Device and method for forming a gasket hole

A gasket punch and method for forming a gasket hole. The gasket punch is a single piece having a spherical head and a handle whereby the punch may be used to form gasket holes of various sizes up to the spherical head diameter with the gasket material on the machine part or platen and without the necessity of first forming an error prone pattern in the gasket material. The handle may have a diameter which is less than the spherical head diameter whereby the handle may be easily held and manipulated and the amount of material of which the punch is composed may be minimized. In order to provide a suitably small handle diameter without unnecessarily reducing strength and toughness, the gasket punch is preferably composed of forged steel. The gasket hole is formed by aligning the spherical head over the machine part hole with the gasket material therebetween and striking the anvil end of the handle with a hammer or causing the spherical head to impact the gasket material by a machine so that the gasket material is pinched between the spherical head and the machine part or platen hole edge and thereby severed due to the force of impact.

The present invention is related generally to the forming of holes in 
gaskets. More specifically, the present invention is related to a gasket 
punch and a method for forming holes in a gasket which correspond to holes 
in a machine part with which the gasket is to be used. 
Conventionally, gasket punches have been composed of drop-forged tool steel 
or the like and provided in sets of perhaps 6 to 11 sized hole punches 
each producing a hole of a specific standard size by means of a head 
having a circular cutting edge which is punched into the gasket material 
by means of a hammer or the like. The hammer is caused to strike a 
small-diameter handle which is integrally attached to the head and which 
is held in one's hand for such use. 
A conventional set of gasket punches disadvantageously normally require 
that a hole pattern be provided in the gasket material, the gasket 
material removed from the machine part after the pattern is made, and the 
hole then punched as indicated by the pattern. This is a time-consuming 
process and, if the pattern and punching are not formed carefully, errors 
may result with a corresponding waste of time and/or material. 
Furthermore, as previously noted, the craftsperson must undesirably carry 
around a large number of gasket punches in order to adequately perform the 
work. In addition, as the number of gasket punches in a set increases, the 
cost of the set also disadvantageously increases. Furthermore, such gasket 
punches may wear out after a period of time and thus have limited life. 
It is accordingly an object of the present invention to provide a gasket 
punch which may be used to form gasket holes of various sizes so as to 
reduce the number of gasket punches required to perhaps one to three. 
It is another object of the present invention to provide a gasket punch 
which permits the hole to be formed while the gasket material is 
positioned on the machine part so that it is unnecessary to first provide 
a pattern in the gasket material. 
It is a further object of the present invention to provide such a gasket 
punch which is rugged, reliable, and of a single-piece construction yet is 
inexpensive to manufacture. 
In accordance with the present invention there is provided a gasket punch 
which comprises an elongate handle means and means defining a spherical 
head integrally connected to one end of the handle means for punching a 
gasket hole, and the handle means has a diameter which is smaller than the 
spherical head diameter. Such a gasket punch may cooperate with a machine 
part or platen hole to produce a hole in gasket material which is of the 
same size as the machine part or platen hole up to the diameter of the 
spherical head whereby perhaps one to three such hole punches may replace 
an entire set of perhaps six to eleven conventional hole punches. The hole 
is punched while the gasket is positioned on the machine part or a platen 
carrying the desired hole pattern whereby it may be unnecessary to first 
provide a pattern in the gasket material for the hole. The spherical head 
is caused to impact the gasket material overlying a hole in the platen 
either by use of a hammer or the like or a machine to pinch the gasket 
material between the edge of the hole and the spherical head and thereby 
sever the gasket material due to the force of impact to provide a similar 
hole therein. The smaller diameter handle allows the expensive material of 
which the gasket punch is composed to be minimized while also allowing 
easier handling. 
Various other objects, features, and advantages of the present invention 
will be more fully appreciated when considered in connection with the 
accompanying drawings in which like reference numerals designate the same 
or similar parts throughout the several views.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIGS. 1 and 2, there is shown at 10 and 12 a set of two gasket 
punches which are similar but of different sizes. Thus, gasket punch 12 
may be used for punching relatively smaller gasket holes while gasket 
punch 10 may be used for relatively larger gasket holes. Except for this 
difference in sizes, gasket punches 10 and 12 may be described similarly 
so that description herein of one is meant to also refer to the other one. 
Like reference numerals will also refer to like parts thereof, and, with 
this understood, the description will be primarily with reference to 
gasket punch 10. 
Gasket punch 10 is composed of a suitable material such as forged steel for 
suitably punching gasket holes as described hereinafter. It includes a 
shaft 14 that serves as a handle and transmits an impact force produced by 
a hammer, illustrated at 16 in FIG. 3, or other suitable means from the 
anvil end 18 to the working end 20. 
A spherical head 22 is connected to the working end 20 of the shaft 14 and 
is integral therewith so that the gasket punch 10 is of a single-piece 
construction. The head 22 is provided with a spherical shape so that it 
may cooperate with a range of machine part hole sizes to transmit the 
impact force to pinch the gasket material, illustrated at 44 of FIG. 3, 
between the head 22 and the circumferential edge of the machine part hole, 
illustrated at 46 in FIG. 4, to advantageously thereby cut a hole in the 
gasket material to the size of the machine part hole while the gasket 
material is positioned on the machine part without the necessity of 
providing a pattern in the gasket material first, and the spherical shape, 
allowing such holes to be formed up to the diameter of the head, permits 
the number of gasket punches in a set to be minimized to perhaps one to 
three gasket punches. 
The diameter of the head 22, illustrated at 24 for punch 10 and 26 for 
punch 12, must be larger than the diameter of the largest hole to be 
punched therewith. On the other hand, such a diameter for the handle 14 
may cause the punch 10 to be difficult to handle and manipulate as well as 
requiring additional expensive tool steel in its manufacture. In order to 
minimize the amount of expensive tool steel required in the gasket punch 
10 so that it may be manufactured more inexpensively as well as to provide 
a suitable handle size for easy holding and manipulation thereof, the 
diameter of the handle 14, illustrated at 28 for punch 10 and at 30 for 
punch 12, is preferably equal to less than about 5/8 inch whereby it is 
less than the spherical head diameter 24 and 26 respectively, particularly 
where the spherical head diameter is greater than 5/8 inch. 
As shown in FIG. 3, the handle 14 preferably has a length, illustrated at 
32 for punch 10 and 34 for punch 12, which is sufficient for easily 
holding and manipulating the gasket punch 10 by one's hand, illustrated at 
36, and will generally increase as the spherical head diameter increases. 
Thus, the handle length 32 and 34 is preferably at least about 4 inches 
and should typically range between about 5 and 7 inches. 
For accommodating a range of machine part hole sizes up to about 11/8 
inches diameter, a set of two gasket punches 10 and 12 may be provided 
wherein the diameter 24 of the first punch 10 may be about 11/8 inches and 
the diameter 26 of the second punch 12 may be about 3/4 inch. The handle 
14 for gasket punch 10 may have a diameter 28 which is equal to perhaps 
about 5/8 inch and a length 32 which is equal to about 6 inches. The 
handle 14 of gasket punch 12 may have a diameter 30 which is equal to 
perhaps about 1/2 inch and a length 34 which is equal to perhaps about 
51/4 inches. The junction between the handle 14 and head 22 of gasket 
punch 10 may be machined to have a radius illustrated at 38 of perhaps 
about 9/16 inch. The junction between the handle 14 and head 22 of the 
gasket punch 12 may be machined to have a radius, illustrated at 40, of 
perhaps 3/8 inch. A third larger size gasket punch may be provided if it 
is desired to have the ability to punch holes greater than 11/8 inches in 
diameter. Thus, such a third gasket punch may, for example, have a head 
diameter of perhaps about 11/2 inch to punch holes having diameters from 
about 11/8 inches to about 11/2 inch, a handle diameter of perhaps about 
5/8 inch, and a handle length of perhaps about 6 inches. For another 
example, a set of three gasket punches may be provided wherein the 
spherical heads have diameters of 1/4 inch for small holes up to 1/4 inch 
diameter, 3/4 inch for holes 1/4 inch to 3/4 inch diameter, and 11/2 
inches for holes 3/4 inch to 11/2 inch diameter. It should be understood 
that the above dimensions are for illustrative purposes only and not for 
purposes of limiting the scope of the present invention and that other 
embodiments having other dimensions may be provided which come within the 
scope of the present invention. 
If desired, the handle 14 may be provided with a suitable knurl. For 
example, gasket punch 12 may be provided with a medium knurl over a length 
of 11/8 inches spaced 1 inch from the anvil end 18. 
While the handle 14 has been shown as being cylindrical in shape, it should 
be understood that it may have any other suitable cross-sectional shape 
such as hexagonal. When describing such other shapes, the handle diameter 
28 and 30 is defined herein as the largest dimension of the handle 14 as 
seen in a cross-sectional view taken in a plane perpendicular to the 
longitudinal direction thereof. 
The gasket punches 10 and 12 should be hard and strong to maintain 
dimensional integrity yet must also resist spalling and other types of 
damage which can occur as a result of impact loadings. In order to provide 
such qualities, the gasket punches 10 and 12 are preferably produced from 
a medium/high-carbon alloy tool steel. Suitable shock-resisting tool 
steels may be characterized by, for example, a 0.5 percent carbon content 
and 1 to 2 percent silicon. Chromium, molybdenum, manganese, and tungsten 
may also be suitably alloyed in varying proportions in such steel for 
resistance to creep, wear, heat, and shock in accordance with principles 
commonly known to those of ordinary skill in the art to which this 
invention pertains. Examples of suitable tool steels are those within the 
range of about 4140 to 4150 tool steel. Although the punches 10 and 12 may 
be manufactured by casting in a dual-cavity die tooling or by welding 
steel ball bearings onto suitably shaped and formed handles or by any 
other suitable process, they are preferably manufactured by forging from 
tool steel. In order to withstand considerable impact loadings, the 
punches 10 and 12 may suitably be drop forged and heat-treated, including 
case hardening and tempering, in accordance with principles commonly known 
to those of ordinary skill in that art to which this invention pertains, 
and finished by machining burrs therefrom. The punches 10 and 12 are 
forged to concentrate the grain structures and fiber formation at the 
points of greatest shock and stress so that the grain structure is free of 
most internal defects with a more uniform structure that will help 
response to stress to be more predictable and to generally make the piece 
stronger and tougher. As opposed to cast or machined parts which are 
likely to be either straight or even without a particular grain flow, the 
grain flow of a forged part desirably follows the contour of the part. 
Forging permits the reduction of dead weight in parts simply for stress 
resistance and thus permits the diameter 28 and 30 of the handle 14 to be 
reduced without unnecessarily reducing strength and toughness. 
Referring to FIGS. 3 to 5, there is illustrated a method of use of gasket 
punch 10 for forming a hole, illustrated at 42, in a piece of material 44 
which corresponds to hole 46 in machine part 48 while the material 44 is 
positioned thereon so that it is unnecessary to first provide a pattern in 
the material 44. The material 44 may be any suitable relatively thin 
material in which it is desired to punch a hole conforming to a hole in a 
machine part or the like. For example, material 44 may be gasket material, 
which may have a thickness of perhaps 1/16 inch, shim stock, cardboard, 
leather material, sheet metal, or the like having a suitable thickness for 
punching a hole therein. Material 44 will be referred to hereinafter as 
"gasket material." The handle 14 is held in one's hand 36 and the punch 10 
positioned so that the spherical head engages the gasket material 44 and 
is aligned over the machine part hole 46, as seen in FIG. 4, with the 
gasket material 44 being between the spherical head 22 and the machine 
part hole 46. The gasket punch 10 is then struck with a hammer 16 or the 
like as indicated at 50 on the anvil end 18 to transmit an impact force 
through the spherical head 22 to cause the gasket material 44 to be 
pinched between the rim or edge of the machine part hole 46 and the 
spherical head 22 and the head 22 forced through the gasket material 44 so 
that it is severed along the machine part hole edge. Each additional 
gasket hole corresponding to additional machine part holes is similarly 
punched while the gasket material 44 is held in position on the machine 
part 48. The gasket punch 10 can be used for machine part holes 46 having 
diameters up to the diameter 24 of its spherical head so that gasket punch 
10 may replace several gasket punches having conventional circular cutting 
edges. Since the hole 42 and other required holes are punched while the 
gasket material 44 is on the machine part 48, it is no longer necessary to 
first provide a pattern, which may be error prone, in the gasket material 
44. 
Referring to FIG. 5, after the gasket hole 42 is punched, the severed blank 
of gasket material, illustrated at 52, may be conveniently removed 
therefrom by insertion of the relatively small diameter anvil end 18 of 
the gasket punch 10 and prying the blank 52 therefrom. 
Referring to FIG. 6, there is illustrated an alternative method of use of 
gasket punch 10 for punching a hole or holes in gasket material 44 wherein 
gaskets with pre-punched holes may be manufactured for sales to customers. 
The gasket material 44 is suitably positioned on a platen 60 which 
contains a hole 62 or holes corresponding to the sizes and locations of 
holes to be punched therein. The gasket punch 10 is aligned with the hole 
62 and held in a chuck 64 of a suitable machine 66 which is built and 
preferably suitably programmed, in accordance with principles commonly 
known to those of ordinary skill in the art to which this invention 
pertains for automatic operation. Suitable means, illustrated at 68, are 
provided for providing reciprocating movement of the chuck 64 and the 
punch 10 carried thereby so that the gasket punch head 22 is moved, as 
illustrated at 70, toward the hole 62 and impacts the gasket material 44 
to pinch the gasket material between the platen hole rim or edge and the 
spherical head and sever the gasket material due to the force of impact 
and thereby punch a hole of the same diameter in the gasket material, as 
previously discussed. A suitable machine with which gasket punch 10 may be 
used is, for example, a machine identified as a Strippit FC 1500/45 turret 
punch press marketed by the Strippit/Di-Acro Division of Houdaille 
Industries Inc. of Akron, N.Y. The handle 14 is of course suitably sized 
for the chuck 64. 
Additional uses for punches 10 and 12 may include countersinking holes for 
screws, knocking out dents in fenders and sheet metal, as a knock-out 
punch for removing rusted bolts, and as a dry wall nail setter. 
Thus, there is provided a single piece gasket punch for producing holes in 
gasket materials more easily and quickly. While the spherical head must be 
greater than the diameter of the largest hole to be punched therewith, the 
handle diameter is minimized for easier handling as well as for reducing 
the amount of expensive tool steel required for its manufacture. Forging 
of the punch permits such a minimized handle diameter without 
unnecessarily reducing strength and toughness. A single gasket punch of 
the present invention may be long wearing and replace several gasket 
punches having conventional relatively fast wearing circular cutting heads 
for added convenience to the craftsperson. 
It is to be understood that the invention is by no means limited to the 
specific embodiments which have been illustrated and described herein and 
that modifications may indeed be made which come within the scope of the 
present invention as defined by the appended claims.