DISCLOSURE

A concrete surface finishing apparatus includes a pair of wheeled carriages which move along a preselected path on opposite sides of a concrete surface. A pair of spaced apart truss frameworks span the concrete surface and are slidably supported in rolling engagement at the opposite ends by rollers on each of the wheeled carriages.. A screed member is carried on the bottom of each of the truss frameworks for engaging and working the concrete surface. A driving motor supported by one of the truss frameworks includes a lever arm connected to the other of the truss frameworks for relatively reciprocating the truss frameworks to cause the screed members to finish the concrete surface.

This invention relates to an apparatus for finishing a concrete surface, and more particularly to a concrete surface finishing apparatus which spans the surface of the concrete to be finished and has reciprocating screed members which engage and work the concrete surface.

There are various types of concrete finishing apparatuses which employ screed members for finishing the surface of the concrete immediately after the concrete is poured. Some of these apparatuses are adapted to oscillate or reciprocate the screed members in various manners for finishing the concrete surface, and in addition to which some are adapted to vary the contour of the screed members to effect selected crown configurations of the concrete surface. Such an apparatus has particular application to the finishing of a bridge deck, wherein the portability and mobility of the apparatus is of prime importance. For bridge deck applications, the weight of the apparatus becomes a factor so as not to subject the elevated bridge structure to an excessive load during construction. Although these apparatuses have a particular utility for finishing bridge decks, they are also useful in the finishing of concrete surfaces of road beds.

It is with respect to this particular type of apparatus that the present invention is directed as an improvement thereof. In one aspect, the present invention is directed to the provision of an apparatus very light in weight which is particularly suitable for finishing concrete surfaces of a bridge deck. The invention is also directed to the provision of an apparatus which is highly portable as a result of its light weight. Another consideration is the provision of such an apparatus that is simple in construction and adequately powered to provide an effective finishing action for a concrete surface, yet which is able to withstand the various stresses and strains to which such an apparatus is subjected during operation. These particular objects are accomplished as the result of the novel structural arrangement of the apparatus employing a minimum number of parts and structural elements. As a result, another object of the invention is achieved, which is the provision of such an apparatus that is economical to manufacture.

In accordance with the above objects, the apparatus of the invention includes a pair of spaced apart, wheeled carriages adapted to run on a pair of tracks situated on opposite sides of the concrete surface to be finished and running parallel therewith. A pair of truss frameworks which span the concrete surface to be finished are sup2 ported at their opposite ends by the carriages, wherein each truss framework includes a screed member along the bottom thereof for engaging and working the concrete surface. The truss frameworks are supported at their op5 posite ends by the respective carriages in parallel and spaced apart relation, wherein the truss frameworks include support members which project through housings in the carriages and are supported therein on roller means, the latter of which allow the truss frameworks to be 10 reciprocated back and forth within the housings of the carriages laterally with respect to the line of travel of the apparatus. A driving means, such as a gasoline motor, is structurally supported on one of the truss frameworks for movement therewith and is coupled by a crank arm to 15 the other truss framework. Actuation of the driving means causes the truss framework which is coupled to the driving means by a crank arm to 'be reciprocated, whereby the other truss framework is caused to be reciprocated relative or oppositely to the first truss framework as a re20 suit of the equal and opposite reaction of the crank arm.

Thus it will be seen that a very simple driving means is employed for reciprocating both truss frameworks in opposite manners, and that the main structure of the apparatus, which comprises the two truss frameworks, is 25 reciprocated with the screed members. This obviates the necessity of large structural frameworks for supporting additional frameworks which are reciprocable. The apparatus of the invention is also adjustable in height from the tracks on which the carriages roll in order to adjust 30 the screed members to the proper elevation. Moreover, very simple means are provided for varying the contour of the screed members to provide selected crown configurations of the concrete surface. To provide this, the truss frameworks of the apparatus are constructed in separate 35 segments along the top, and between adjacent segments there are provided simple manual adjustment means for adjusting the separations between the sections. All of the truss sections are rigidly secured at the lower ends thereof to the screed members so that variations of the separa40 tions 'between the adjacent truss sections cause the screed members to be bowed accordingly to adjust the contour thereof.

There are many other objects, features and advantages of the present invention that will become readily apparent 45 from the following detailed description of a preferred embodiment thereof when taken in conjunction with the appended claims and the attached drawing wherein like reference numerals refer to like parts throughout the several figures, and in which:

FIGURE 1 is a front elevational view, partly broken away, of the apparatus of the invention;

FIGURE 2 is a top plan view of the apparatus;

FIGURE 3 is an elevational view in section of the two truss frameworks of the apparatus taken through section 55 lines 3—3 of FIGURE 1;

FIGURE 4 is an end elevational view of the apparatus, with some of the components of the apparatus shown in phantom;

FIGURE 5 is an elevational view in section of the ap60 paratus taken through section lines 5—5 of FIGURE 1;

FIGURE 6 is a rear elevational view of one end of the apparatus, shown partly in section; and

FIGURE 7, is a fragmentary, elevational view in section of a manual screed contour adjustment means.

Referring now to the front elevational view of the apparatus shown in FIGURE 1, the apparatus includes a pair of spaced apart, wheeled carriages generally designated at numerals 10 and 12 which are adapted to roll along a pair of tracks. 11 and 13, respectively, the latter 70 of which are situated on opposite sides of a bridge deck, or road surface as the case may be, and running parallel therewith. The purpose of the carriages is to support

3,418,902 truss frameworks which carry screed members for working a concrete surface, and are adjustable to adjust the height of the screed members to the proper elevation. A pair of vertical truss frameworks 14 and 16, shown in FIGURES 1-3, span the width of the concrete surface or deck to be worked and are supported at their opposite ends in carriages 10 and 12. These truss frameworks are spaced apart in substantially parallel relationship with each other, whereby the truss frameworks are adapted to be reciprocated relative to each other as will be described hereinafter. A pair of spaced apart screed members. 18 and 20 form the lower part of the two truss frameworks 14 and 16, respectively, whereby the screed members are relatively flexible for being bowed to provide selected crown configurations of the concrete surface. Truss framework 14 includes a pair of support members 54 and 56 which are supported with carriages 10 and 12, respectively, in rolling engagement therewith, so that truss framework .14 can be reciprocated laterally with respect to the movement of the apparatus. The members 54 and 56 support the truss framework 14, carriages 10 and 12 support the truss framework 14 through members 54 and 56, respectively, and the tracks 11 and 13 support carriages 10 and 12, respectively. Similar support members 55 and 57 are included in truss framework 16 and are supported in rolling engagement with carriages 10 and 12, respectively, for the same purpose. A more detailed description of the truss, frameworks will be set forth below, wherein a more general description of the apparatus in its function will now be given.

A suitable driving means 22, such as a gasoline motor, for example, is rigidly supported from one of the truss frameworks .16 for movement therewith by means of a motor base 24 secured to the bottom of support members 57 of truss framework 16. The driving means is situated between the two truss frameworks 14 and 16 and is connected to truss framework 14 only by a coupling means as will be described. A sprocket 26 is driven by the motor and drives a larger sprocket 28 through a chain 30. Sprocket 28 is connected to a drive wheel 34 through a suitably supported shaft 27, and a crank arm 32 is pivotally connected at one end to the wheel 34 eccentric of the axis of rotation thereof and is pivotally connected at its other end to a structural member 36 forming a part of support member 56. Actuation of the driving means 22 causes truss framework 14 to be reciprocated by means of crank arm 32 laterally with respect to the line of movement of the apparatus on the rails, and the equal and opposite reaction of the driving means in response thereto causes truss framework 16 to be oppositely reciprocated as a result of the driving means, being rigidly connected to truss framework 16. Because of this structural arrangement and driving means, the apparatus is greatly simplified and requires only a single crank arm. It will be apparent that as the truss frameworks are reciprocated, the support members associated therewith move relative to the carriages.

To provide additional support for the truss frameworks, a plurality of spaced apart, connecting truss frameworks are provided for interconnecting truss frameworks 14 and 16 in hinged relation, as shown in the elevational view in section of FIGURE 3 taken through section lines 3—3 of FIGURE 1, and as shown in FIGURE 1. The interconnecting truss frameworks comprise horizontal members 40 and 44 hingedly connected at their opposite ends, respectively, to the truss framework 14 and 16. It will be seen that a plurality of these interconnecting truss frameworks are provided in spaced apart relation along the lengths of the main truss frameworks 14 and 16. Horizontal member 40 is connected at one end to the upper end of truss, framework 14 by means of a hinge 41, and is connected at its other end to the top of truss framework 16 by means of another hinge 42. Similarly, horizontal member 44 is connected at one end to the lower end of truss framework 14 by means of a hinge 45 and at its other end to the lower end of truss framework 16 by means of another hinge 46. Members 48 rigidly interconnect horizontal members 40 and 44 to provide additional strength therefor. It will be obvious that as the truss frameworks. 14 and 16 reciprocate relative to each other, the interconnecting truss frameworks are caused to swing in accordance therewith. As a result of the interconnecting truss frameworks, the two main truss frameworks 14 and 16 will be brought closer together when they are disposed at relatively reciprocated positions with each other. However, the lateral limits of movements of the truss frameworks and screed members are small as compared to the overall length of the truss frameworks, and consequently, the distance of separation between truss frameworks 14 and 16 varies only slightly.

The main truss frameworks 14 and 16 are comprised of vertical structural members 50 and 52, respectively, connected at the lower ends thereof to the screed members 18 and 20, respectively. A plurality of these vertical members are provided along the lengths of the truss frameworks. The upper parts of the truss frameworks are comprised of a plurality of horizontal members providing the upper support for the vertical members. In particular, truss framework 14 comprises, a plurality of separate members 15 and 15' which are spaced apart but connected by a manual adjustment means 60. Similarly, truss frameworks 16 includes a plurality of separated section 17 and 17' which are spaced apart but connected by manual adjustment means 62. The manual adjustment means, which will be described in more detail below, comprises, a screw means with oppositely threaded ends screwed into the adjacent truss members. Rotation of the member in one direction causes the two adjacent truss sections to be brought closer together and rotation of the member in an opposite direction causes the separation of the two adjacent truss sections to be increased. This results in the section of the screed member which corresponds to the truss section including the manual adjustment means to be bowed accordingly to provide selected crown configurations of the concrete surface. To provide further structural support for the main truss sections, additional structural member 66 is provided between selected vertical bars 50 in truss framework 14, and similar members are provided for truss framework 16. It will be noted that a plurality of the manual adjustment means 60 are provided along the top of truss framework 14 at selected intervals, and that these manual adjustment means, are provided between only some of the vertical members. It will be apparent that the additional structural members 66 cannot be provided between adjacent vertical members 50 between which there is provided a manual adjustment means, since this would prevent the spreading between the two vertical members thereof. Thus the additional structural members 66 are provided only between those adjacent vertical members which do not include a manual adjustment means.

Reference will now be had to all of FIGURES 1, 2, and 4-6, with particular reference to FIGURES 4—6, for a description of the wheeled carriages which support the vertical truss frameworks. Referring particular to FIGURE 4, which is a view of the end of the apparatus which includes the driving means for the reciprocating the screed members, a channel 70 through which support members 56 passes is provided adjacent one end of the carriage and includes roller means therein on which support member 56 rides in rolling engagement. The roller means comprises a pair of spaced apart rollers 71 and 72 rotatably mounted within the housing or channel as more clearly seen in phantom in FIGURE 1. A corresponding channel is provided in carriage 10 for supporting member 54 in rolling engagement. The two channels of the two carriages 10 and 12 are aligned with truss framework 14 and the respective support members associated therewith. Another channel 74 is provided adjacent

3,418,902 the other end of carriage 12 and includes another pair of roller means, only one of which is shown at 76 in FIGURE 4. A corresponding channel is provided in carriage 10, with these two channels being aligned with truss framework 16. Carriage 12 comprises a main horizontal structural member 68 for supporting the channels. Each of the channels has an inside width slightly greater than the width of the support members which pass therethrough, so that as the truss frameworks and the corresponding screed members are reciprocated, the support members engaging the roller means within the channels can move sideways within the limits required by the bringing of the truss frameworks 14 and 16 closer together. It will be recalled that this occurs because of the hinged interconnection of the truss frameworks by the interconnecting truss structures spaced along the lengths thereof. Connecting bars 40' and 44' are connected by hinges at their ends to frameworks 14 and 16 above and below the driving means to provide additional strength on this end of the apparatus.

The structural arrangement of the motor mounting base 24 is seen more clearly in the elevation view in section of FIGURE 5, taken through section lines 5-5 of FIGURE 6. Motor 22 is supported on a motor base 24, and the latter is rigidly secured, as by welding, at one end 24α to the underside of support member 57, wherein an adequate clearance is left between the motor base 24 and support member 56. The base 24 is thus rigidly supported from support member 57 in a cantilever relationship, with no connection between end 246 and support member 56. It will thus be seen that the motor is rigidly supported solely from truss framework 16 by means of the support member 57, and that the only connection between the motor and truss framework 14 is by means of the crank arm 32. The relative reciprocation of the two screed members and associated truss frameworks as a result of the driving means is therefore apparent.

From the foregoing description, it will be seen that both truss frameworks 14 and 16 and the driving means associated therewith are free to move laterally with respect to the line of travel of the apparatus along the rails and with respect to the two carriages, it being understood that any motion of the truss frameworks parallel with the line of travel of the apparatus will be within the limits of the carriage housings through which the support members pass. Unless the truss frameworks are anchored to a part of the apparatus that is fixed against any lateral movement, the truss frameworks and associated screed members will have a tendency to work closer to one carriage than the other as they are reciprocated. To maintain the screed members and truss frameworks centered between the pair of carriages, an anchor means is provided which maintains the mean or average position of the screed members and truss frameworks fixed relative to one of the carriages, but which in no way hinders the reciprocation of the screed members and truss frameworks. Referring particularly to FIGURE 6, which is an elevational view, partly in section, of the end of the apparatus that supports the driving means, a bar 90 is pivotally attached by a collar 91 to a bolt means 92, the latter of which is secured to the main body 68 of carriage 12 with a suitable spacer or collar 93 between the carriage 68 and collar 91 of rod 90. This rod is anchored to the carriage midway between the two channels 70 and 74 and extends laterally between truss frameworks 14 and 16 to a point along a line between the ends of support members 56 and 57, as shown more clearly in FIGURE 2. Referring to FIGURES 2, 4 and 6, bar 90 is pivotally attached to a cross bar 96 by means of a fork 94 and cross bar 96 extends laterally with respect to bar 90 adjacent the inside surfaces of support member 56 and 57. Another bolt means 103 is secured to the inside wall of support member 56 by means of a collar 100, and includes shoulders or washers 101 and 102 at the lower end there6 of. Cross bar 96 is pivotally attached at one end to bolt means 103 by a collar 106 disposed about the bolt between the washers. Similarly, another bolt means 113 is secured to the inside wall of support member 57 by means of a collar 110 and includes washers 111 and 112 between which the other end of cross bar 96 is pivotally attached by a collar 116. One of the bolt means 103, for example, is seen attached to support member 56 more clearly in FIGURE 6, whereas the attachment of the cross bar to both of these bolt means is more clearly seen in FIGURES 2 and 4. As the screed members and truss frameworks are caused to be reciprocated relatively to each other, cross bar 96 will swing back and forth accordingly as do the interconnecting truss frameworks that are hingedly connected between the main truss frameworks 14 and 16. However, bar 90 maintains the position of the center of cross bar 96 essentially fixed so that the average or mean position of the screed members and truss frameworks remain fixed.

The elevation of the screed members can be adjusted to the proper height for working the concrete surface, whereby the carriages that support the main truss frameworks and screed members provide this function. Referring again to FIGURE 4, carriage 12 includes a generally Ushaped housing 130 (also seen in FIGURE 1) attached to the main body 68 of the carriage through channel 70. A wheel assembly 132, including a wheel 134 mounted on an axle therein, is pivotally attached within the housing adjacent the channel 70 by means of a bolt 133. A threaded member 136 is threaded through housing 130 and engages the top of the wheel assembly at its lower end, whereby the end of the threaded member below the housing 130 can be varied by rotation through a crank handle 138. By so doing, this end of the carriage can be raised or lowered with respect to track 13. A suitable electric motor 140 is secured to the outside of the wheel assembly and coupled directly to the axle on which wheel 134 rotates so that the entire apparatus can be moved along the track as desired. The corresponding end of the other carriage on the other side of the apparatus is similarly constructed and also includes an electric motor for driving this end of the apparatus or the other rail.

The other end of carriage 12 is similarly constructed and includes a generally U-shaped housing 150 secured to the main body 68 of the carriage through channel 74, with a wheel assembly 152 pivotally secured adjacent channel 74 by means of a bolt 153. The wheel assembly includes a wheel 154 mounted on an axle within the wheel assembly for riding on the track. Another threaded member 156 is threaded through housing 150 to engage the wheel assembly, and can be driven in and out of the housing by means of a crank handle 158.

The track 13 is preferably supported above the ground surface by means of any suitable spacer members that are variable to adjust the elevation of the track. As shown in FIGURE 4, jack members comprising a housing 158, with a suitable base thereon, and a threaded member 159 for supporting the track is positioned at one point under the track for support. Similarly, a plurality of other spaced apart jack members are employed, such as housing 160 and threaded member 161 for supporting another section of the track. The elevation of these jack members can be varied as desired to adjust the elevation of the track 13.

A fragmentary, elevational view in section of the manual adjustment means for varying the contour of the screened members is shown in FIGURE 7. The manual adjustment means 60 comprises a double shank bolt means having a shoulder 182 which can be rotated with any suitable wrench, and first and second oppositely extending shanks 180 and 181 which are oppositely threaded. One shank 180 is secured to one of the upper truss members 15 in threaded engagement therewith, and the other shank 181 is secured to an adjacent upper truss member 115' in threaded engagement therewith. As the bolt is

3,418,902 turned in one direction, adjacent truss members 15 and 15' are caused to be brought closer together, whereas rotation of the bolt means in the opposite direction causes the separation between the truss members 15 and 15' to be increased. This causes a corresponding moment or torque to be applied to the part of the screed member which corresponds vertically with the manual adjustment means through the vertical truss members 50. As a result, the contour of the screed member is varied accordingly. By providing a plurality of the manual adjustment means along the length of each of the truss frameworks 14 and 16, a smooth contour of the screed member can be effected, which contour can be varied or adjusted to provide the desired crown configuration of the concrete surface.

Although the foregoing description has had reference to a preferred embodiment of the invention, there are certain modifications and substitutions that do not depart from the true scope of the invention that will undoubtedly occur to those skilled in the art. Therefore, it is intended that the invention be limited only as defined in the appended claims.