CA1056132A - Initially single piece fastener for securing members having quadrilateral perforations - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A fastener for joining sheet material having aligned quadrilateral apertures includes a grommet and stud. The grommet has a head with spaced side portions and an opening therethrough. A pair of spreadable essentially parallel stems extend axially from the side portions on opposite sides of the opening and define a quadrilateral figure slidably receivable in the perforations. The stud is attached at one end integrally in a limited area to the grommet within the opening and arranged, when severed from the head at the limited area, to move between the stem elements and to rotate thereby to spread the stem elements and lock the grommet in place within the aligned apertures. The extremities of the stems form at their confronting sides converging cam surfaces terminating in confronting spaced apart bearing faces.
The cam surfaces are each disposed at an angle to an axial plane of the grommet. The shank of the stud includes a stem spreading element having sur-faces which form a minor and a major width. The shank with its major width oriented in a direction perpendicular to the aforementioned axial plane is moved axially between the bearing surfaces which are thereby spread apart.
The stud is subsequently rotatable for alternate placement of the surfaces defining the minor width and those defining the major width in engagement with the bearing faces.

Description

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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, :

, :. . ,: . . , -: .

~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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... - . , . ~ .- . . ~ . , . ~ . ............... ., - -.... - ... : . . . .- . : .. : . . ~ . . , . . , , . . . . : , .

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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~ ;

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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.
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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, ~5--,, 1056~3Z :
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.

Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A single piece fastener for detachably securing a first member hav-ing a quadrilateral perforation to a second member having a quadrilateral perforation aligned with the perforation of the first member, said fastener comprising: a. a grommet including a head having a circular opening there-through and a pair of spreadable stems having free-end extremities normally extending in essentially parallel relation and defining a quadrilateral figure slidably receivable in the perforations; the extremities of the stems forming, at their confronting sides, converging cam surfaces terminating in confronting, spaced apart bearing faces, said cam surfaces being each dis-posed at an angle to an axial plane of the grommet; b. and a stud including a head and a shank 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, 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 axial movement of the stem spreading element between the bearing faces whereby initial move-ment of the stud causes the bearing faces 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 surfaces defining the major width in engage-ment with the bearing faces to release or engage the perforation of at least one of the members.

2. A fastener, as defined in claim 1, wherein the stud shank and grommet stems include means mutually engageable upon insertion of the stud shank between the grommet stems to restrain the stud and grommet against subsequent disengagement, but permitting relative rotation.

3. A fastener, as defined in claim 1, wherein the head of the stud is provided with a laterally undercut cross slot and a turning handle having side flanges is slidably received in the cross slot, the turning handle including a stop and latch finger engageable with opposite ends of the slot to retain the turning handle on the stud head.