US2822907A - Automatic control mechanism - Google Patents

Description

Feb. 11, 1958 G. M. BONEBRAKE I AUTOMATIC CONTROL MECHANISM 5 Sheets-Sheet 1 Filed Dec. 30, 1955 I N VEN TOR.

Gay M. 50 nebrake W7 flfiorney Feb. 11, 1958 G. M. BONEBRAKE AUTOMATIC CONTROL MECHANISM 3 Sheets-Sheet 2 Filed Dec. 50, 1955 IN V EN TOR. flay 1V2. flozzebrake Feb. 11, 1958 G. M. BONEBRAKE AUTOMATIC CONTROL MECHANISM 3 SheetsSheet 3 Filed Dec. 50; 1955 mu mm m m m 6 United States Patent AUTOMATIC CONTROL MECHANISM Gay M. Bonebrake, Chicago, Ill., assignor to Wm. Wrigley Jr. Company, Chicago, IlL, a corporation of Delaware Application December 30, 1955, Serial No. 556,570

1 Claim. (Cl. 192125) This invention relates to automatic control mechanisms, and more particularly to such mechanisms which are adapted to actuation by damaged, defective or jammed workpieces and the like in machines which normally operate for continuous periods to perform one or more operation on each of a series of workpieces, and which control mechanisms, when actuated as aforesaid, effect stoppage of the machine with which they are associated.

One of the general objects of this invention is to provide a safety control mechanism located adjacent the path of movement of workpieces through a machine and adapted to eifect the stoppage of the continuous operation of the machine in the event that a workpiece becomes abnormally displaced from the path or is defective in shape or size, so as to cause jamming or a tendency to jam in the machine.

Another object of my invention is to provide automatic mechanisms for eifecting stoppage of the normally continuous operation of a machine wherein slabs of relatively soft and flexible material are moved in paths by driven pusher-type machine parts, and wherein the control mechanism embodies movable elements in positions to be deflected by abnormally flexed portions of the slabs to efiect the stoppage without appreciable waste of material.

As another object, my invention has within its purview the provision of a control mechanism for use on a machine wherein slabs of gum or the like are fed from a stack to a breaking mechanism, and wherein abnormal fiexure of a portion of the slab will actuate the control mechanism to stop the machine.

These and other objects of this invention will become apparent from the following detailed description when taken together with the accompanying drawings in which:

Fig. 1 is a diagrammatic front elevational view depicting the adaptation of one form of my automaticcontrol mechanism to a machine which, in the disclosed embodiment, is adapted to the transfer of workpieces in the form of thin slabs of material from a stack in a hopper to another part of the machine at which operations are performed on the workpiece;

Fig. 2 is a fragmentary end elevational view of a portion of the control mechanism illustrated in Fig. 1, and is taken substantially as indicated by a line 22 in Fig. l and in the direction of the arrows;

Fig. 3 is a fragmentary structural view of a portion of the control mechanism shown in Fig. 1, and is drawn to a larger scale than Fig. 1, as well as having parts in section for indicating details of structure;

Fig. 4 is a fragmentary end sectional view of a portion of the machine and mechanism shown in Fig. 1, and is taken substantially as indicated by a line 44 and accompanying arrows in Fig. 1;

Fig. 5 is a fragmentary top plan view of the portion of the mechanism illustrated in Fig. 3;

Fig; 6 is a fragmentary end elevational view of the machine and mechanism depicted in Fig. l, and includes a structural illustration of another form of my automatic control mechanism in an application to the machine shown in Fig. l and utilized in addition to the control mechanism which is illustrated in Figs. 1 to 5 inclusive;

Fig. 7 is a fragmentary end sectional view of a portion 2,822,907 P atented Feb. 11, 1958 of the structure of my automatic control mechanism which is shown in Fig. 6;

Fig. 8 is another fragmentary end sectional view of a portion of the machine and mechanism depicted in Fig. 6, and illustrates details of the structure of the control mechanism of Fig. 6 and its application in the illustrated exemplary adaptation;

Fig. 9 is a fragmentary top plan view of the machine and mechanism shown in Fig. 6; and

Fig. 10 is a fragmentary front elevational view of the machine and mechanism depicted in Figs. 6 and 9.

The structural details and operating parts of the machine to which my automatic control mechanism are depicted as being applied in this exemplary illustration of my invention are more fully disclosed and described in my copending application Serial No. 270,636, entitled Apparatus for Removing Slabs From a Stack and Converting the Slabs to Smaller Pieces, filed February 8, 1952. However, suiiicient details of the machine and its operation are illustrated and described herein to disclose the adaptation of preferred forms of my automatic control mechanism thereto and to afford an exemplary embodiment of my invention for illustrative purposes.

A machine 15 is herein illustrated which is adapted to receive stacked slabs 16 of sheet material, such as chewing gum, in a hopper 17, and to transfer such slabs individually from the bottom of the stack to a breaking mechanism embodying rollers 18, 19, 20 and 22, which breaking mechanism severs the slabs into sticks 23 and feeds the sticks onto a stack 24. In the movements of the slabs from the stack 16 to the breaking mechanism, individual slabs are pushed from the bottom of the stack by a pusher ram 25 (Fig. 8) which ram moves the slabs in an arcuate path from the stack to a position for engagement by pusher elements 26 on a pusher-type chain conveyor 27, which latter pusher elements are driven linearly to move each slab along a linear path to the rollers 18 and 19 of the breaker mechanism. Rollers 18 and 19 grip the material of each slab and feed it to the rollers 20 and 22 which also grip the material. The rollers 20 and 22 are driven more rapidly than the rollers 18 and 19, so that the material of the slab, which is preferably scored axially of the rollers, is severed into sticks at a positionbetween the two pairs of rollers.

It may be readily understood that in the handling of relatively thin slabs of material, and particularly material which is relatively soft and flexible, such as chewing gum, some slabs may occasionally become damaged or bent, so that they will have a tendency to become jammed in the machine or may cause jamming in the subsequent machine which wraps the severed sticks. In the rapid operation of a machine of the type herein illustrated, the jamming of one damaged or bent slab will cause others to be jammed and will disrupt the proper operation of the machine until the damaged and jammed material is removed and the parts of the machine are cleared for operation. In order to minimize the waste of material and to conserve an operat-ors time in removing jammed material from the parts of the machine, it is essential that the machine shall be stopped as soon as any jamming of the material occurs or even when a piece of material is encountered which would be likely to jam in the machine if its motion progressed. It is for automatically eifecting such stoppage of a machine that I have devised the control mechanism which is herein disclosed.

For effective operation in association with the disclosed machine, my control mechanism embodies two parts which respectively embody switches 28 and 29, either of which serves as an instrumentality eifective to stop the material moving parts of the machine 15. Switch 29 is actuated by, and responsive to movements of a movably mounted member 30 (Figs. 2 to 5)., while the switch 28.

is actuated by, and responsive to movements of a mov ably supported member 32 (Figs. 6 to 10). In each instance, the movable members 30 and 32 span a portion of the path of movement of the material from'the stack 16 to thebreaking mechanism and are normally disposed in positions such that a normal workpiece or slab passes the movable member as it moves along the path, although a bent or damaged workpiece or slab will engage one or both of the movable members to move the member, thereby actuating the switch responsive to that member to effect stoppage of the machine.

Considering the machine and the parts of the mechanism in greater detail, as illustrated in the accompanying drawings, the hopper 17 has a back wall 33, end walls 34 and 35 and inwardly extending front flanges such as 36 at its opposite ends, which front flanges tend to keep the material in stacked relationship as it is placed in the hopper between the end walls through the open top of the hopper. As depicted in Figs. 6 and 8, the lower portions of the end walls 34 and 35 have front and rear edges such as 37 and 38 respectively which extend forwardly at an angle to the upper portions of the end wall edges, whereby, with the aid of a lower sloping back wall portion 39, the workpieces or slabs at the bottom of the stack 16 are diverted forwardly in gradually staggered relationship relative to the workpieces or slabs at the upper portion of the stack.

The supporting structure of the machine includes a base plate 40 (Figs. 6 and 8) which supports the bottom of the stack 16 and provides a surface over which workpieces or slabs from the bottom of the stack 16 are moved in a predetermined curved path by the action of the driven pusher ram 25. In the disclosed machine, the pusher ram 25 moves into the bottom of the hopper from the back and from a position such as that shown in Fig. 8 to push the bottom workpiece or slab from a position such as that depicted at 42 to a position such as that illustrated at 42a. In moving from the position at the bottom of the stack, as shown at 42, to the position in which it is removed from the stack, as at 42a, the bottom workpiece or slab passes under the movable member 32 to a position beneath the movable member 30,in which latter position the slab extends longitudinally of a rail 43 having a top surface in substantially coplanar relationship to the upper surface of the supporting plate 40.

As shown in Figs. 1 and 4, a workpiece or slab which has been moved from the stack by the pusher ram 25 so as to extend longitudinally of the rail 43 is aligned at one end, and extends longitudinally of the chain conveyor 27, so as to be engaged by pusher elements 26 on that chain conveyor which are driven in timed relationship to the movements of the pusher ram 25. The chain conveyor includes an operating chain 44 driven by a sprocket 45 and, except for the portion thereof which engages the sprocket 45, travels in a slot 46 between two coplanar guide plates 47 and 48. The pusher elements 26 are supported from the chain 44 and are driven thereby. The pusher elements 26 of the chain conveyor move each successive workpiece or slab into engagement with the rollers 18 and 19 of the breaking mechanism. Preterably these rollers are driven at surface speeds such that they draw an unbroken workpiece or slab away from the pusher element 26 which forces the workpiece or slab into contact with the rollers, thereby avoiding the tendency to bend or flex a slab as a result of its being moved by the pushing action of one of the pusher elements.

In the disclosed embodiment of my invention, the part of the control mechanism which includes the movably mounted member 30 and the switch 29 serves primarily to stop the operation of the machine as a result of flexure of, or damage to a workpiece or slab which is being moved by a pusher element of the chain conveyor 27, While the movable member 32 and the control switch 28 are disposed and arranged to effect stoppage of the ma-' chine when a bent ordamaged slab is moved by the pusher ram 25 or when, for any reason, a slab or workpiece is bent or damaged during its movement by the ram from the stack to a position from which it is moved by the chain conveyor.

As shown in Figs. 1 to 5, the movable member 30 constitutes an elongated bar 49 which extends longitudinally of the rail 43 and chain conveyor 27 in spaced and substantially parallel relationship to the rail and at a distance from the rail which affords clearance for free passage of a normal workpiece to a position between the rail and bar, as well as for free movement of the workpiece or slab along the rail by a pusher element of the chain conveyor. At the end near the rollers 18and 19 of the breaking mechanism, the bar 49 is hingedly supported for swinging movement in a plane lateral to the top supporting surface of the rail 43 by a cross pin 50 carried by an arm 52 from a frame member 53 of the machine. At the end of the bar 49 opposite the cross pin 50, a plate 54 (Figs. 1 and 2) is secured to the end of the bar by fastening means such as a screw 55, which plate has a foot 56 on its lower end, which foot rests against the upper surface of an extended end portion of the rail 43, so that the foot 56 serves as a fixed support for the movable end of the bar. The plate 54 also has a projection 57 thereon which normally engages a resilient actuating finger 58 on the switch 29 to hold the switch 29 in a circuit closing position. A handle 59 is secured to the upper portion of the movable end of the bar 49 to serve as a grip for the manual movement of th bar to and from its normal position.

.In order to provide for the retention of the bar in an elevated or out of the way position, when desired, a detent 60 is mounted in a bore 62 at the hingedly supported end of the bore and in alignment with the arm 52. A spring 63 mounted under the detent 60 in the bore 62 urges the detent outwardly from the bar and into contact with the end surface portion of the arm 52. As depicted in Figs. 3 and 5, a depression 64 is provided in the end surface portion of the arm 52 at a position for alignment with the detent 60 and for engagement thereby to retain the bar in an upright position wih respect to the operating parts of the machine.

Normally a workpiece or slab which is being moved by one of the pusher elements 26 passes freely beneath the surface of the bar while it is in its normal position with the foot 56 resting on the top of the rail 43. However, any abnormal upward flexure or deflection of a workpiece or part of a slab will bring the material of the workpiece into contact with the lower surface of the bar and raise the bar to an extent that the switch 29 will be opened. When the bar has been thus deflected to the extent that the opening of the switch 29 results, the driven pusher elements are stopped. The operator may then lift the elongated bar 49 to the out of the way position illustrated in dot-and-dash lines at 49a in Fig. 1 to facilitate the removal of the damaged or jammed workpiece. As depicted in Fig. 4, the bar 49 has a beveled marginal surface 65 facing toward the rail 43 and extending along the side of the bar from which the slabs or workpieces enter the space between the bar and the rail in order to insure freedom of movement of the workpieces or slabs into the space without being bent or deflected. Also, a beveled upper surface 66 extends longitudinally of the bar 49 to provide room, for the swinging movement of the movable member 32 when the bar 49 is in its normal position.

As may be observed by reference to Fig. l, the switches 28 and 29 are connected in series through lead wires 67, 68 and 69. The circuit through those series connected switches controls the operation of a circuit breaker which effects the starting and stopping of a prime mover, such 1 as an electric motor which drives the chain conveyor.

asaaso'r readily understood that both of switches 28 and 29 must be closed for normal operation of the machine, and the interruption of the circuit through either switch will stop the operation of the machine.

As shown in Figs. 6, 7, 8, 9 and 10, the movable member 32 is mounted for swinging movement relative to the axis of aligned screws 70 connecting side arm portions 72 and 73 of the movable member to opposite end walls 34 and 35 of the hopper. The lower end portions of the side arms 72 and 73 are connected together by an elongated bar 74 which spans the lower front portion of the hopper in spaced relationship to the base plate 40. T o establish the normal position of the bar 74, stop lugs such as 75 on the side arms 72 and 73 rest against stops such as 76 on the end walls of the hopper, and in such normal position, a lower surface 77 of the bar '74 is spaced from the base plate 40 to provide clearance for the free passage of a normal workpiece from the hopper and below the bar 74 when that workpiece is pushed from the hopper by the pusher ram 25. Fingers 78 extend upwardly from the bar 74 in spaced relationship longitudinally of the bar and have inner surfaces in opposed and substantially parallel relationship to the surface of the back wall portion 39 of the hopper to aid in keeping the workpieces in the lower portion of the hopper stacked in the desired staggered relationship to one another. It may be understood that the outward movement of an abnormal or damaged workpiece or slab from the hopper effects an outward swinging movement of the bar 74 and arm portions 72 and 73 of the movable member away from the hopper end walls by virtue of the engagement of the workpiece or slab with the bar 74 during such movement.

Above the axis of the aligned mounting screws 70, the arms 72 and 73 have upward extensions 79 and 80 thereon, which extensions are movably connected through links 82 and 83 to arms 84 and 85, which latter mentioned arms extend forwardly in spaced and substantially parallel relationship at opposite ends of the hopper from a shaft 86 which is journalled in bearings 87 and 88 on the back wall 33 of the hopper. Pins 89 and 90 at the opposite ends of each of the links 82 and 83 serve movably to connect those links to the arms 84 and 85 and to the upward extensions '79 and 80 on the movable vmember. With this arrangement of parts, upward swinging movement of the arm portions 72 and 73 away from the hopper eifects a corresponding downward swinging movement of the upper extensions 79 and 80, resultant movements of the links 82 and 83 and the arms 84 and 85 to produce a rotational movement of the shaft 86. The parts, of course, are each subject to movement in the revcrse directions.

A handle 92 is secured to the mid-portion of the shaft 86 by fastening means, such as a cross pin 93, and extends upwardly from the shaft to an accessible position above the hopper. A downwardly extending arm 94 on the handle 92 has angularly disposed end surfaces which are aligned for engagement with the peripheral surface of a roller 97 supported for rotation relative to a movable arm 98 by a cross pin 99. The movable arm 98 is supported for swinging movement on the back wall 33 of the hopper by a shaft 100 which is carried from the hopper back wall by a suitable channel type bracket 102. A leaf spring 103 having one end anchored to the channel bracket 102 through an auxiliary bracket 104 has its other end engaging the surface of the movable arm 98, resiliently to hold the roller 97 in a position for engagement with the angularly disposed end surfaces 95 and 96 of the arm 94 on the handle. A set screw supported by an auxiliary bracket 106 from the channel bracket 102 engages the mid-portion of the leaf spring 103 to provide for adjustment of the normal position and biasing force of the spring 103 against the arm 98. This spring, arm and roller mechanism serves as an adjustable and.

6 releasable retaining means for restraining the handle in a position in which the movable member 32 is in its normal position relative to the path of movement of the workpieces from the hopper.

In its normal operating position, as shown in Fig. 7, the handle 92 and the arm 94 thereon are releasably retained by engagement of the resiliently urged roller 97 with the angularly disposed end surface 96 on the arm to hold a surface 107 of the arm against a fixed stop 108 on the channel bracket 102. In this position, a bifurcated end surface portion 109 of the arm 94 engages a resilient actuating spring arm 110 on the switch 28 to hold the switch in a closed position. Release of the end surface 96 of the arm 94 from engagement'with the peripheral surface of the roller 97 may be eifected either by engagement of an abnormal or damaged workpiece with the bar 74 or by manual force applied to the handle 92. When thus released, the handle moves to a position such as that illustrated in dot-and-dash lines at 92a in Fig. 6, and is thus retained until manually restored to the normal position, because of the engagement of the end surface 95 on the arm 94 with the peripheral surface of the roller 97. When it is desired to retract the movable member 32 to an out of the way position, such as that illustrated in dot-and-dash lines at 3211 in Fig. 6, the handle is manually moved to the position indicated in dot-. and-dash lines at 92b. It may be understood that in either of the latter described released positions, the switch 28 is opened and the machine cannot operate.

From the foregoing description and reference to the accompanying drawings, it may be readily understood that I have provided an automatic control mechanism which is effective upon the movements of an abnormal or damaged workpiece in the course of movements of workpieces through a predetermined path in a machine to effect stoppage of the machine as soon as the presence of the abnormal or damaged workpiece is detected by a movable member which serves as a feeler element spanning a preselected portion of the path of movements of workpieces through the machine.

It is understood that the foregoing description is merely illustrative of a preferred embodiment of the invention, and that the scope of the invention therefore is not to be limited thereto, but is to be determined by the appended claim.

I claim:

In a control mechanism for use on a machine in which workpieces are pushed along a supporting surface in a path, the combination comprising a member supported for swinging movements in a plane lateral to the supporting surface from and toward a normal position in which a portion of said member spans said path and is spaced from the supporting surface to provide a predetermined small clearance between the supporting surface and said portion of the member for the passage 7 of normal workpieces along the path, said member being movable from said normal position by engagement with an abnormal workpiece as it is pushed along the path, means tending to hold the member in said normal position, means actuated by movement of the member from the normal position for effecting stoppage of movement of workpieces along the path, said means tending to hold 9 the member in said normal position comprising a lever mounted for swinging movement, a spring biased roller engaging the lever releasably to hold the lever against a fixed stop, and links connecting said member to the lever.

References Cited in the file of this patent UNITED STATES PATENTS 1,149,018 Beregh Aug. 3, 1915 1,218,988 Droitcour Mar. 13, 1917 1,642,422 Manofsky Sept. 13, 1927 1,673,222 Bonebrake June 12, 1928 1,738,103 Haman et a1. Dec. 3, 1929

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