Note: Descriptions are shown in the official language in which they were submitted.
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The prasent inventor is the inventor o two piece fasteners compris-
ing a grommet and a stud shown in United States Patents Nos. 3,112,547 dated
December 3, 1963 and 3,116,528 dated January 7, 1964 and an initially single
picce nstener shown in Canadian patent application Serial No. 217,~59 filed
January 1~, 1975. Ill each construction the stud moves axially without rota-
t~on in order to secure or release the grommet.
The present invention is directed to fasteners for joining a pair Of
members having mating apertures of polygonal shape. This application is a
division of Canadian patent application Serial No. 248,824 filed March 25,
1976.
An object of the present invention is to provide a fastener compris-
ing a grommet and a stud formed in one piece, wherein after insertion of the
grommet into the perforations, and subsequent severance of the stud, the stud
is axially and rotatably movable relative to the grommet to secure or release
the grommet with respect to th0 perforations.
The fasteners described herein are capable of being inexpensively
formed by a pair of opposing die members without the need of cores.
Accordingly, the fastener of the invention is a single piece fastener
for detachably securing a first member having a quadrilateral perforation to
a second member having a quadrilateral perforation aligned with the perfora-
tion of the first member, said fastener comprising: a. a grommet including a
head having a circular opening therethrough and a pair of spreadable stems
having free-end extremities normally extending in essentially parallel rela-
tion and defining a quadrilateral figure slidably receivable in the perfora-
tions; the extremities of the stems forming, at their confronting sides, con-
verging cam surfaces terminating in confronting, spaced apart bearing faces, ~ -
said cam surfaces being each disposed at an angle to an axial plane of the
grommet; b. and a stud including a head and a shanX attached integrally in a ;
limited area to the grommet head, the stud upon being severed at said
limited area, being movable through the grommet opening and between the stems,
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~056~32
the shank including a stem spreading element having surfaces which form a
minor width and a major width movable into the space between the bearing
faces, the shank having its major width oriented in a direction perpendicular
to said axial plane for axinl movement of the stem spreading element between
tllo bearing faces whereby initial movement o the stud causes the bearing
faco~ to spread without rotation of the stud, the stud upon being severed
having a portion rotatable in said opening and being subsequently rotatable
for alternate placement of the surfaces defining the minor width and the sur-
faces defining the major width in engagement with the bearing faces to release ~ !
or engage the perforation of at least one of the members.
Preferably the stud is provided with a slot to receive a screw- -
driver or similar turning tool, and is also arranged for separable inter-
connecting engagement with a novelly arranged handle.
In the drawings,
Figure 1 is a plan view showing one embodiment of the initially
single piece rotatable fastener, comprising a grommet and stud.
Figure 2 is a sectional view thereof, taken through 2-2 of Figure
1, with portions of the stud shown in side elevation.
Figure 3 is a sectional view of the grommet corresponding to
Figure 2, with the stud inserted therein and turned 90 from the position
shown in Figure 2, the grommet being shown inserted in a pair of perforated -~
members.
Figure 4 is a sectional view of the grommet corresponding to ;
Figures 2 and 3, but with the stud turned 90~ from the position shown in
Figure 3 causing expansion of the grommet; Figure 4 also showing a removable
:. :
turning handle supported by the head of the stud. `
;; Figure 5 is a sectional view taken through 5-5 of Figure 1, with -
` portions shown in side elevation. `
Figure 6 is a further enlarged fragmentary sectional view taken
.
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within Circle 6 of Figure 2~ showing the initial cornection between stud and
grommet.
Figures 7, 8 and 9 are transverse sectional viewstaken through
7-7, 8-8 and 9-9 respectively of Figure 3.
Figure lO is a transverse sectional view taken through lO-10
oE Fi~ure ~.
Figure 11 is a fragmentary side view taken from 11-11 of Figure
4 showing the turning handle in side aspect.
Figure 12 is a further enlarged side view of the handle taken
within Circle 12 of Figure 11.
Figure 13 is an enlarged plan view showing another embodiment of
the initially single piece rotatable fastener, also comprising a stud and a
grommet.
Figure 1~ is a side view thereof taken from 14-14 of Figure 13
showing the stud and grommet in their initial interconnected relation.
Figure 15 is a side view corresponding to Figure 14, but with the
stud inserted in the grommet; the grommet being shown inserted through a
pair of perforated members.
Figure 16 is a side view corresponding to Figure 15, but showing
the grommet expanded to secure the members in to which it is inserted. ; -
Figure 17 is a sectional view taken through 17-17 of Figure 13 ~ ~`
with portions in side elevation, the stud and grommet being shown in their ``
initial interconnected rèlation.
Figure 18 is a sectional view taken in the plane of Figure 17
showing the stud and grommet at right angles to the position shown in -~
Figure 15. ~ `
Figure 19 is a sectionaI view corresponding to Figure 17 and
showing the stud and grommet in the position shown in Figure 16.
: Figure 20 is an enlarged fragmentary sectional view taken within `~
~ ............. . . .
:~. . - . . :
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Circle 20 of Figure 14.
Figure 21 is a transverse sectional view taken through 21-21 of
Figure l8.
Figure 22 is a transverse sectional view taken through 22-22 of
Flgure l9.
Referring first to the embodiment shown in Figures 1 through 12,
the initially single piece rotatable fastener includes a grommet 1 having
a rectangular head 2 including spaced side portions 3 joined by a pair of
connecting webs 4 which are axially offset from each other.
A pair of stems 5 extend from ~he side portions 3 in essentially `
parallel spaced relation. At their junctures with the side portions 3 of
the head 2, the stems are provided with grooves 6 which permit the stems
to flex outwardly from each other. Near their extended ends the confron~ing
inner sides of the stems 5 form converging cam faces 7 which merge into
bearing faces 8, the lower extremities of the bearing faces are provided
with inturned bosses 9. Externally in the regions of the bearing faces and
bosses, the stems form tapered portions 10. Near their JUnCtureS with the
head 2 the stems 5 are provided with a pair of inwardly extending spaced
stud retainer tabs 11.
The fastener includes a stud 12 having a head 13 provided with a - -
cross slot 140 Extending from the head 12 is a shar~ 15 including a circular `~ .
portion 16, having an annular groove 17. Continuing from the lower end of t.
the circular portion 16, the shank forms a pair of diametrically disposed
tapered or converging side surfaces 18 terminating at rectangular end 19.
The narrow edges of the rectangular end 19 are initially joined by frangible
connecting webs 20 to the head 2 of the grommet adjacent to its upper
surface as shown in Eigures 2, 5 and 6.
The fastener is adapted to be received in a pair of perforated
members 21 and 22. The perforations are rectangular and dimensioned to ~ ;
~4~ ;
,.
105~;132
receive the stems 5. The perforation in the member 21 and the thickness of
this member may be such as to interlock with the grommet, once the grommet
is pressed therein, as shown in Figures 3 and 4.
Operation ot` the embodiment sho~m in Figures I through lO is as
fo~:Lows:
Initially the fastener is molded as a single piece. In this
regard it should be noted that the connecting webs 4 and the tabs 11 are
so arranged that the fastener may be cast between a pair of die members
without the use of cores.
With the grommet and stud integrally connected as shown in
Figures 2 and 5, the grommet is inserted in the perforations provided in
the members 21 and 22. Once the grommet is in position sufficient axial
force is applied to the stud 12, to sever the connecting webs 20. It will
be noted that the wide dimension of the rectangular end 19 is in axial ~;
alignment with the cam faces 7 and bearing faces 8. Consequently, when the
stud is initially severed and moved axially without turning, the final
movement of the stud causes the grommet stems 5 to spread as showr. in
Figure 4. The grommet may be subsequently removed from the perforated
member 22 by turnirg the stud 12 from the positions shown in Figure 4 to
the position shown in Figure 3.
During the course of movement of the stud 12 from the position
shown in Figure 2 to the position shown in Figure 4, the shar~ 15 passes
between the retainer tabs 11 spreadirg these tabs, then on continued
movement of the stud the tabs are received in the retainer groove 17.
.. ':
Thus, once the stud 12 has been inserted into the grommet 1, it cannot be
removed, but the grommet may be expanded or contracted by 90 rotation of
` the stud 12.
; Rotation of the stud may be accomplished by a screwdriver or a
coin inserted in the cross slot 14. ~s the fastener may be used repeatedly,
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it is desirable in some cases to provide a turning handle such as shown in
Figures 4, 11 and 12. The turning handle, designated 23, is an essentially
rectangular member having lateral ribs 24 along one margin which are received
in undercut channels 25 provided in the side walls of the cross slot 14.
The cd~e portion of the handle provided with the ribs 24 may be provided
wlth a ~atch finger 26 and an opposed stop 27, as shown in Figures tt and
12~ so that the handle may be readily slipped endwise into place and re-
tained thereon, but may be removed by manually engaging and flexing the
latch finger 26.
Reference is now made to the embodiment of the fastener shown
in Figures 13 through 22. This embodiment includes a grommet 28, the parts
of which are similar to the grommet 1 and similarily identified except as
indicated. In place of the bosses 9, laterally overlappingthe retainer,
bosses 29 are provided. ~ -
Similarily, this embodiment includes a stud 30 the parts of which
are similar to the stud 12, except that the annular retainer groove 17 is ~ ;
,
omitted and the extremity of the shar~ 15 is provided with a s~uare or ~ ~
circular extension 31 protruding beyond the rectangular end 19 and terminating ;
. .
in laterally extending projections 32.
Operation of the embodiment shown in Figures 13 through 22 is
as f~llows:
When the stud 30 is severed from the grommet 28, as in the first
described embodiment, the stud moves axially or downward. During final ~ -
downward movement the projections 32 pass between the retainer bosses 29
to spread the bossès so as to permit the projections 32 to pass. Once the
projections are beyond the bosses 29 the stud cannot be withdrawn from the
grommet, but may be rotated to expand and contract the stems 5 as in the
first described embodiment.
- It will be noted that the major axis defined by the projections
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32 is at right angles to the major aYis of the rectangular portion l9, so
that the initial movement of the stud merely expands the stems 5 temporarily
as indicated by the arrows in Figure t5, subsequent 90 rotation of the
studs being required to secure the grommet as shown in Figure L6. If
doYlred the major axis of the projcctions 32 and the rectangular portion
19 may be in allgnment so that initial securing of the grommet may be
attained with a s:ingle thrusting movement of the stud as in the first
described embodiment.
Having fully described the invention it is to be understood that
the applicant is not to be limited to the details herein set forth, but
that the invention is of the full scope of the appended claims.
