US 1922614 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Aug. 15, 1933. c. 'r. BRADsHAw PUNCH Filed Oct. 8, 1931 gill- 12.294441 Charles T racSuxJ/U,
norneg Patented Aug. 15, 1933 UNITED STATES PATENT OFFICE PUNCH i j charles T. Bradshaw, Philadelphia, Pa. Application October 8, 1931. Serial No. 567,742
This invention relates to improvements in manually operated punches for punching' holes in sheet material of various kinds.
The object of the invention is to provide a punch of novel, inexpensive and efficient construction having means whereby the punchings may be easily and automatically ejected from within the cutting die, and having means whereby the punch may be quickly and accurately centered upon the work or material to be acted upon thereby. i
The invention resides in the elements of the punch and the combinations of them herein-4 after described and claimed.
In the accompanying drawing, illustrating the invention,
Figure 1 is a side view of a punch showing one form of embodiment of the invention.
Figure 2 is a side view thereof as seen at right angles to Fig. 1.
, Figure 3 is'a longitudinal section of the punch,
on line 3-3 of Fig. 2.
Figure 41s a transverse section, on line 4 4.
of Fig. 1. 1
- `Figure 5 is a side view of another form of embodiment of the invention.
Figure 6 is a side view of the punch shown in Fig. 5, as seen at right angles thereto.
Figure 7 is a longitudinal section of the punch, 30, on une '1 -7 of Fig. 5.
Figure `Sis a transverse section, on line 8-8 of Fig. 5, omitting the spring. r l
Referring to Figs. 1 to 4, inclusive, 2 designates' the body member 4of the punch which in this what tapered at one end portion, as illustrated. l
The tapered end portion of the member or bar y 2 has an axial bore 4 therein which extends a considerable distance into the member, rand the tapered end of the member is provided with an annular cutting edge 5which surrounds the open end of the bore 4 and constitutes the cutting die of the punch. The opposite end of the member or bar 2 is adapted to receive hammer blows to drive the cutting die of the punch through the material to be cut or punched in the usual manner when the punch is inservice. Y
A cylindrical plunger 6 is slidably tted within the outerend portion of the bore 4 so as to be longitudinally movable therein, and, in the normal position of the plunger, as shown in the drawing, the lower or outer end surface thereof is at the plane of the cutting edge 5 of the Y .punch or substantially so.
Side Walls of the body member 2 on opposite instance is in the form of a cylindrical bar somesides of the bore 4 therein are provided with oppositely-arranged, longitudinally-extending, parallel slots 9 which open into the bore and extend through the walls of the member to the exterior thereof.
The inner end portion of the plunger 6 carries a pin 10 which extends transversely through the same and has its end portions extending outwardly from the respective sides of the plunger and into the slots 9. The pin 10 and the walls 65 of the slots 9 serve to limit the extent of the longitudinal movement of the plunger 6 within the bore 4,'and the end walls of the slots 9 nearest the cutting edge 5 prevent downward or outward movement of the plunger l6 beyond its normal po- 70 sition.
A helical spring 11 is housed Vwithin the bore 4 and exerts pressure against the inner end wall of the bore and the inner end of the plunger 6 and holds the plunger yieldingly in its normal position' from which it may be moved inwardly against the action of the spring 11` and to which it will be automatically returned by the spring when inward pressure against the plunger is re-4 moved.
The inner end of the plunger 6 is provided with a centrally arranged projection 12 which extends into the adjacent end of the spring 11 and holds it in a' central position with relation to the plunger for the proper operation of the spring and plunger and for the prevention of undue friction between the helices of the spring and the annular wall of the bore 4.
The lower or outer end of the plunger 6 is provided with a pointed centering pin 13 which pro- 90 jects downwardly or outwardly from the center ofthe outer end surface of the plunger in axial alinement with the plunger and the cutting die, as clearly shown in the drawing.
It will now be understood that when the punch is in service the cutting die may be easily and quickly centered over the hole to be cut in the material to be acted upon by placing the point of the centering pin 13 upon or near a suitable dot or mark upon the material. Itwill be understood also that when a holeis punched in the material, the pin 13 and plunger' 6 will be moved inwardlyA against the pressure of the spring 11 which, when the punch is removed from the material, will move the plunger outwardly to its normal position and thus automatically eject the punchingr from the cutting die.
If the spring 11 should fail to return the plunger to normal position after one or more punching operations, and one or more punchings should become clogged within the cutting die, due to the character of the material being acted upon, the plunger 6 may be readily forced back to normal position to eject the clogged punchings by the aid of a hammer or other tool or instrument applied to one or both of the outer endportions of the pin which are extended outwardly beyond the slots 9 for this purpose.
Another purpose of projecting the end portions of the pin 10 outwardly from within the slots9 is that'they prevent the cylindrical body of the punch from rolling away when it is laid upon a work bench or table which is not perfectly level,
. connecting the head and handle 16 and extending laterally. from the handle and longitudinally from the head, as illustrated in the drawing.
lThe head 15 is made tapered and has an axial bore 18 extending therethrough and it is pro- .vided with an annular cutting edge 19 which surrounds the lower or outer end of the bore 18 and forms the cutting die or", the punch.. rJhe outer or upper end of the handle 16 is adapted to 'receive hammer blows to drive the cutting die through the material tol be punched. Y
A cylndrical plunger 20 is slidably fitted within the bore 18 of the head 15 and it is longitudinally movable therein. In the normal position of the plunger 20, as shown in the drawing, the
lower or outer end surface. thereof is at the plane ofthe cutting edge 19 or substantially so.
"The upper or inner end portion of the plunger 20 extends into the space between lthe head l5 and the handle 16 and it is provided with a pin 2lY which extends transversely therethrough and has its end portions extending. outwardly from the respective sides thereof and is adapted to engage the inner or upper end oi the head 15 and prevent outward or` downward movement of' the plunger beyond its normal position.
TheA inner or lower end portion of the handle 16 is provided with a bore 22 in axial alinement.
with andof less diameter than the bore 18 in the Vhead 15, and the inner or upper end portion of the'plungerr 20 is Yprovided withv core `23 having a diameter substantially ythe same as the diameter of the handle bore 2,2 and in alinement therewith. v
helical spring 24 extends between the nandie 16 and the plunger 20 and has its respective end portions housed within the bores 22 and 23. The spring 24 exerts pressure against the handle 16` and against the plungerv 2() and holds the plunger:l yieldingliy in` its normal position and from which .it may be moved or pressed inwardly against the', 'action ,of the spring.
The lower or outer end of theplunger. 20 is provided with a pointed centering pin 25which projects downwardly or outwardly from the center of the outer surface of the plunger..
The functions and operations of the plunger 20, spring 24 and centering pin 25, are the same as the unctions and operations ol the plunger 6, spring 11 and centering pin 13, previously described.
I claim my invention:
l. A punch comprising a body member having a head forming one end portion thereof and a handle spaced from the head in axial alinement therewith and forming the opposite endportion of the member and connected to the head by spaced arms which extend longitudinally from the head and laterally from the handle, said head having an axial bore extending therethrough and a cutting edge surrounding the outer end thereof, a plunger slidable in the bore and extending into the space betweenthe head and the-handle and having an outer end surface in the region of the plane of the cutting edge in the normal position of the plunger, a pin penetrating the pl erger andprojectingoutwardly therefrom within'said space and adapted to engage the inner end of said head and prevent outward movement of the plunger beyond its normal position, said handle having a bore therein'opening into saidspace and in axial alinement with. and of less diameter than the bore in the head, said plungerhaving a bore in the inner end portion thereof4 of substantially the diameter of the bore in the handle and alined therewith, a helical spring having its endportions extending into the bores in the handle and theplunger and acting against plunger to yieidingly'hold it in its no nai position, anda pointed centering pin projecting from the center of-said end surface.
A punch comprising a body member having a head forming one end portion thereof and a handle spaced. from the head in axial alinesaid head h ving an axial bore extending therethrough and a cutting edge surrounding the outerend thereof, va piunger slidable Yin the bore and extending into thespace between the head and the handlerand having an outer surface'in the region of ,the plane of the cutting edge in the normal position of the plunger and carrying a part projecting laterally thereirom'within said space and adapted` to engage the inner end ci head and prevent outward movement of the plunger beyond its normal position, said handle having a bore therein opening into said space and in axial alinernent with and of less diameter than the bore in said plunger having a bore in the inner end portion thereof of substantially the diameter of the bore in the handle and alined therewith. a helical spring having its end'portions extending into the bores in the handleand plunger and acting against the plungerto yieldingly hold itin its normal. position, and a pointed centeringV pin projecting from the center of said surface.
CHARLES T. BRADSHAW.