Blank feeders for folding box machines

Oct. 5, 1965 τ. _R. baker etal 3,210,072

BLANK FEEDERS FOR FOLDING BOX MACHINES

Filed Oct. 29, 1963 6 Sheets-Sheet T

37 Vf

<img file="US3210072A_D0001.tif" />

_m INVENTOR.

Thomas R. Baker Chester J Pierce, Jr.

Di *·** ATTORNEY

Oct. 5, 1965 τ. r. baker etal 3,210,072

BLANK FEEDERS FOR FOLDING BOX MACHINES

Filed Oct. 29, 1963 . 6 Sheets-Sheet 2

<img file="US3210072A_D0002.tif" />

INVENTOR.

Thomas R. Baker

Chester J. Pierce, Jr,

BY attorney

Oct 5, 1965 τ. r baker etal 3,210,072

BLANK FEEDERS FOR FOLDING BOX MACHINES

Filed Oct. 29, 1963

Sheets-Sheet 3

<img file="US3210072A_D0003.tif" />

INVENTOR. Thomas R. Baker Chester J. Pierce, Jr.

A TTORNEY

Oct 5, 1965 τ. r. baker etal 3,210,072

BLANK FEEDERS FOR FOLDING BOX MACHINES

Filed Oct. 29, 1963

Sheets-Sheet 4

<img file="US3210072A_D0004.tif" />

<img file="US3210072A_D0005.tif" />

Oct. 5, 1965 τ. R. baker etal 3,210,072

BLANK FEEDERS FOR FOLDING BOX MACHINES Filed Oct. 29, 1963 6 Sheets-Sheet 5

<img file="US3210072A_D0006.tif" />

INVENTOR.

Thomas R. Baker

Chester J. Pierce, Jr. BY

ATTORNEY

Oct. 5, 1965 T. R BAKER ETAL 3,210,072

BLANK FEEDERS FOR FOLDING BOX MACHINES

<img file="US3210072A_D0007.tif" />

Chester J. Pierce, Jr.

BY

ATTORNEY

United States Patent Office _Patented * ai©m©ci vj x«?oo the stack of blanks in the magazine the pressure on the magazine gate is greatly diminished and misfeeding may result from failure of the blanks to advance properly.

In addition, the entire reloading operation is awkward for the operator who needs both hands to handle the new batch of blanks to be inserted.

According to the invention the need for a pusher is 5 eliminated, so that a magazine of great blank capacity may be reloaded at anytime and without inconvenience. The invention is based on the discovery that there is a range of inclinations of the magazine rods within which range the weight of the blanks is sufficient to cause the 10 blanks to advance towards the gate under the action of gravity, yet the angular inclination is small enough so as not to result in an appreciable difference in pressure on the gate between the condition in which the magazine is almost empty and the stack is short, and the condition 15 in which the magazine is fully loaded and the stack is long.

The invention further deals with the problem which arises from the pounding of the oscillating blank transport means against the front end of the stack. In pusher20 equipped magazines the pounding causes no difficulties, but in a pusherless assembly there is the danger that the pounding causes the blanks in a short stack to be knocked over into the flat and shingled position on the supporting rods, in which position they cannot be grasped by the 25 suction cup and also fail to advance.

The invention will appeair more fully from the detailed description which follows accompanied by drawings showing, for the purpose of illustration, a preferred embodiment of the invention. The invention also resides in 30 certain new and original features of construction and combination of elements hereinafter set forth and claimed.

Although the characteristic features of this invention which are believed to be novel will be particularly pointed out in the claims appended hereto, the invention itself, 35 its objects and advantages, and the manner in which it may be carried out may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part of it in which:

FIG. 1 is a perspective view of a blank magazine and 40 transport mechanism embodying the invention;

FIG.· 2 is a perspective closeup view of a portion of the mechanism of FIG. 1;

FIG. 3 is a perspective view of the magazine gate portion of the device;

FIG. 4 is an elevational view showing a detail of the blank transport mechanism;

FIG. 5 is a perspective view of the magazine operating mechanism underneath the rear portion of the magazine;

FIG. 6 is a perspective view of another portion of 50 the operating mechanism; and

FIG. 7 is a perspective closeup view of the magazine gate and a short stack of blanks illustrating a specific operating condition.

In the following description and in the claims various 55 details will be identified by specific names for convenience. These names, however, are intended to be generic in their application. Corresponding reference characters refer to corresponding parts in the several figures of the drawings.

The drawings accompanying, and forming part of, this specification disclose certain specific details of construction for the purpose of explanation of broader aspects of the invention, but it should be understood that structural details may be modified in various respects without de-

3,210,072

BLANK FEEDERS FOR FOLDING BOX MACHINES

Thomas R. Baker, Los Altos, and Chester J. Pierce, Jr., Palo Alto, Calif., assignors, by mesne assignments, to Bradford Speed Packaging and Development Corp., New York, N.Y., a corporation of Delaware

Filed Oct. 29,1963, Ser. No. 319,716 9 Claims. (Cl. 271—30)

This invention relates to improvements in blank feeders of the type in which a periodically operated blank transport means fitted with one or several suction cups removes individual folding box blanks through the withdrawal gate of a magazine containing a stack of blanks.

The magazine gate comprises appropriate means, for example one or several lips which marginally overlie the foremost blank of the stack, for preventing the blank from dropping out under the pressure of the stack of blanks behind it. The foremost blank is distorted or flexed when the suction cup of the transport means attaches itself to the blank and begins to pull it away from the stack, the degree of flexing or distortion being sufficient for the blank to clear the retaining element or elements.

Blank magazines are known in which the stack is vertical, or nearly so. The disadvantage of this arrangement is that the force required for withdrawal of the foremost blank varies in direct proportion to the height of the stack. The permissible height is generally low and must be kept within close limits to insure proper feeder operation. This, in turn, requires frequent reloading of the magazine.

Magazines are also known in which the stack is nearly horizontal or slightly inclined. This arrangement offers the advantage that the pressure of the stack on the magazine gate varies little with the height, or rather length, of the stack. A greater number of blanks may therefore be loaded at one time into a blank magazine of the latter type. The running time of the box machine between periods of reloading is long, and one operator can supervise a greater number of machines than in the case of vertical stacks.

Blank feeders with horizontal or slightly inclined magazines have undergone considerable refinement to eliminate the friction between the blanks and the magazine. It is known in this connection to rest the blanks on edge or cylindrical rods which are either rotated or oscillated to reduce friction. This, however, is . not enough to cause the stack to advance towards the gate where blanks are continuously being withdrawn. It has therefore been necessary to employ a pusher, also called follower, at the back of the stack to push the stack towards the gate, either by the force of a spring pulling the pusher towards the gate, or by a pull-cable-and-weight arrangement, the latter offering the advantage of exerting a force of equal magnitude for close and distant positions of the pusher with respect to the gate.

The presence of a pusher is a considerable inconvenience in reloading the magazine, as the pusher must be separated from the rearmost blank in the stack to permit a batch of blanks to be inserted in the space so created.

During the period of separation of the pusher from parture from the principles of the invention and that the invention may be incorporated in other structural forms than shown.

3,210,072

The folding box machine shown in FIG. I comprises a machine base or frame 11 on which a magazine gate 12 is mounted at 13 and 14. Four rods 15, 16, 17 and 18 extend rearwardly from the gate 12 and are supported in a rear bracket 19 on the machine base 11.

The inner pair 15, 16 of the rods are rotatably mounted on the gate 12 and the rear bracket, respectively, and support a stack 20 of folding box blanks B which rest on the rods 15,16 on edge.

The outer pair of rods 17,18 lie slightly above the rods 15, 16, are stationary, and engage the blanks B laterally, so as to keep them lined up (see also FIG. 2).

The gate 12 is fitted with lip elements 21 marginally overlapping the leading surface of the foremost blank adjacent its upper edge, and lateral lip elements 22 which marginally overlap the foremost blank at its lateral edges in order to prevent the blank from dropping out of the magazine gate under the pressure of the stack of blanks behind (see also FIG. 3).

A reciprocating blank transport means is provided for grasping the foremost blank of the stack 20 and pulling it out of the gate past the retaining lips 21, 22. In the illustrated form of device the transport means comprise two vacuum cup assemblies 23 mounted on a common mounting plate 24 which, in turn, is secured to an arm 25 on an oscillating shaft 26 to which the arm 25 is keyed at 27 and clamped at 28. A flexible vacuum line 29 extends to the suction cups and applies vacuum at regular intervals, as is known in the art (see FIG. 4).

FIG. 2 shows the transport means at the moment of engaging and withdrawing a blank, FIG. 1 shows the transport means in the act of moving the withdrawn blank towards a conveyor 30 which is of no further importance in considering the present invention and improvement, and FIG. 3 shows the transport means at about the end of its withdrawal stroke, which is the beginning of its return stroke toward the magazine.

The inner pair of rods 15, 16 which support the weight of the blanks is agitated for the purpose of reducing the friction between the blanks of the stack and the rods. To this end the rods are given a rotary motion about their axes. It is sufficient to limit the rotation to a fraction of one revolution, in other words, it is sufficient to oscillate the rods through a predetermined arc.

As seen in FIG. 1, an arm 31 is attached to the rod 15 near its upper end and a link 32 extends from the arm 31 to a further arm 33 on an oscillating square bar 34 pivotally mounted at 35. A similar arm and link assembly connects the rod 16 with the oscillating bar 34, but is obscured in FIG. 1 by the stack of blanks 20.

Another arm is connected to the square bar 34 at 36 (FIG. 1). The other end of the arm is seen at 37 in FIG. 5. A connecting rod 38 extends from the lower portion of 37 of the arm to a pendulous lever 39 secured to a transverse shaft 40 in the machine base. A connecting rod 41 leads from the end of the lever 39 to a crank 42 on a rotating shaft 43.

As the crank 42 is rotated, the lever 39 moves back and forth in a pendulous fashion and causes the blank supporting rods 15 and 16 to be oscillated through the operating linkage and the arm assembly 38, 37, 34, 33, 32, 31.

The mechanical drive may be traced further in FIG. 6 showing a portion of the machine of FIG. 1 after removal of a protecting housing 44 normally covering gears and chains.

The shaft 43 is driven by a power or drive chain 45 trained over a sprocket gear 46 on the shaft 43. The shaft is supported in a bearing 47 on a mounting plate 48 and carries an outer crank 49 from which a connecting rod 50 extends to an arm 55 on the keyed shaft 26 which carries the blank transport assembly including the suction cups 23.

As the chain 45 is driven, the shaft 26 oscillates, the suction cups 23 move back and forth, the shaft 43 ro4 tales and causes oscillation of the blank supporting rods, as previously described.

Experiments were conducted to determine the possibility of eliminating the blank follower or pusher which, 5 according to conventional practice, was employed in order to advance the stack of blanks towards the magazine gate, as blanks are being removed therethrough.

For this purpose the inclination of the rods angle a was varied, and it was found that for inclinations ex10 ceeding 40 degrees the pressure produced by the weight of the stack on the retaining lips on the gate becomes so great when the stack is long, or tall, as to interfere with the proper removal of blanks. Furthermore, the pressure varies too greatly, depending on the size of the stack, 15 to make the operation dependable. At the other end of the range it was found that an inclination of less than 15 degrees causes unreliable advance of the stack in spite of agitation of the rods 15,16. The range of 15 to 40 degrees was found to be satisfactory for large as well as 20 short stacks of blanks and no feeding difficulties are encountered. The absence of a pusher, or follower at the rear of the stack is a great improvement and convenience in that a great number of blanks may be loaded at once without interference by, or need for removal of, a pusher. 25 The 15 to 40 degree tilt permits long operating periods without supervision.

In the event the stack is permitted to become nearly exhausted before reloading, a condition arises in which the pounding of the reciprocating transport means causes 30 the rearmost blanks to be tipped over. This condition is shown in FIG. 7.

Means may be provided for retaining the blanks upright. Basically the means comprises a catch or finger element which is movable either into one position to 35 engage a blank adjacent an edge, preferably the top edge at the trailing surface of the blank, or into another position in which it clears the blank. The movement of the element is controlled in dependence on the presence or absence of blanks rearwardly, i.e., upstream, of the catch 40 or finger. Thus the device comes into operation when the stack of blanks becomes short which is the condition iri which the danger arises of blanks being tipped over, as shown in FIG. 7.

A representative form of assembly is shown in FIGS. 45 I^-3· The catch proper or tip of the arresting finger is the end 51 of a flat spring having a body portion 52 and a mounting end 53 at which it is secured to a bracket 54 attached to the gate 12 and exending rearwardly of the gate over the magazine rods and the stack 20 of blanks ₅₀ thereon.

As seen in FIG. 2, the spring, when relaxed, assumes a position in which its free end or tip 51 lies behind the trailing surface of the last blank of the stack adjacent the top edge of the blank. Pounding of the reciprocating 55 blank transport means cannot knock the blanks over, as they come to rest against the catch finger 51. If the magazine is reloaded, blanks upstream of the tip 51 engage the body portion 52 and deflect the catch into disengaged position (FIGS. 1 and 3). In this condition the θθ mass of the long stack of blanks is sufficient to absorb the pounding of the blank transport means without danger of blanks tipping over.