US3008706A - Signature collator - Google Patents

Description

Nov. 14, 1961 Filed July 51. 1956 Liri:

C. H. HEIGL ET AL SIGNATURE COLLATOR 4 Sheets-Sheet l NOV. 14, 1961 C, H, HEIGL ET AL 3,008,706

SIGNATURE COLLATOR Filed July 5l, 1956 4 Sheets-Sheet 2 :5 Ipg I" if Nov. 14,` 1961 Filed July 5l, 1956 c. H. HEIGL ET AL 3,008,706

SIGNATURE COLLATOR 4 Sheets-Sheet 5 INVENTORJ` 24k/ H. M15/6.4

BY V/c w@ ,4. Zaai-Z N0v.14,1961 C. H. HEIGL ETAL 3,008,706

SIGNATURE COLLATOR Filed July 31,*1956 4 Sheets-Sheet 4 United States Patent Office Patented Nov. 14, 1961 3,008,706 SIGNATURE COLLATOR Carl H. Heigl, Cleveland, and Victor A. Zugel, Parma,

Ohio, assignors, by mesne assignments, to Harris-Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed July 31, 1956, Ser. No. 601,256 13 Claims. (Cl. 270-56) This invention relates to improvements in signature collators, that is to say, collators for collecting a series of paper items each of which has more than one sheet or page. One of the uses for such collators is the collecting of a series of signatures to be used in the making up of a book, but multipage or multisheet units other than signatures may be collected by such machine, and indeed the machine may be used for collecting single sheet items on occasion.

According to the present invention the feed is from the bottom of each pile of signatures. The piles may therefore be renewed from the top without interrupting the operation of the machine.

One of the objects of the invention is the provision of novel and effective means for feeding signatures from the bottom of a pile.

Another object is the provision of novel mechanism Ifor causing mechanical grippers to close at one end of an oscillation of the gripper carrier and to open at the opposite end of the oscillation.

Another object is the provision of mechanism of the character stated wherein the means for closing and opening the grippers is operated by an impeller loose on the shaft to which the gripper carrier is keyed.

Another object of the invention is the provision of automatic means for stopping the operation of the collator whenever there is a failure to feed a signature at one of the stations, the said automatic means functioning also to indicate by a light signal the station in which the failure occurred, and a single manual control at each station serving to extinguish the light signal and at the same time to restart the whole machine.

Other objects and -features of novelty will appear as we proceed wi-th the description of that embodiment of the invention which, for the pur-poses of the present application, we have illustrated in the accompanying drawings, in

which j l FIG. 1 is a side elevational view, partly in vertical section, of one of the stations of a collator embodying the invention, certain portions of the driving and operating mechanism being included, the position of the view being indicated by the line 1-1 of FIG. 2;

FIG. 2 is an elevational view, partly in vertical section along the line 2--2 of FIG. l;

FIG. 3 is a detail view partly in vertical section along the line 3-'3 of FIG. 2;

FIG. 4 is a similar view along the line 4-4 of FIG. 2;

FIG. 5 isa vertical sectional view taken substantially on the line 5-5 of FIG. 2; illustrating the drive for the principal oscillating shaft of the machine;

FIGS. 6 and 7 are lfragmental views illustrating the trigger mechanism for actuating one of the switches disposed at each station of the collator for stopping the machine when there is a failure to feed -a signature in that station; FIG. 6 showing the normal condition with a signature in position and FIG. 7 showing the switch operating because of the absence of a signature;

FIG. 8 is a fragmental perspective view with one oscillating disc removed to more clearly illustrate certain features of the invention, and

FIG. 9 is a wiring diagram.

The machine of the invention comprises a drive shaft being rotated continuously by an electric motor, not shown, but indicated at 11 in FIG. 9. Upon this shaft there is keyed eccentrically a circular disk 12 upon which a ring 13 bears, the ring being held against axial movement by a pair of straps 14 screwed to the disk. Integral with the ring there is a connecting rod 15 which is pivoted at its upper end to a bifurcated crank 116 that is keyed to an intermediate oscillating shaft 17 which carries a large gear v18. The connecting rod 15 land crank 16 produce oscillations of shaft 17 and gear 18` through a relatively small arc.

Large gear 18 meshes with a pinion 19 that is keyed to the principal oscillating shaft 20 which extends through the entire length of the collator. Because of the gearing ratio between gears 18 and 19 oscillations are produced in Shaft 20 extending through a considerable angle, which in practice is about In the case of a relatively long machine, incorporating perhaps 25 stations, the drive from shaft 10 through shaft 17 to shaft 20 may be duplicated at intervals to eliminate some of the torsional effect upon shaft 20.

At each station there are two spaced disks 21 with split hubs that are clamped to the shaft 20 by bolts 22. Their positions therefore can be readily adjusted angularly and axially. Between the disks 21 of each pair there is secured a block 23 which is of U-shape. It has an outer portion 24 which bridges the space between the disks and a pair of side walls 25 which are fastened to the disks by bolts 26 or the like projecting through holes 26 in the block. In each side wall 25 there is an opening or window 27 which registers with a similar window in the adjacent disk 21.

Mechanical grippers 29 are mounted on the outer ends of rods 30 which extend loosely through radial holes in the bridging part 24 of the block 23. The inner ends of these rods have slide bearings 30 projecting towards each other from the inner ends of the side walls 25. Intermediate their upper and lower bearings the rods are joined by a transverse cylindrical bar 31 upon which is mounted to revolve a wheel or follower 32. Coil springs 33 surrounding the rods 30 and bearing on the bridging portion 24 of the block and on the ycylinder bar 31 tend to close grippers 29 and press inwardly the bar 31 and the follower 32.

Mounted loosely upon the shaft 20`-between the disks v21 of each station there is a part which, for lack of a better word, We term an impeller 35. It comprises a sleeve surrounding the shaft and fitting it accurately but not tightly. Between the ends of the sleeve and the sides of the adjacent disks are washers 36 capable of independent rotation or oscillation. As an integral part of the impeller there is a rib 37 extending part way around the impeller and having two abutments 318 and '39, the purpose of which will presently appear. On the rib 37 there is secured by bolts 43, a hardened steel plate 40 which on its outer edge is formed with a shallow cavity 41 and a deep cavity 42 side-by-side, each of these cavities having curvature such as to receive the follower wheel 32.

On round bars 44 and 45 -ixed in the machine frame there is mounted at each station a bracket 46 in which are carried adjustable stops 47 and 48vthat may be secured in adjusted position by lock nuts 49. Stop 47 is so disposed as to contact abutment 38 when the shaft '20 reaches the end of its oscillation in the clockwise direction as viewed in FIG. l. Stop 48 is so disposed that abutment 39 strikes it at the end of the oscillation in the counterclockwise direction, this position of the impeller being indicated in broken lines in FIG. l.

v When a signature has been delivered the grippers are open .and the follower wheel 32 is resting in the shallow cavity 41. The clockwise oscillation now begins. As

3 soon as the abutment 38 strikes st-op 47 to clockwise oscillation of the impeller is suddenly interrupted, the disks 21 and block 23 are driven somewhat farther by the gears 18, 19, and as a result the follower wheel 32 is snapped out of `contact with the shallow cavity 41 into the space within the deep -cavity 42. TheV springs 33 are then free to pull down the rods 30 and the grippers 29 thereon to grip a signature S then in position on the outer end portion 2.4 of block 23, as will be explained more particularly hereinafter. With a signature in the grasp of the grippers counterclockwise oscillation now begins. As soon as the block 23 with its grippers reaches a position approximately as shown` in broken lines in FIG. l, abutment 39 on the impeller strikes stop 48 interrupting its counterclockwise oscillation-while the block travels slightly farther and thus causes the follower 32 to ride out of the deep cavity 42 into the shallow cavity 41, thus moving the grippers outwardly, which releases their hold upon the signature.

At each station there is a hopper 50, the sides and back of which are adjustable so as to accommodate signatures of different dimensions. At the front side `of each hopper there is a fixed plate 51 and a liexible plate 52. The latter plate is mounted at its upper end by screws or the like 53, while its lower end is flexed more or less by an adjustable screw or screws 54. The flexed plate 52 in combination with the other walls of the hopper tend to retain the signatures S in place, that is, all but a few of the lowermost ones. A hopper base 55 extends forward from the rear of the hopper and at its forward extremity about midway between the front and` back walls of the hopper there is a roller 56. The base 55 and roller 56 tend to support the lowermost signatures, the front edges of which have dropped olf the exed plate 52.

A sucker S8 mounted on an arm 59 is clamped to a hollow shaft 60 running the length of the machine in which suction is induced by any suitable means and is controlled by suitable valve means, not shown, to be effective for a portion ofk each cycle. The sucker 58 at each station is a telescoping sucker. It is disposed in a transverse plane midway between theV grippers 29, and is cleared by a recess 28 in the block when the parts are in the position of FIG. 1. At each station a connection 61, which may include a valve, is joined with the lower end of the sucker by a flexible conductor 62. The sucker comprises a cylindery and a piston which is normally extended by a spring, not shown. Assoon as the sucker rises bodily, far enough to contact the bottom sheet itis sealed by the sheet, whereupon the suction quickly draws the piston downwardly against the action of the spring, telescoping the sucker and lowering the forward edgeV of the sheetinto engagement with the top 24 of block 23 inposition to enable the. mechanical grippers to grasp it. Thereafter the suction is relieved.

As soon as the sucker 58 ldescends far enoughto be out of the waya pair of flexible fingers 64 that. are normally in the dotted line position of FIG. 1 swing backward to the full line position ofv that gure to support the lowermost signaturesabove the bottom one that is then in the grip of the sucker.

These fingers are carried upon arms 65 that are fastened toarock shaft 66 Vsuitably mounted in frame members of the machine.- Angular and axial adjustment of these arms may be provided by mounting them on shaft 66 by meansI of expansible clamps. having tightening screws 67,

The oscillations of shafts 60 and 66 are effected by means of cams on the constantly rotatingY shaft 10. The sucker` operating cam may be a box cam 68 illustrated in FIGS.- 2 and 4, in whichk a roller follower 69 runs, the follower being carried upon a lever 70.which is mounted to pivot about a rod 71 fixed in the machine frame. From the freeend of lever 70 a connecting rod 63 extends upwardly to the outer end of a crank 73 that is secured to the oscillating shaft 60. In FIG. 4 the parts are shown after the sucker has descended to its lowest point where it remains for a period of the order of Thereafter the cam groove issuch that the sucker rises to grip a signature and then descends to bring the signature down to a position where it may be grasped by the grippers, after which suctions interrupted` and the sucker descends to resume the. lowered position illustrated in FIG. 4.

A second box cam 75 mounted upon theshaft 1.0 has a groove in which runs a roller follower 76 that-is .mounted upon a lever 77 which is arranged to pivot about the same rod 71 upon which the lever 70 pivots. To the free end of lever 77 an upwardly extending connecting rod 78 is joined and this rod is pivotally connected at its upper end to-a crank 79 that is clamped to-the rock shaft 66 by which the lifting fingers 64 are carried, as-

previously described. In FIG. 3 the outer concentric part of the cam grooveis in engagement with the follower 76. Duri-ng an interval of dwell of about 110 while the follower runs in the outer concentric part of the groove the fingersY 64 engage and support the lowermost signatures labove the one being withdrawn. Thereafter the cam groove depresses the follower and causes the fingers to swing outwardly in which position they remain during a substantial interval of about when the groove again raises the follower 76 to substantially the position of FIG. 3, thereby swinging theA fingers backwardly to signature supporting position.

In accordance with the invention automatic control means is provided to stop the entire machine whenever a signature is missing at one of the stations at the time the signatures should be fed forward. FIGS. 6 and 7 illustrate the trigger means for accomplishin-g this purpose. On the outer side of one of the disks 21 of each pair there is mounted about a pivot {it} a trigger 81 which is overbalanced in such manner that it tends to assume the position of FIG. 7 where itsvmotion is limited by a stop 82 that is fixed to the same disk 21. As cach signature Sis pulled down by the sucker 58 and grasped by the grippers` 29 it engages the short end of trigger 81 and tilts itdown to the position illustrated in FIG. 6 out of the way of an arrn 84 that is secured to a small shaft 83 whichextends into Ithe box or casing 86 of a switch that is lixedly. mounted` in the machine adjacent and somewhatv above the trigger 81. Within theA box 86 a second arm 85 is fixed upon shaft 83. When swung up clockwise a small amount, arm 85 engages a button-87 which through suitable electricalconnections illuminates a signal light or lamp 88 andk at the same time breaks a circ-uit to the motor 11. The action of this switch is indicated in FIG. 9, where the arm 85 is shown in its normal position in which it completes a circuit from line` wires L and L" through motor 11-. One of these switches `with its trigger mechanism isprovided at each station. If" nosignature is in place over the block 23 at the proper time in the cycle the corresponding trigger- 81, by the action of gravity, takes the position of FIG. 7 where its rearwardfend is backed. by` stop 82, and4 its forward end can strike arm 84, which it does as the disks 21 turn counterclockwise. ArmrSS-is thereby thrownup to break the circuit through motor 11 and at the same time to complete acircuit through signal lamp 88,V FIG; 9. The switch mechanism will remain in this position. The operator is apprized by the light signal as to whichone of the numerous stations is the one where the misfeedV occurred. He can. then correct the difiiculty, making sure that the pack of signatures at they station in` question is complete, after which hel may depress a manual. button 89 which will return arms 85 and 84'to their normalvposition, extinguish signal,

lamp 88 andv complete the circuit through motor 11. Motor 11 drives the shaft 20. which. not onlyI oscillates the disks 21. and operates .the grippers 2.9, but through cams 68 and 75 oscillates shafts 60 and 66 for movingy the stickers 58 of the various stations up and down and for swinging the lifting fingers 64 of the various stations in and out'.

The electrical conductors for the various micro-switches and signal lamps may be accommodated by a metal tube 95 extending through substantially the full length of the machine and preferably furnishing part of the support for the boxes 86.

In FIG. 1 there is shown a conveyor trough 90' constituted partly by a separate plate 91. The partial packs o-f signatures at the various stations are moved along intermittently by an endless chain 93 carrying spaced pusher bars 92 which extend through the space between trough 90 and plate 91 and serve to advance the various packs intermittently after a signature is dropped into the trough at each station. Mechanism for accomplishing this purpose is well known in the art and ltherefore requires no detail description.

Operation-After the hoppers 50 at all stations are loaded with signatures the shaft should 4be inched around counterclockwise until the blocks 23 are in their down position indicated in broken lines in FIG. 1. The motor may then be started. Clockwise oscillation of the disks 21 will then begin. Before they reach the full line position of FIG. 1 the suckers 58 will rise and grasp the bottom signature of each pile and pull its forward edge down against the block 23, after which the fingers 64 will swing back to support the signatures which have dropped off the flexible plate 52. As the disks 21 approach the full line position of FIG. 1 the abutment 38 on the impeller will strike the stop 47 and the roller follower 32 will snap into the deep cavity 42, causing the grippers 29 to grasp the signature. Immediately thereafter the suction in suckers 57 will be broken and those suckers will descend to the full line position of FIG. 1. Then the oscillation of the pinion 19 in a coun-terclockwise direction will begin and will oscillate the disks 21 counterclockwise. Lifting fingers 64 may now be retracted to the dotted line position of FIG. l. Roller follower 32 will remain in the deep cavity 42 and the springs 33 will continue to hold the grippers closed as the signature moves down over the disks 21. As the grippers approach the dotted line position of FIG. 1 the signature will Ybe intercepted by fingers 96 laterally outward from the disks 21 as shown in FIG. 8 and will be guided down into trough 90. Abutment 39 will then strike stop 48, causing the roller follower 32 to move out of the deep cavity 42 into the shallow cavity 41, which will compress springs 33 and move rods 30 with their grippers 29 outwardly to release the signature.

From time to time the operator must replenish the signatures in the various piles by dropping fresh signatures into the hopper from above. The machine can continue to function continuously unless at some station the sucker 58 fails to pull down the bottom sheet or the grippers 29 fail to grasp it. In such event the trigger means previously described will stop the whole machine and the signal lamp for that station will be illuminated to guide the opera-tor to the point of failure.

Having thus described our invention, we claim:

l. In a bottom-feed signature feeder, an oscillating shaft, a support *member connected to said shaft for oscillation therewith, a gripper pad on said support member, a gripper mounted in said support member for movement toward and from said pad, a spring for moving said gripper inwardly toward said pad, `an impeller free to rotate on said shaft and havingdeep and shallow peripheral cavities side by side in a plane transverse to said shaft, a follower carried by said support member operatively connected with saidY gripper, said follower eng-aging said shallow. cavity for raising the gripper in opposition to spring pressure and'engaging said deep cavity for enabling spring pressure to close the gripper, fixed abutments for contact with said impeller at the ends of the oscillation of said shaft to shift the impeller from engagement of one of its cavities with said follower and cause engagement of its .other cavity with the follower, whereby the gripper is `closed at one end of theoscillation to take a signature and opened at the other end to release a signature.

2. A signature feeder as defined in claim 1, wherein one abutment shifts said impeller to cause said follower to drop into said deep cavity while the gripper is in a position to grip a signature, and wherein the other abutment shifts the impeller to cause said follower to move from said deep cavity into said shallow cavity while the grip per is in a position where the signature is to be released, whereby the gripper is moved outwardly to release the said signature..

3. In a bottom-feed signature feeder, an oscillating shaft, a pair of spaced disks keyed to said shaft, a block bridged across the space between said disks and fastened to the disks, a gripper pad on said block, a gripper mounted in said block, spring means for urging said gripper inwardly -into engagement with said pad, an impeller loose on the shaft between said disks, said impelk1er having deep and shallow peripheral cavities side by side in a plane transverse to said shaft, a follower carried by said block operatively connected with said grip per engaging said shallow cavity for raising the .gripper in opposition to said spring and engaging said deep cavity for enabling said spring to close the gripper, a fixed' abutment for stopping the impeller at one end of its oscillation .and causing the follower to shift from the shallow cavity to the deep cavity and enabling the spring to close the gripper, and a second abutment for stopping the impeller at the other end of its oscillation and causing the follower to shift back into engagement with the shallow cavity for opening the gripper.

4. A bottom-feed signature feeder las defined in claim 3, wherein there are two spaced-apart pads carried by said block and two spring-pressed grippers operatively connected with said follower for actuation thereby and by said spring, and sucker means disposed parti-ally between said grippers and oscillatable up and down for taking the lowermost signature of a pile of signatures and pulling its front edge down into position between said pads prior to the closing of the grippers.

5. In a bottom-feed signature feeder, a block carrying a pad, a mounting for said block, means for oscillating said mounting back and forth through an arc of not more than a radially disposed gripper mounted in said block, means for causing the gripper to close at its top position of. oscillation when the front edge of a signature enters the space between the gripper and the pad, an electric switch disposed above said mounting, a trigger pivotally carried by said mounting tending to move outwardly by gravity action when the gripper is in itS top position but normally held against such movement by the lower surface of 4a signature in the grasp of the gripper, an arm projecting downwardly from said yswitch in position to rock said trigger freely when the mounting moves upwardly toward its top position, and abutment means on said mounting to hold said trigger in position for causing it to tilt said arm to open the switch when the mounting moves in the opposite direction and no signature is present, and an electric connection from said switch to stop the feeder when said switch is actuated by said trigger.

6. In a bottom-feed signature feeder as defined in claim 5, an electric signal device, and means for energizing sai-d device when said switch is actuated by said trigger.

7. A collator for paper signatures, a series of stations each having mechanism comprising an oscillating vertical disk for takingsignatures from a pile and depositing them upon a conveyor, an oscillating shaft extending through said stations and fixed to said disks, a block on each disk moving with said shaft, a gripper pad on each block, a gripper mounted in each block movable inwardly under spring pressure toward the corresponding pad, mechanism for causing the gripper in each station to close on a signature at the top of its oscillation and carry -it forward to the conveyer upon movement of the respective block toward said conveyor, an electric switch disposed at each station, a trigger pivotally mounted on each disk tending to move outwardly by gravity action when the gripper on the corresponding block is at its top position but no-rmally held against such movement by the lower surface of a signature in the `grasp of the gripper on the block, an arm projecting downwardly from each of said' switches in position to rock the corresponding trigger freely when the latter moves upwardly toward the top position, and abutment means on each of said disks for holding the corresponding trigger in position to cause it to tilt said arm to open the corresponding switch when the disk supporting the trigger moves in the opposite direction and no signature is present on the corresponding block, electrical means set in operation by the actuation of -any of said switches for interrupting the oscillation of said shaft, an electric signal for each station actuated when the oorresponding switch is actuated, and manual means for resetting said switches.

8. In a signature feeding mechanism, a member movable between sheet receiving and delivery stations, a gripper carried by said member and movable relative thereto between open and closed positions, a cam follower operatively connected to said gripper, a cam cooperating with said follower and carried by said member and movable relative to said member between iirst and second positions respectively for opening and closing said gripper and maintaining said -gripper inthe respective position, and actuating means for said `cam comprising a iirst abutment disposed to strike said cam -upon movement of said member to said receiving station to actuate the latter to its said second position with respect to said member and a second abutment ydisposed adjacent said delivery station for striking said cam upon movement of the member to the delivery station to actuate the cam to its first said position with respect to said member.

'9. In a mechanism including a member reciprocated between limit positions along a predetermined path and having gripper means thereon for gripping a sheet at a iirst limit position to secure the sheet in a sheet position on said member and to effect movement of the sheet with said member along said path away from said iirst limit position, a sheet in said sheet position `having :a first side adjacent said member and an outer side facing outwardly of said member, said mechanism comprising a finger carried by said member adjacent said sheet position and held in a first position by the engagement thereof with the said iirst side of a sheet in said gripper means, means supporting said finger for movement yfromits said first position to a second position extending outwardly of said sheet position and of said member and including means for limiting the outward movement of said nger to said second position, a sensing station adjacent said path, said nger being biased to its said second position to yextend outwardly of said sheet position as it moves by said station in the absence of a sheet gripped by said gripper means, and sensing means responsive to said `finger `as it passes said station when in its said second position and moving away from said iirst limit position for effecting a control operation affecting said mechanism, said sensing means comprising a switch actuating arm disposed in the path of said linger when in its said second position and means on said arm and finger providing a one-Way actuating connection for said arm which .is responsive only to movement of said finger away from said first limit position to effect said control operation.

10. In `a mechanism, the structure as defined in claim 9 wherein said means supporting said nger comprises a pivot pin and said finger isbalanced to move under the influence of gravity about said pivot pin to its said second position in the absence of a sheet in said gripper means.

11. In a sheet handling mechanism, a sheet carrier member oscillatable about an axis between a pickup station and a delivery station, sheet-gripping means operable between open and closed positions, an oscillatable cam member supported vcoaxially with said carrier member and rotatable about the axis of oscillation relative .to said carrier member, a cam follower on said carrier member urged into engagement with said cam member to lcause Vrotation of said cam member with said carrier member,

stop means at said delivery station and at said pickup station engageable with said cam member upon oscillation of said carrier member to the respective station to shift said cam member relative to said carrier member withsthe stop means at the respective stations shifting said cam member in respective directions opposite to each other whereby said cam member is oscillated between rst and second positions relative to said carrier member by movement of said carrier member between said delivery and pickup stations, said cam member having cam surfaces providing different displacements for said cam follower for the said two positions of said cam member, and means connecting said follower to said gripping means to open the latter when said cam member is actuated at said delivery station and to close the latter when said cam member is actuated at the pickup station.

12. In a sheet handling mechanism as denedfin claim 1l wherein said follower is supported by said carrier member for movement radially of the axis of oscillation and said gripper means comprises a sheet gripper and a stem supporting said gripper for movement radially of said axis, said stem being connected to said cam follower, and a spring acting on said stem and urging said cam follower into engagement with said cam member.

13. A collator for paper signatures, a series of stations each having mechanism comp-rising an oscillating vertical disk for taking signatures from a pile and depositing them upon a conveyor, as oscillating shaft extending through said stations and iixed to each disk, a block connected to each disk and moving with said shaft, a gripper pad on each block, a gripper mounted in each block and movable inwardly under spring pressure toward the corresponding pad, mechanism for causing the gripperin each station to close on a signature at the top of its oscillation yand carry it forward to the conveyor, an electric switch disposed at each station, a trigger pivotally mounted on the disk tending to move outwardly by gravity action when the gripper is at its top position but normally held against such movement by the lower surface of a signature in the grasp of the `gripper associated with the corresponding block, an arm projecting downwardly from each switch and in position to be engaged by the corresponding one of said triggers when the latter yis extended to actuate the switch, each of said triggers and said corresponding arms including means providing a oneway actuating connection effective to move the correspending arm to actuate the corresponding switch only when the corresponding disk is oscillated to move the corresponding trigger downwardly toward the conveyor, electrical means set 4in operation by the actuation of any of said switches for interrupting the oscillation of said shaft, an electric signal for each station actuated when the corresponding switch is actuated, and manual means for resetting said switches.

References Cited in the iile of this patent UNITED STATES PATENTS 1,108,220 Pancoast Aug. 25, 1914 1,194,012 Grimmer Aug. 8, .1916 1,367,331 Tauscher Feb. 1, 1921 1,575,891 Ashby Mar. 9, 1926 1,948,038 Kast Feb. 20, 1934 2,020,321 Kleineberg Nov. 12, 1935 2,082,064 Kleineberg June 1, 1937 2,166,709 Swanson July 18, 1939 2,331,533 Bishop Oct. 12, 1943 2,470,557 Herrmann May 17, 1949 2,568,604 Bechberger Sept. 18, 1951 2,637,552 Watson May 5, 1953 2,711,896 Kleineberg June 28, 1955 2,791,421 Schramm .May 7, '1957 2,801,846 Stootho et al. Aug. 6, 1957

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