US2404675A - Safety guard - Google Patents

Description

M 23, 19%;. A E WS ZAMfiWS SAFETY GUARD Filed Dec. 11, 1943 FIG. u

HNVENTOR ALAN E. VQSBURG I BY FIG. 3

VATTQRNEY Patented July 23, 1946 SAFETY G ARD Alan E. Vosburg, Chicago, Ill., assignor to Teletype Corporation, Chicago, 111., a corporation of Delaware Application December 11, 1943, Serial No. 513,981

3 Claims. (01. 74- 15) This invention relates to safety appliances and more. particularly to a safet guard to protect an operator duringv the use of hazardous machinery, such as punch presses and the like.

During machine operationson various types of relatively small piece parts, it is frequently necessary that the piece parts he successively fed to various points thereon whereat the operation is to be performed. While there have been many devices proposed to impart automatic stepping motion to the piece parts, in many cases it is necessary that the step-by-step feeding be done manually.

,At the present time there has been perfected many different types of safety appliances to be utilized with machinery such as punch presses and the like, for the protection of the operator. Probably the best known types are of the cage variety which extend completely around the reciprocating tool holder and tool of the machine and are either raised upwardly or have a pivoted opening by means of which the piece parts may be moved after the machine operation, and the swinging arm type which is simply a pivoted arm which automatically reciprocates from side to side between the operator and the operating machine parts during-operation thereof. While it is true thatthese devices work satisfactorily, it is necessary that they be built well away from the reciprocating tool of the machine which, therefore, precludes theoperatorfrom keeping his hands adjacent the tool during operation. This is a distinct disadvantage in that machinery that is used to operate on small parts is often provided with manual piece part feed means, which necessitates the machine operator having his hands close to the moving tool. Thus, such a safety device could not be used on machinery having the above-mentioned feed means.

Accordingly, the object of this invention is to provide a safety apparatus which while serving to protect the machine operator allows the perators hands to be in close proximity to the reciprocating tool holder and tool of the machine.-

The invention consists of an elastic cage which, under all conditions of a reciprocating tool holder, provides a barrier against inadvertent exposure of an operators hands to injury by the tool and die elements. Such precautions are aggrevated in the case of code segment punching where an arcuate piece part is variously positioned as a code notch cutting punch is operated to remove various peripheral sections according to the particulars of a coded element;

'the lower frame.

The present safety apparatus comprises, in general, an upper plate which is securely fastened to the reciprocating part of the machine onwhich it is used, which part may secure a punch or the like, a lower frame which is removably secured to the lower die shoe, and a plurality of springs extendingbetween the upper plate and Thus, the plate, frame, and springs form a compact unit which is a constant protection to the operator but which may be be stationary, resulting in a constant extending and compressing of. the springs therebe-tween.

The features and advantages of the invention will become apparent from the following detailed description of a specific embodiment thereof, when read in conjunction with the following drawing in which:

Fig. 1 is a detailed perspective view, partly broken away, of the device embodying the invention as attached to a power punch press;

Fig. 2 is a detailed view of the upper plate forming part of the invention, as viewed by looking upwardly, as in Fig. 1; and

Fig. 3 is an enlarged perspective view, partly broken away, showing the connection between the device embodying the invention and the base to which it is connected.

The present invention has been illustrated and will be described as being used in connection with a power punch press. However, such an ap- Dlication has been used for the sake of illustration only and it is to be understood that the invention is applicable to many other types of industrial machinery.

As shown in Fig. 1, the punch press comprises a basal! on which is securely positioned a die shoe H, by means of any suitable fastening devices (not shown). The die shoe l2 has an up wardly extending circular section [3 which. is smaller in size than the outer contour of the baseof the die shoe. Rotatably positioned around the upwardly extending portion l3 of the die shoe I2 is a feed ring [4 which may be manually positioned by means of three upwardly extending rods 16. A segment ll of the feed ring I4 is formed on its front edge with a series of notches 18 which serve as guides for successive feeding movements of the ring [4. A post [9 is mounted on the die shoe 12, carrying a pawl 2|! towards its top and having aspring 22 thereon normally urging the pawl in a clockwise direction, as viewed 3 in Fig. 1. The pawl 2| is positioned in line with and adjacent the segment I! of the feed ring 14 and is utilized to engage the notches ill in the segment l'l, thus holding the feed ring I4 in the position to which it has been set. A pin 23 is mounted on the die shoe l2 and acts as a limit to the outward movement of the pawl 21 when the operator manually rotates it in a counterclockwise direction, as viewed in Fig. 1, against the tension of the spring 22, in order to release its-1e end from a notch I8 and thus be able to position.

the feed ring I4 to the next notch. This is done successively throughout the -number ofnctches IS in the segment I1.

A piece part 24 is located in place on the feed ring 14 by means of two pins 25 which pass through two holes in the piece--part 24. Astheiece part 241s arcuate in shape two guides. 21,

are provided, one near either end of the piece part, in order to more securely hold the piece part in place for the punching operation. The guides 21* are secured to the feed ring l4 by any suitablemeans (not shown) The specific'piece part 24 which hasbeen illustrated in the: drawing is a blank which is to be formed witha series of notches of various sizes and at various points in the edge having the smaller radii. After manufacture, this particular. piece part isused as a code bar in printing telegraph apparatus.

Four locating pins- 29 are securely fastened 1 within. the circular upwardly extending portion l 3.of the die. shoe [2. Asmore clearlyshown in Fig. 3,. the locating pins 29 are formed with a shoulder 3|, a head 32, and a-metal stock 33separating the head and the shoulder but being less in. diameter than the head orshoulder. The utility. ofithe locating pins will be explained hereinafter.

ASaELlSO; shown in. Fig. 1, a punch holder 36 is illustrated as being above the members just described, and separated therefrom. The punch holder 3ii hasva. block 31 positioned at the front, which is secured tothe punch: holder by means of bolts 38. and tightened thereon by means of nuts 3-9. Upon loosening the nuts- 39 it is possible to insert an upwardly extending cylindrical-portion. (not shown) of the punch block 4!. The punch. block 4|. has a. punch- 42 extending downwardly therefrom-whichperforms the notching operations on the piece parts 24. As thepunch block 41 is removable it is possible to change the type of punch utilizedv inthe machine, depending upon the type of notching operation to be performed.

A frame 45 having anvupwardly extending edge 41 on all four sides thereof is removably secured to the circular upwardly extending portion I3 of. the die shoe. 12 by means of the locating pins 29. Asmore clearly shownin Fig. 3, the-frame 46 has a seriesof four specially formed openings each of which comprises a large circular opening 48 which is slightly larger in size than the head 32. of the locating. pin 2 9, and a-slotted portion 49,

which is. slightly wider than the metal stock 33,

extending from the circular opening 48 lengthwise of the frame 46.. The circular opening 48 and the slot 49 together assume the shape of a keyhole. Thus, it is possible to removably secure the frame 45 to the die shoe l2 by slipping the frame over the locating pins 29, the circular opening 48 passing over the head-32. The frame is thenpulled forwardly, as viewed in Fig. 3, which results in the metal stock 33 of the locating pin29, which-is between the head.32 and the slot 49 is just slightly wider than the stock 33 the frame 46 cannot pass up over the head 32 nor down over the shoulder 3|. The frame is thus mounted to the die shoe l2 and will resist any vertical. motion". In order to remove the frame 45 it is only necessary to impart horizontal motion to the frame to the extent that the circular opening 48 will be positioned in alignment with the head 32 of the locating pin 29, the frame then being lifted over the head of the locating pin 29.

A plate 51, as shown in Fig. 2, is formed with a circularopening; 52, three small screw openings in which are; shown screws 53, and a flange 54 extending from all four sides of the plate 5|. The plate is designed'to be positioned above the punch block 4|, the cylindrical member by which the punch block is held in the upper block 36 and which is not shown in the present drawing passing through the circularopening 52. Theplate 5| is then securely fastened tothe punch block 4| by means of the screws 53 which pass through the screw holes in the plate. The plate is shown after it has been secured in position in Fig. 1, wherein the flange 54 is shown as extending downwardly,

Both the lower flange 41' and the upper flange 54 have a series of aligned openings therein formed at spaced intervals the entire length of the flanges. A series of springs BB having hooked ends engage the openings and extend between the upper plate 5! and lower frame 41. The springs 56 should be so made that when the upper block 35 is in its upward position, at which-time no punching occurs, the springs are extended.

During the operation of the punch press, the upper member 36; and the-parts secured thereto, move downwardly to a pointat which the punch 42 notches the piece part 24. During this operation the'springs 56 will no longer be held under tension but instead will be put under a certain' amount of compression which may cause the springs to buckle inwardly, outwardly, or toward the sides; However, because ofthe great number of springs used and the relatively small amount of movement of' the upper member 35, the resulting relatively small amount ofcompression of the springs does not permit sufficient movement of the springs to present any large opening between any two adjacent springs. Thus, it maybe seen that thesafety appliance embodying the present invention may be constructed as a compact unit and be placed in close proximity to the working parts of the machine on which it is installed. For this reason, it is possible for a machine operator to-place his hands in close proximity to the operating parts to feed a piece part, or for any other reason, and yet be protected from injury from thereciprocating punch by means of the safety device abovedescribed.

Althougha specific embodiment of the invention has been shown and described, it will be-understood that this embodiment is but illustrative and that various modifications may bemade therein without departing from the sco-peand spirit of this invention.

What is claimed is:

1. In combination with a punch-press including a reciprocating punch holderand a stationary die shoe, asafety device comprisinga plate securely connected to said reciprocating punch holder, a frame having openings therein formed of a large circular section and a slot joining the circular section removably connected to said stationary die shoe through bolts in said die shoe engaging the openings in said frame, and a plurality of springs each connected to said plate and to said frame, whereby upon reciprocation of said punch holder said springs will be compressed and extended to afford protection to the punch press operator under all conditions of operation.

2. In combination with a punch press including a reciprocating punch holder and a stationary die shoe, a safety device comprising a plate securely connected to said reciprocating punch holder, a frame having openings therein formed of a large circular section and a slot joining the circular section, means to reinovably connect said frame to said die shoe including bolts in said die shoe engaging the openings in said frame, and a plurality of springs each connected to said plate and to said frame, whereby upon reciprocation of said punch holder said springs will be compressed or extended to afford protection to the punch press operator under all conditions of operation.

3. In combination with a punch press including a reciprocating punch holder and a stationary die shoe, a safety device comprising a plate securely connected to said reciprocating punch holder, a frame having a plurality of openings therein each formed of a circular opening and ahorizontally disposed slot connecting thereto, a plurality of pins securely fastened to said die shoe each formed with a circular head slightly smaller in size than the circular opening in said frame a reduced body section directly below said head slightly smaller in size than the slot in said frame, and a wide shoulder immediately below the reduced body section, said pins and openings cooperating to allow said frame to be removably secured to said die shoe, and a plurality of springs each connected to said plate and to said frame, whereby upon reciprocation of said punch holder said springs will be compressed or expanded to afi'ord protection to the punch press operator under all conditions of operation.

ALAN E. VOSBUR'G.

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