US1890956A

US1890956A - Bench punch

Info

Publication number: US1890956A
Application number: US548973A
Authority: US
Inventors: Harold C Spengler
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-07-06
Filing date: 1931-07-06
Publication date: 1932-12-13
Anticipated expiration: 1949-12-13

Description

' Dec. 13, 1932. c, SP'ENGLER 1,890,956

BENCH PUNCH Filed July 6, 1931 Patented Dec. 13, 1932 PATENT OFFICE HAROLD C. SPENGLER, OF ROCKFORD, ILLINOIS BENCH PUNCH Application fi eu rui e, 1931. Serial No.548,973.

This invention relates to a new and improved bench punch for metal working.

Bench punches are now mostly of the screw type and besides being complicated and expensive in construction are subject to the objections that they are slow in operation and cannot be used successfully in the punching of oval or any other non-circular forms of holes because of the tendency for the punch to turn. It is therefore the principal object of my invention to provide a bench punch of the hand-lever type sodesigned as to secure the desired power without too massive construction, and to provide a punch that is quicker in operation and adapted for the punching of practically any shape of hole.

ther objects are:

1. To provide a bench punch incorporating a punch holder guided for movement in an over-arm and linked to the punch actuating lever in such a way that the lever bears solid- 1y upon the punch holder in the punching stroke, no load being imposed upon the pivot pins of the link connection other than that of simply retracting the punch holder on the upstroke of the aforesaid lever, whereby to permit the application of considerable pressure on the punch without danger of any destructive shearing action, and make for minimum wear;

2. To provide a bench punch having provision for the mounting of different sized bolster blocks on the anvil thereof according to the thickness of stock to be worked upon, the said blocks serving as die holders.

The invention is illustrated in the accompanying drawing in which- Figure 1 is a side view of a bench punch made in accordance with my invention, the same being shown closed; and

Fig. 2 is a cross-section on the broken line 22 of Figure 1.

The punch has the body thereof suitably cast in one piece so as to provide a base 5 wlth pad portions 6 and 7 for fastening the same onto a bench or other suitable support, the said base having an anvil 8 formed at the front end thereof and an over-arm 9 extending from the back thereof reaching over the anvil. Bolster blocks 10 of different sizes are arranged to be fastened onto the anvil 8 as by means of bolts 11 entered through holes in the, flanges 12 provided on'opposite sides of the anvil. The anvil 8 is made hollow as ino dicated at 13 and provided with a counterbore 14 in the top thereof to receive a pilot portion 15 on the block 10 so as accurately to locate the block on the anvil and thus insure proper alignment between the die 16 and the I punch 17. The die 16 fits in a counterbore 18 i in the upper end of the bore 19 provided in the block 10. Each block of a set going with the punch usually has the same shaped counterbore so that a'set of dies going with the punch can be used with any block. The provision of a set of'these bolster blocks makes it possible to set up the punch for a large variety of jobs. An adjustablestop 20 is ordinarily provided in conjunction with the bolster blocks and when once set facilitates the location of the stock so that a series of pieces can be punched alike with close accuracy and with an appreciable saving in time.

The punch 17 is suitably secured in a socket- 21 provided in a plunger or punch holder 22 or may be integral therewith. The plunger or punch holder has a close working fit in a guide hole 23 in the over-arm 9, whereby to guide the punch for movement in exact alignment with the die therefor. The upper L end of the punch holder is slotted diametrically in a fore and aft plane as indicated at 24: and has a link 25 fitting therein and pivotally connected to the punch holder by means of a short pin 26 fitting in registeringtransverse holes provided in the link and punch holder. The pin is short enough to fit in the guide hole 23 in which the punch holder operates as previously stated. A punch ac- [m tuating lever 27 is pivoted at its rear end on top of the over-arm 9 at the back thereof as indicated at 28 and extends forwardly to a point over the punchholder 22 for an operating connection therewith. The lever 27 has a slot 29 provided on the under side thereof at the front-end registering with the slot 24 in the punch holder 22 and receives thelink 25 therein. A pin 30 having a drive fit'in a transverse hole 31 provided in the leve'r'27 passes freely through a larger hole 32" provided in the link 25 so as to complete the link connection between the lever 27 and the punch holder 22 to take care of the raising of the punch holder by means of the lever through said link connection, and still provide for the direct movement of the punch holder by the lever in the downstroke. In other words, the lever 27 can bear solidly on the upper end of the punch holder 22 as clearly indicated at 33 on the down-stroke of the punch, the link connection playing no part whatsoever in this operation but being adapted merely to serve in the return or upstroke of the punch to raise the punch holder by means of the lever.

' This eliminates any danger of a destructive shearing action and makes for long life, the wear being reduced to an absolute minnnum. Stripping jaws 34 are suitably secured as at 35 on opposite sides of the over-arm 9 reaching down to a point just above the top of the work to facilitate the withdrawal of the punch from the work in an obvious manner.

The punch, as will now appear, is designed for operation from in front so that the work is in plain sight as the operator pulls down upon the hand lever 86 to operate the punch. The hand lever proper is preferably in the form of a pipe threaded into a holder 37 provided on the end of a short lever 36,

which facilitates matters in the shipment of the punch, the handle being detachable, and also permits insertion of as long or short a handle as the operator desires. The lever 36 is pivoted on a bolt 38 between a pair of side plates 39 which in turn are pivotally attached to the over-arm 9 by means of another bolt 40. Nuts 41 threaded on the ends of the bolt 38 and nuts 42 threaded on the ends of the bolts 40 hold the side plates in assembled relation to the lever and over-arm. A gear segment 43 is formed on the end of the lever 36 on each side thereof and meshes with a set of forwardly and upwardly inclined rack teeth 44- formed on the top of the lever 27 at each side thereof whereby to force the lever 27 downwardly. A cam surface 45 is formed on the bottom of the lever 27 which, like the sets of rack teeth 44, is forwardly and upwardly inclined. This cam surface has a roller 46 arranged to roll thereon, carried on a cross pin 47 mounted at its opposite ends on the side plates 39, whereby to raise the lever 27 by cam action as the lever 36' is swung upwardly and rearwardly. The pin 47 is properly located so that the cam surface 45 clears the roller 46 in the clownstroke of the punch. It is only on the up stroke that the roller comes into play to force the lever 27 upwardly by rolling on the cam surface 45.

I claim:

In a bench punch of the hand lever type, comprising a body portion formed to provide an anvil and an over-arm, a die mounted ment in a hole in the over-arm to operate a punch in alignment with the die, a lever for actuating the plunger pivotally mounted at one end on the body portion and having its other end disposed over the plunger and arranged by direct engagement therewith to operate the same 011 the downstroke, the abutting ends of said lever and plunger being bifurcated, a link connection between the plunger and said lever in the bifurcated portions whereby to permit nearly full length engagement of the plunger in the hole in said over-arm for guide purposes, and a hand lever mounted for swinging movement relative to the body portion and operatively connected with the aforesaid lever for positively operating the punch holder on the downstroke by movement of the lever in one direction and on the upstroke by movement of the lever in the opposite direction, the link connection being constructed for a predetermined lost motion between the lever and plunger, whereby to insure positive engagement between the plunger and lever for downward movement of the plunger independently of the link connection, and where by the link connection serves to move the plunger upwardly on the return movement of the lever.

In witness of the foregoing I a'liix my signature.

HAROLD C. SPENGLER.

on the anvil, and a plunger guided for move-