Note: Descriptions are shown in the official language in which they were submitted.
--1--
This invention relates to removable, one-piece,
stamped sheet metal, push-on stud retainers and in
particular relates to relatively thin walled, one-piece,
stamped sheet metal, removable push-on stud retainers
5 having minimal transverse dimensions and utilizing the
relatively smooth continuous edge of a punched or pierced
hole as the stud retaining edge of the stud retaining
aperture and having a tab which may be gripped and then
pulled to ~lit the fastener for selective removal of the
10 fastener from a retained stud.
Description of the Prior Art
One-piece, stamped sheet metal, thin walled stud
retaining fasteners of the push-on type are well known in
the prior art. Examples of such prior art devices may be
15 seen by reference to United ~tates Patent Nos. 1,675,277,
issued June 26, 1928; 2,975,667, issued March 21, 1961;
2,986,060, issued May 30, 1961; 3,032,807, issued May 8,
1962; and 3,108,371, issued November 29, 1963. Many of
the prior art devices were formed by punching or piercing an
20 aperture into a sheet metal blank and then slotting or
slitting the edges of the punched aperture to provide a
stud retaining aperture having a plurality of stud retain-
ing fingers. Other prior art devices were formed by
punching or piercing a hole into a sheet metal blank from
25 a first direction and then forming a generally dome shaped
impression from the other direction to achieve a fastener
having a generally frusto-conical cross-sectional shape.
The forming of the generally dome shaped impression from
Z-~
--2--
the direction opposite the direction of the punching of
the hole assured that the "burr edge" of the punched hole
was the stud retaining edge of the stud retaining aper-
ture. The above mentioned ~nited States Patent No.
5 3,108,371, at Column 4, lines 37 to 51, is an example of
such a so-called "reverse formed" stud retaining fastener.
Other prior art devices utilized a swaging operation to
assure that the stud retaining edge of the stud retaining
aperture was given a rough, biting surface. The prior art
10 stud retaining fasteners operated by frictionally gripping
the exterior side walls of a retained stud. Such prior art
devices usually resisted undesired removal of a retained
stud by bitingly penetrating the outer edge of said studs
and were not easily removed. While such prior art stud
15 retaining fasteners were generally suitable for most
applications, the present tendency to use such fasteners
in so-called miniature and/or microminiature devices has
led to an attempt to minimize the outer transverse
dimensions of said fasteners. Reduction of the transverse
20 dimension of such fasteners will allow the retention of
studs on closer centerlines. Prior attempts to minimize
the other transverse dimensions have been relatively un-
successful as the prior art push-on fasteners have utilized
a stud retaining aperture having a rough biting edge or
25 burred edge and/or a slotted or slitted edge to provide
the stud engaging edge of such fasteners. The use of such
burred edge and/or slitted edge has prevented attempts to
minimize the outer dimensions of said prior art fasteners
as the burred and/or slitted edges contained many cracks,
30 discontinuations, stress concentrations and/or irregular-
ities therein which has resulted in premature cracking
and/or other failure of the fastener body unless at least
a predetermined minimal outer dimension thereof was
provided.
11~16Z4
According to the present invention therc Ls prov-lded
fl one-lLcce, stamped shect metnl, removable stu(l retainLng
fastener including a body having a generally continuous,
generally centrally located stud retaining aperture and a
generally continuous, generally dome shaped impression
generally coaxial with the aperture. The aperture defines
a stud retaining edge, the aperture being formed from a
pierced hole having a relatively smooth continuous and a
burred edge. The stud retaining edge being formed from the
relatively smooth continuous edge of the pierced hole. A
tab extends from the body.
In accordance with the present invention, many of
the drawbacks of the prior art devices have been overcome
by the provision of the improved, removable, one-piece,
thin walled, stamped sheet metal push-on stud retaining
fastener having a minimized outer transverse dimension.
The above is accomplished by utilizing the relatively smooth
continuous edge of a hole punched or pierced in the sheet
metal blank rather than the burred edge of the hole punched
in the sheet metal blank as the stud retaining edge of the
stud retaining aperture of the fastener. Applicant has
discovered that when the dome shaped impression is formed
in the sheet metal blank after the hole is punched therein
from the same direction as the direction from which the hole
was punched, the relatively smooth edge of the punched hole
is compressingly formed into a strong, sharp, relatively
uninterrupted, continuous edge. Such a strong, sharp,
continuous edge is considerably more resistant to cracking
and/or other failure than is a burred edge or a slitted edge
mb/~ 3
: `
~ . . . .
z~
and thus redllces the re~lllLremellt for mLIterlnl at tile
transverse exl:relnit-~es oE ~lle ~astener body to prevellt
cracking or other fni]ure thereof. The tab, extending
from either the outer periphery o~ the Eastener or Erom
the edge of tlle stlld retainin8 aperture, is provided which
mav be gripped by a tool and then pulled to split and
separate the body oE the fastener for selective removal
of the fastener from a retained stud.
Accordingly, it is an object of the present
invention to provide an improved, removable, push-on stud
retaining fastener of the thin walled type.
It is a further object of the present invention
to provide an improved, removable, one-piece, stamped
sheet metal, push-on, stud retaining fastener of the thin
walled type wherein the outer transverse dimensions of
said fastener are minimized.
mb~ - 3a -
.
24
--4--
It is another object of the present invention
to provide an improved, removable, one-piece, stamped
sheet metal, push-on, stud retaining fastener of the thin
walled type wherein the fastener is formed by punching or
5 piercing a hole in a fastener blank and then forming a
dome shaped depression into the blank to obtain the
generally frusto-conical cross sectional shape of the
fastener from the same side of the blank as the hole
punching or piercing operation, the generally dome shaped
lQ depression having an axis generally coaxial with the axis
of the punched hole and wherein a tab is formed which may
be gripped and then pulled to split the fastener for removal
of a retained stud.
These and other objects and advantages of the
15 present invention will become apparent from a reading of
the attached detailed description of the preferred embodi-
ment taken in connection with the attached drawings.
Brief Description of the Drawings
FIG. 1 is a perspective view of the removable
20 fastener of the present invention.
FIG. 2 is a perspective view of an alternate
embodiment of the removable fastener of the present
invention.
FIG. 3 is a cross sectional schematic illus-
25 tration of the first step in producing a fastener inaccordance with the present invention, said first step
comprising partially punching or piercing a hole into the
fastener blank.
FIG. 4 is a cross sectional schematic
30 illustration of the second step in producing a fastener
in accordance with the present invention, said second step
comprises the forming of a generally dome shaped depression
generally coaxial with the axis of the punched hole from
the same side of the fastener blank as the hole punching
35 operation.
--5--
FIG. 5 is a cross sectional illustration of the
removable fastener of the present invention as retaining a
stud in an apertured panel.
FIG. 6 is a perspective view of the removable
5 push-on stud retaining fastener of the present invention
as utilized to retain a stud in an apertured panel.
Descri tion of the Preferred Embodiment
p
Certain terminology will be used in the following
description for convenience in reference only and will not
10 be limiting. The words "up", "down", "top", "bottom",
"upwardly", "downwardly", if used, will designate direc-
tions in the drawings to which such reference is made.
Said terminology will include the words above specifically
mentioned, derivatives thereof, and words of a similar
15 import.
One piece, stamped, sheet metal, push-on stud
retaining fasteners of the prior art and of the present
invention both are, when utilized to retain a cross
sectionally round stud, of a generally annular shape,
20 having a generally centrally located annular stud retaining
aperture, a generally frusto-conical annulus surrounding and
defining the stud retaining aperture and a generally
annular outer flange, the flange being generally perpen-
dicular to the axis of the aperture. These devices are
25 generally thin walled, that is, stamped from a relatively
thin sheet of springy, hardened steel or stainless steel.
The fasteners operate by frictionally gripping the outer
edges of the stud.
The term "stud" as used herein is intended to
30 mean an elongated member of generally constant cross-
section, such as a rod, shaft, bar, wire or the like.
For illustrative purposes only, the fasteners, and studs
retained thereby, illustrated in this description will be
shown as of a generally round cross-section. It is under-
35 stood, however, that the fastener of the present invention
--6--is also intended and suitable for retention of studs
having any cross-sectional shape.
The removable fastener 10 of the present
invention may be seen as utilized to secure a stud, such
5 as a metallic or ceramic stud, extending from an electrical
component or the like, to an apertured panel by reference
to FIG. 6. In a typical application of the present
invention, the electrical lead of an electrical component
is positively retained to a panel or a wire lead or
10 terminal of an electrical component is retained to a
panel prior to soldering thereof by use of the fastener of
the present invention~ The use of such fasteners in
precision miniature and/or microminiature assembly requires
that the transverse dimensions thereof, that is, the radius
15 of the annular flanges, be minimized allowing the studs to
be retained on closer centerlines. It is also desirable
that the fastener 10 be quickly and easily removable
without causing damage to the retained electrical lead or
the like.
In view of the relatively greater cost of electrical
components as compared to the cost of the fasteners of the
present invention, destruction of the fasteners when
removing same to minimize or eliminate damage to the
component during the removal operation is considered
25 desirable.
The methods of producing and the structural ~
features of the improved, one-piece, stamped sheet metal,
removable stud retaining fastener 10 of the present
invention may be seen by reference to FIGS. 1 and 3
30 through 6.
The removable stud retaining fastener 10 of the
present invention comprises a generally resilient body 12
of relatively thin, stamped sheet metal. The body 12
comprises a frusto-conical annulus 14 defining a generally
35 centrally located stud retaining aperture 16 and a radially
2~
--7--
outwardly extending annular flange 18 of transverse
~imension 20. The stud retaining aperture 16 includes a
radially inwardly extending stud retaining edge 22 which
is adapted to engage and retain received studs. As will
5 be discussed in greater detail below, the stud receiving
edge 22 of the fastener 10 is the relatively smooth
continuous edge of a hole punched in the blank used to
produce the fastener 10. Extending radially outwardly
from the stud retaining aperture 16 is a tab 21 which may
10 be gripped by a tool or the like and pulled outwardly
from stud retaining aperture to split the fastener 10 for
removal thereof from a retained stud.
As mav be seen by reference to FIG. 3, the
fastener 10 of the present invention is produced by pro-
15 viding a generally annular blank 24 and then punching orpiercing a centrally located hole 26 therein. As may be
seen from FIG. 4, a forming tool is utilized to form a
generally dome shaped impression 28 in the blank 24 which
provides the fastener body 12 with a generally frusto-
20 conical cross-sectional shape. It is noted that the
generally dome shaped impression 28 is coaxial with the
axis of the punched hole 26. It is further noted that the
forming tool strikes the blank 24 from the top side 30
thereof which is the same side that the punching tool
25 strikes the blank. By forming the generally dome shaped
impression from the same side of the blank as the hole is
punched from, the relatively smooth continuous upper edge
32 of the punched hole becomes the stud engaging edge
rather than the relatively irregular burred edge 34 which
30 is at the bottom of the punched hole 26. Also, as the
dome shaped impression is formed, the relatively smooth
continuous upper edge 32 is stretched which produces a
strong sharp edge 32. The tab 21 is preferably formed
from the material of blank 24 partially severed from the
35 blank by the punch. The tab 21 thus defines a pair of
generally annular surfaces for gripping by a plier or
similar tool.
--8--
FIG. 5 illustrates the removabl~ fastener 10 of
the present invention as assembled to a stud S to retain
the stud S to an apertured panel P while FIG. 6 illustrates
a panel in which a stud is retained by the removable
5 fastener 10 of the present invention.
FIG. 2 illustrates an alternate embodiment of
the present invention in which the removable stud retain-
ing fastener comprises a body 112, a generally conical
annulus 114, a stud retaining aperture 116 and an annular
10 flange 118. A tab 121 extends radially outwardly from the
flange 118 for gripping by a tool and to be pulled upwardly
and towards the aperture 116 to split the fastener 110 for
removal thereof from a retained stud. Except for the
location of the tabs, fasteners 10 and 110 are substanti-
15 ally identical.
Although this invention has been described in itspreferred form with a certain degree of particularity, it
is understood that the present disclosure of the preferred
form has been made only by way of example and that numerous
20 changes in the details of construction and combination and
arrangement of parts may be resorted to without departing
from the spirit and the scope of the invention as herein-
after claimed.
