US2199743A - Guard for paper cutters - Google Patents

Description

y 7, 1940- w. c. EICKMAN 2,199,743

GUARD FOR PAPER CUTTERS Filed Dec. 21, 1938 2 Sheets-Sheet l l I l I l l l tit-2-- hm 75c 61 [Pat/v19 ATTOR INVENTOR.

May 7, 1940.

w. c. EICKMAN 1 9,743

Filed Dec. 21, l938 2 S eeee s-Sheet 2 INVENTOR- MLTEe G fiat/V19 ATTORNEYS UNITED STATES PATENT OFFICE Patented May 7, 1940 GUARD FOR PAPER'CUTTEBS Walter G. Eickman, Dayton, Ohio, assignor to Harris-Seybold-Potter Company,

Cleveland,

Ohio, a corporation of Delaware Application December 21, 1938, Serial No. 246,965

13 Claims.

- This invention relates to safety devices, and more particularly to a safety device or guard of the automatic type for use on a paper cutter or other machine, having a reciprocating work cutting or clamping element, or both, for protecting the machine operator against personal injury by such element or elements.

. An object of my invention is to provide an improved guard device of this character which is of relatively simple and economical construction but which is efficient and reliable in operation and can be readily applied to a paper outter or other machine of the type mentioned.

Another object is to provide a guard device whose action is very rapidly extensible so as to project itself into protective position prior to cutting or clamping of the work pile, which is a highly desirable improvement over previously built guards which advance only in direct proportion to the knife travel.

A further object is the provision of a guard which,in the retracted position, allows an unobstructed working zone and which, in-the extended position, allows any work piles to be undisturbed but yet effectively prevents the operators hands from being injured by the knife or clamp.

Yet another object of my invention is to provide an improved guard device, of the character mentioned, in which a novel arrangement of crossed links is utilized for causing automatic actuation of the guard element.

A still further object of my invention is to provide an improved guard device, of the character referred to, having a guard element arranged for. positive actuation by expansible and retractable linkage and in which means adapted to be actuated in response to travel of the movable element of the machine has a push-pull connection with the linkage.

My invention may be further briefly summarized as consisting in certain novel combinations and arrangements of parts hereinafter described and particularly set out in the appended claims.

In the accompanying sheets of drawings,

Fig. 1 is a partial side view of a paper cutting machine having the guard device of myinvention applied thereto, showing the device partly in section and in its extended position; v

Fig. 2 is another such partial side view of the machine showing the guard in its retracted position;

Fig. 3 is a partial sectional plan view taken through the guard device as indicated by line 3,-3 of Fig. 2;

Fig. 4 is a plan view of the front portionof a paper cutting machine with my guard device thereon and shown in its extended position;

Fig. 5 is a partial plan view similar to that'of Fig. 4, but showing the guard device in its retracted position; and I Fig. 6 is a partial front elevation looking in the direction indicated by line 66 of Fig. 4 and showing the thrust member or actuating cam.

Detailed reference will now be made to the drawings for the purpose of more fully describing the construction and operation of the embodiment of my invention illustrated therein. It should be understood, however, that although the drawings illustrate but one embodiment, the invention may be incorporated in various. other similar devices and apparatus.

My guard device may be appliedtovarious kinds of cutting or fabricating machines of the type having a reciprocating element and when applied to such machines, functions automatically to push the operator away from the .moving element so as to prevent him fr om being injured thereby. By way of exampla'thedrawings show a paper cutting machine Ill having my automatically operating guard device ll applied thereto, This machine has an upright frame 12 with a forwardly projectingwork support or table l3 thereon and an element [4 reciprocable in the frame for actuating the cuttingknife or shear blade l5. The machine may also have aclamp ing element [50. reciprocable in the frame for applying pressure to the work pile.

The guard device itself may comprise a su port ll extending laterally across the front of the machine a suitable distance above the table l3 and a movable guard element 18 also extending laterally across the front of the machine and connected with the support by means 01' extensible and retractable linkage IS. The support I! may be a bar of channel-like cross section, having its ends connected with the frame l2 adjacent the sides thereof by suitable connecting means, such as the brackets 20. The guard element I8 may be of any appropriate form, such asthe laterally extending bar shown in thisinstance.

The linkage l9'may comprise a pair of crossed links 2| and 22 which have their inner ends pivotallyconnected with the support I'l as by means of the pivot pins 23 and their outer ends pivotally and slidably connected with the guard element l8 as by means of pivot pins 24 extending through longitudinal slots 25 of the guard element. The links 2 l and 22 may consist of a single at the outer end of the linkage may straddle the guard element l8.

For actuating the linkage M to thereby project or retract the guard element i8, I provide suitable actuating means which may comprise a plunger 21 extending transversely of the support H and a thrust element or cam 28 connected with the movable element [4 of the machine I 8. Suitable bearing means may be provided on the support I! for mounting the plunger 21 thereon. For example, the support may be provided with an enlargement 29 having a bore in which the plunger 21 is slidable.

The outer end of the plunger 21 has a push-pull connection with the linkage l9 so that the guard element l8 may be extended or retracted by corresponding outward and inward movements imparted to the plunger. This connection between the plunger and the linkage may be formed by providing the links 2! and 221 with slots 30 adjacent their point of crossing and providing the plunger with a transverse pin 3| which extends through such slots of the links. The inner end of the plunger may be rounded and hardened and thus adapted for engagement by the thrust element or cam 28.

This cam may comprise a suitably shaped and constructed metal member which is mounted on the machine element It to project forwardly therefrom. The cam may have a relatively steeply inclined portion 32 for initial engagement with the plunger 21 to cause extension of the linkage as the knife l5 starts its downward travel and a relatively fiat or slightly inclined holding portion 33 for maintaining the linkage extended while the knife completes its stroke; When the movement of the machine element I4 is simply a reciprocating movement in a vertical plane, the cam 28 is mounted thereon so as to extend upright, but when the machine element has a combined vertical and lateral movement, as is common in certain paper cutters and other machines, the cam may be mounted with its longitudinal axis relatively inclined, as shown in Fig. 6.

For retracting the linkage and the guard element, I provide a retracting spring 35 which also acts to hold the plunger 21 in a position to be engaged by the cam 28. If desired, the plunger 2'! may be hollow and slotted, as shown in Figs. 2 and 3, and the retracting spring 35 may be located therein. One end of the spring bears against the inner end of the plunger recess and the other end of the spring bears against a spring seatwhich maybe in the form of a bar 38 extending through the slot of the plunger and connected with the support IT.

From the construction and arrangement of my guard device, as above described, it will be seen that when the machine element 14 and the knife l5 mounted thereon move downwardly, or downwardly and laterally as the case may be, the cam 28 will engage the plunger 27 and push the same outwardly. By reason of the leverage ratio of the link arms and the steeply inclinedcam surface, a small movement of element i l will cause the linkage l to be very rapidly extended to the position shown in Fig. l, thereby causing the guard element l8 to engage the operators arms adjacent or above the elbows with the result that his forearms and hands are drawn away from the knife and clamp before the latter elements act upon the work pile. My safety device is preferably so constructed and arranged that when in its extended position, as shown in Figs. 1 and 4 the guard element i8 will be at a greater distance from the knife i5 than the length of a mans forearm. The guard is held in this extended position while the knife completes its downward stroke. When the machine element I4 is lifted, the plunger 21 rides down off of the cam 28 and the spring 35 retracts the linkage and guard element E8 to the position shown in Fig. 5.

It will be noted that the support i7 and the linkage iii are arranged on the frame 52 so that the linkage extends downwardly as well as forwardly, as is clearly indicated in Fig. 1. By reason of this relative arrangement I find that the guard element will be further removed from the table is when in its retracted position so as to allow the working space below to be unobstructed, and when it is extended downwardly and forwardly, its vertical clearance above the table will be slightly greater than the height of the work pile. Thus, in instances where .a small pile is being cut in the center portion of the table with open spaces to either side thereof creating danger zones for the operators hands, the guard in moving to its extended position will not disturb the pile but will nevertheless sweep against the arms of the operator, effectively removing his hands from said danger zone.

From the foregoing description and the accompanying drawings, it will now be readily seen that I have provided an improved automatically operating guard device for paper cutters and other machines having a reciprocating element. It will be seen furthermore that this guard device, although of simple and economical construction, will be positive and reliable in operation and will effectively push the operator back away from the knife on each downward stroke of the machine element. The improved linkage arrangement of my guard device provides for an extensive rapid movement of the guard element in a downward and forward direction and the push-pull actuating means cooperating with the linkage insures a smooth and positive actuation of the device.

While I have illustrated and described my guard device in a somewhat detailed manner, it will be understood, of course, that I do not wish to be limited to the precise arrangement of parts and details of construction herein disclosed, but regard my invention as including such changes and modifications as do not constitute a departure from the spirit of the invention and the scope of the appended claims.

Having thus described my invention, I claim:

1. In a guard device for a machine having a frame and a reciprocating part, a support mounted on the frame, a movable guard element in front of said reciprocating part, a pair of crossed links, a pivotal connection between said links at their intersection, a pivotal connection between one end of each link and said support and between the opposite end of each link and said guard element, one pivotal connection for each link having a fixed axis and the other two pivotal connections having movable axes, and

means actuated upon the movement of said reciprocating part for imparting movement to said links.

2. In a guard device for a machine having a frame and a reciprocating part, a thrust member connected with said reciprocating part for movement thereby, a support mounted on the frame, a movable guard element in front of said reciprocating part, a pair of crossed links, a pivotal connection between said links at their intersection, a pivotal connection between one end of each link and the said support and between the opposite end of each link and said guard element, one pivotal connection for each link having a fixed axis and the other two pivotal connections having movable axes, and means arranged to be engaged by said thrust member'to impart movement to said links.

3. In a guard device for a machine having a frame and a reciprocating tool, a support bar extending laterally across the front of said frame and mounted thereon, a movable guard bar extending laterally in front of said supporting bar, a pair of crossed links having fixed pivotal connection with the supporting bar and movable pivotal connection with each other and with the guard bar, and means actuated upon the reciprocations of said tool for imparting movement to said links to project and retract said guard bar.

4. In a guard device for a machine having a frame and a reciprocating element, a cam connected with said reciprocating element for movement thereby, a supporting bar extending laterally at the front of said frame and mounted thereon, a movable guard bar extending laterally in front of said reciprocating element, a pair of crossed links having pivotal connection with the supporting bar and pivotal and sliding connection with the guard bar, and an actuating member shiftable transversely of the supporting bar and adapted to impart movement to the links when engaged by said cam.

5. In a guard device for a machine having a frame and a reciprocating part, a cam connected with said reciprocating part for movement thereby, a supporting element mounted on the frame, a movable guard element in front of said reciprocating part, a pair of crossed links having pivotal connection with one element and pivotal and sliding connection with the other element, and a plunger slidably mounted on said supporting element to be engaged by said cam and connected with said links adjacent their point of crossing.

6. In a guard device for a machine having a frame and a reciprocating element, a cam connected with said reciprocating element for movement thereby, a support mounted on the frame, a movable guard element in front of said reciprocating element, extensible and contractible linkage connected with the guard element for actuating the same, a plunger slidably mounted on said support to be engaged by said cam and having push-pull connection with said linkage, and means acting to retract said guard element.

7. In a guard device for a machine having a frame and a reciprocating part, a cam connected with said reciprocating part for movement thereby, a supporting element mounted on the frame, a movable guard element in front of said reciprocating part, a pair of crossed links having pivotal connection with one element and pivotal and sliding connection with the other element, a slotted hollow plunger shiftable on said support and arranged to be engaged by said' cam, means pro-' viding a push-pull connection between the plunger and the links adjacent the crossing point of the latter, a retracting spring in the plunger, and means extending into the plunger through the slot thereof and providing a seat for said spring.

8. A guard device for a paper cutting machine of the type having a frame and a knife carrier movable vertically and laterally thereon, comprising a supporting bar extending across the front of the machine and connected with the frame,.a guard bar extending across the machine to the front of and below said supporting bar, an inclined cam connected with the knife carrier and movable therewith, a pair of forwardly and downwardly extending crossed links having their upper ends pivoted to the supporting bar and their lower ends pivotally and slidably connected with the guard bar, and actuating means for the links including a shiftable plunger on the supporting bar and arranged to be engaged by said cam.

9. A guard device for a machine having a frame and a reciprocating element, comprising a support bar connected with the frame and extending transversely thereof, a thrust member connected with said element for movement thereby, linkage connected with said support bar arranged for projecting and retracting movement relative thereto, means on said support adapted to'be engaged by said thrust member and having operative connection with the linkage for projecting and retracting the same, and a guard element connected with the linkage and actuated thereby, said support, linkage and guard element being arranged in substantially the same plane.

10. In a guard device for a machine having a frame and a reciprocating element, a thrust member connected with said reciprocating element for movement thereby, a support mounted on the frame, a movable guard element in front of said reciprocating element, and a single pair of crossed links connecting the guard element with said support and adapted to be actuated by said thrust member for imparting movement to said guard element, said links providing lever arms having a ratio such that said guard element will be extended rapidly upon small movement of said reciprocating element.

11. In a guard device for a machine having a frame and a reciprocating part, a cam connected with said reciprocating part for movement thereby, a supporting element mounted on the frame, a movable guard element in front of said reciprocating part, a pair of crossed links having pivotal connection with one element and pivotal and sliding connection with the other element, and means having connection withthe links adjacent their point of crossing and adapted to be engaged by said cam, the pivotal connections between said links and elements being spaced to provide a lever arm ratio afiording a relatively rapid movement for the guard element.

12. In combination with a machine having a reciprocating element, a device having a guard element and a single pair of crossed links for moving the same to a forward position, said crossed links having a pivotal interconnection so positioned relative to the ends of the links that when the device is fully extended the guard element is spaced from the reciprocating element a distance greater than the length of a normal man's forearm.

13. In a guard device for a machine having a frame including a table portion and a reciprocating element, a thrust member connected with said reciprocating element for movement thereby, a support bar mounted on the frame and extending transversely thereof, a movable guard element in front of said reciprocating element, and crossed links connecting the guard element with said support bar and adapted to be actuated by said thrust-member for imparting movement to said guard element, said links and guard element operating in a plane extending from said support bar forwardly and downwardly with re- I spect to said table portion.

WALTER C. EICKMAN.

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