US2182918A

US2182918A - Safety attachment for punch presses

Info

Publication number: US2182918A
Application number: US158794A
Authority: US
Inventors: John H Ferguson
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-08-12
Filing date: 1937-08-12
Publication date: 1939-12-12
Anticipated expiration: 1956-12-12

Description

, 1939- J. H. FERGUSON 2,182,918

SAFETY ATTACHMENT FOR PUNCH PRESSES Filed Aug. 12, 1957 2 Sheets-Sheet 1 lwdl/ 5&1 9% W firmwa- Afiomeys Dec. '12, 1939. J. FERGUSON, 2,182,918

SAFETY ATTACHMENT FUR PUNCH PRESSES Filed Aug. 12, 1937 2 Sheets-Sheet 2 F? nventor 0 1723221 f/awdlz/ E/g n Afforneys Patented Dec. 12, 1939 SAFETYYATTACIHMENT FOR PUNCH PaEssEs This invention relates to a safety attachment for a punch press, the general object of the invention being to provide manually operated means for moving a guard member across the work support of the press in advance of the downward movement of the ram, said means starting the press into operation.

Another object of the invention is to provide means for latching the parts in operative position while the ram is moving, with means for releasing the latch means as the ram operating shaft nears the completion of its movement, with spring means for returning the parts to nor-malposition. I

A still further object of the invention is to so form the parts that when the guard member is interrupted in its passage across the machine; such as being engaged by a part of the person of the operator, further movement'of the parts is checked, so that the press will not come into operation and the parts of the invention will not injure the operator.

This invention also consists in certain other features of construction and in the combination and arrangement of several parts, to be hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claims.

In describing the invention in detail, reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which i V Figure 1 is a perspective view showing the invention applied to the press, the press being shown in dotted lines. I

Figures 2, 3, 4 and 5 show diagrammatically how the rotation of the crankshaft of the press acts to release the latch member.

In these drawings the letter A indicates the press, which is shown in dotted lines in Figure 1 and said press includes the crankshaft a to which the connecting rod a is connected which is also connected to the ram (not shown). The press also includes the member b which controls theoperation of the press. As is well known in presses, of V the nature shown in Figure 1 the member I) when in the position shown in Figure 1 will act to move a dog out of engagement with theclutch connected with the shaft a so that the shaft is disconnected from the flywheel as soon as the dog engages said member b. However, when said member 2) is swung away from the shaft the dog will engage the clutch and thus the shaft 11 will be rotated. v I y In carrying out my invention I provide a bracketl which is fastened to the front of the upper portion of the press, as shown in Figure 1,

I and this bracket has an upwardly extending portion l which supports for rocking movement the '5" stud which is provided with a circular head 2. A rod 3 has its upper end connected with the head and its lower end carries the guard member B which includes the frame 4 and the mesh 5. These parts are so arranged that as the stud '1' is rocked in one direction the member B will move across the lower work supporting part of thepress. v

A rod 6 has one end connected with the head 2 and extends at an angle with respect to the rod 3 and said rod ti has a head i connected with its other end which receives the bent end of a link 8 which has its other end bent and held in an eye of a pivot bolt d carried by one end of an angle lever it, the other end of which is pivoted to a side of the press as shown at ll. An arm 92 is also pivoted to the member H and has a bent over ear 3 at its free end for engaging the upper edge of the lever Hi. This member l2 is'provided with'a row of holes M, one of 5 I which is adapted to receive the bent end of a link it which has its other end bent and engaging a hole in an intermediate part of a foot pedal i6 pivoted at one end to the base part of the press as shown at H and having its other end bent to 7 form a foot engaging part it. A link it has one end passing through an eye belt I? located in one of the holes M in the arm li and its other end is connected with the member b as shown in dotted lines in Figure 1. The lower end of the link has the nuts 62 thereon, the upper one of which is engaged by the eye bolt after the arm l2 moves downwardly to a certain distance.

A spring 21 connects an intermediate part of the lever ill with an upper part of the press and tends to hold the lever in raised position and a combined stop and check is provided for the lever and includes a depending bar 2! having its upper end attached to a part of the bracket l and a bar 22 is pivoted to the lower end of the bar 2! and has a screw bolt 23 extending through its upper end into the upper part of the bar 2i. A spring 24 is located on. the bolt and presses the bar 22 toward the bar 2! and thus acts to frictionally press upon the lever 98.

The upper end of the part i of the bracket is bent at right angles and receives the lower end of a pin '25 which has a head thereon and a spring'26 is located on the pin. A latch member 21 is mounted on the pin for a slight rock- 5 ing movement and also for rotary movement, the latch member being adapted to engage a wedge-shaped part 28 fastened to the head 2 and preferably in an adjustable manner. A spring 29 is connected with a part of the latch member 21 and with a projecting part 30 of the part I of the bracket.

A rod 3| is suitably connected to the upper end of the connecting rod a of the press and has at its outer end a trip arm 32 which is adjustably connected with the rod by a bolt 33 carried by an eye in the arm which receives the rod. A rod 34 is carried by the rear end of the latch member 21 and depends therefrom into the path of movement of the trip arm 32.

When the pedal is depressed the link I5 pulls down the levers I and I2 and the lever Ill pulls upon the link 8 which causes the rod 6 to partly rotate the stud 2 and thus the guard B travels across the press in front of the die and about two or three inches past the press table. As the guard reaches the end of its travel the projection 28 engages the latch member 21 and thus the parts are held in position with the guard B covering the die. The downward movement of the arm I2 causes the link iii to move the member b to a position where the flywheel of the press will be connected with the shaft (1 so that the press crankshaft a will start to rotate to lower the ram. The nuts 12" should be so positioned on the lower end of the link I9 that the eye bolt !2 carried by the lever I2 will not contact the upper nut to cause the link to release the member 22 until the guard is in guarding position and the projection 28 has engaged the latch 21. During the rotation of the shaft the rod 3| will move with the upper end of the connecting rod a as shown in Figures 2, 3, 4 and and as the crank nears the upper part of its rotation, which is the end of one revolution, the trip arm 32 will engage the depending rod 34 so that the latch member 21 is swung on the pivot 25 and thus said member 21 will release the projection 28 and this will permit the spring 2!] to return the parts to normal position such as the position shown in Figure 1, with the parts in position ready for the next operation of the press.

The parts 2| and 22 act to stop the parts on their return stroke so that said parts do not rebound and they also act as a guide and as a stop on the down stroke of lever I0. As soon as the foot is removed from the pedal IS the arm I2 will move upwardly under the action of the member b so as to stop the operation of the ram as soon as the dog comes into engagement with the member b which disengages the flywheel from the shaft.

The member B is of such a size that it will cover the die of the press when the parts are being held in position by the latch member 2! and the leverage is such that even with the pedal depressed if a part of the person of the operator, his finger, for instance, is struck by the member B or the rod 3, further movement of the parts will be stopped and the press will not trip and thus the parts will fail to move until the finger or other part of the person of the operator has been removed from the path of movement of the device. This will prevent the guard or any parts attached thereto from injuring the operator.

The rod 3| extends out over the rod 6 about two or three inches, and in case the press should repeat, the rod 3! will push on the rod 6 and thus force the guard over the die and this acts to push the operators hand out of the way which makes this part of the device a double safety feature. As stated this only happens if the press repeats.

As shown in Figure 1, I prefer. to connect the rod 3| to the connecting rod with one of the bolts that fastens the connecting rod to the crankshaft.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction and in the combination and arrangement of the several parts, provided that such changes fall within the scope of the appended claims.

Having described the claimed as new is:

1. A guard for a punch press comprising an arm supported for oscillating movement in front of the press, a guard member carried by the lower end of the arm, a foot pedal, linkage connecting the pedal with the arm for moving the arm and guard member to operative position when the pedal is depressed, latch means for holding the parts in operative position, means connected with a movable part of the press for moving therewith, for releasing the latch means after the press has completed its movement and means for moving the arm and guard member to operative position if the punch press repeats its movement.

2. A guard for a punch press comprising an arm supported for oscillating movement in front of the press, a guard member carried by the lower end of the arm, a foot pedal, linkage connecting the pedal with the arm for moving the arm and guard member to operative position when the pedal is depressed, latch means for holding the parts in operative position, means for releasing the latch means after the press has completed its movement, means attached to a movable part of the press and engaging a part of the linkage for. moving the arm and guard to operative position if the press should repeat its movement, means forming part of the linkage for moving the clutch operating member of the press to inoperative position by depression of the pedal and permitting the clutch operating member to return to operative position as soon as the pedal is released.

3. A guard for a punch press comprising an arm supported for oscillating movement in front of the press, a guard member carried by the lower end of the arm, a foot pedal, linkage connecting the pedal with the arm for moving the arm and guard member to operative position when the pedal is depressed, latch means for holding the parts in operative position, means for releasing the latch means after the press has completed its movement, means connected with a movable part of the press and engaging a portion of the linkage for moving the arm and guard member to operative position if the press should repeat its movement and means forming part of the linkage for moving the clutch operating member of the press in operative position by depression of the pedal and permitting the clutch operating member to return to operative position as soon as the pedal is released, the linkage being constructed and-arranged to cause an obstruction engaged by the guard to stop movement of the parts and prevent operation of the press even after the pedal is depressed.

4. A guard for a punch press comprising a pedal connected with the press, alever pivoted invention, what is to a part of the press, a member rotatably supported from the press, an arm extending from the member, a .link connecting the arm with the lever, a rod connected with the rotary member and extending downwardly, a guard member at the lower end of the downwardly extending part, spring means connected with the lever for moving the same upwardly, means for swinging the lever downwardly by depression of the pedal, a projection on the rotary member, a spring actuated latch member for engaging the projection for holding the guard member in operative position, means for releasing the latch member upon completion of one operation of the ram of the press and a combined stop and brake member for the lever.

5. A guard for a punch press comprising a pedal, a lever pivotally connected with a part of the press, an arm pivoted to a part of the press and having a projection for engaging the upper edge of the lever when the arm is swung downwardly, a link connecting the pedal with said arm, means for connecting the arm with the clutch operating member of the press, a rotary member, an arm connected therewith, a link connecting the arm with the lever, a rod depending from the rotary member, a guard member carried by the lower end of the rod, latch means for holding the rotary member in position with the guard member in operative position, means carried by a movable part of the press and engaging the second mentioned arm for moving the parts to operative position if the press should repeat and means for releasing the latch means to permit the parts to return to normal position, after the press has completed one operation.

JOHN H. FERGUSON.