Note: Descriptions are shown in the official language in which they were submitted.
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BACXGROUND OF THE INVENTION ,,
Field of the Invention: ¦
This invention relates to a tool for applying grommets to
a sheet material.
Prior Art:
There are known a variety of grommets made of metal or
plastics to be set in sheet material such as of textile articles.
The grommet usually comprises an eyelet to be pierced through
the sheet material and a washer to be coupled with the eyelet,
în which instance the eyelet is curled or otherwise deformed so
as to fit securely over the washer. This coupling operation
required considerable pressure such that may be provided for
example by a relatively large lever-actuated hand press and hence ¦
is so much tedious.
SU~ARY OF THE INVENTION
Thus, the present inventîon has for its object to
provide a novel grommet-applying tool which is suitable for
setting plastic grommets in a sheet material, the grommets being
~of the design in which an eyelet part is snapped resiliently into
engagement with a washer part.
A more specific~object of the invention is;to provLde a
grommet-applying tool of~he type described which is vexy simple
in-construotion and highly reliable~in operation.
Another specific object of the invention is to provide a
grommet-applylng tool capable of assembllng eyelet part and washer
part of a grommet securely together with a minimum of hand
pressure.
According to the învention, there is~provided a grommet-
applyîng tool for applying an eyelet and a washer to a sheet
material, said tool comprising an elongated cylindrical body
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having at one of its ends a reduced diameter portion and at the
other end a handle portion, a resilient means, a guide pin
movably supported via said resilient means within said cylindrical
body and having at its exposed end a washer retainer portion and
an eyelet retainer portion, and a spring member disposed within
said body and normally biasing said guide pin toward said other
end of said cylindrical body, said washer retainer portion resil- ¦
iently holding the washer to be transferred to and assembled with ¦
the eyelet set in an opening of the sheet material.
Many other advantages and features of the present inven-
tion will become manifest to those versed in the art upon making
reference to the detailed description and the accompanying sheets
of drawings in which a preferred structural embodiment incorporat-
ing the principles of the present invention is shown by way of
example.
BRIEF DESCRIPTION OF THE DRAWINGS
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FIG. 1 is a partly sectional, elevation of a grommet~
applying tool embodying the invention;
FIG. 2 is a plan view of an eyelet constituting one part
1 of a grommet;
¦ FIG. 3 is a plan view of a washer constituting the other
part of the grommet; ;
FIG. 4 is a partly sectional elevation on enlarged scale
of a por~ion of the tool of FIG. 1 shown in operative position;
and ~
FIG. 5 is a cross-sectional view of the gror,~et
showing the same as assembled and~set in a sheet of fabric.
DETAILED DESCRIPTION OP THE PREFERRED EMBODI~ENTS
Referring to the drawings and first FIGS. 2 and 3, there
is shown a kind of grommet 10 which can be applied to sheet
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material by a tool (FIG. 1) embodylng the invention.
It comprises an eyelet 11 made of suitable plastic materiali
such as nylon and having a center bore 11'. The eyelet 11
includes a barrel 12 having on one end thereof an annular flange
13 which is to be retained on one side of sheet material in which ¦
the grommet i9 to be set. The barrel 12 has an annular recess 16
opening radially outwardly and defined by a radial surface 16a,
a slant 16_ spaced axially from the radial surface 16a in con-
fronting relation, and an axial peEipheral bottom surface 16c
extending between the radial surface 16a and the slant 16b. With
the annular recess 16, an annular locking flange 14 is defined
on the other end of the barrel 12, the flange 14 projecting
radially outwardly and having an annular beveled or tapered
surface 15 facing away from the flange 13. Thus, the annular
locking flange 14 is located immediately above the annular recess
16 as seen in FIG. 4. The annular locking flange 14 has an
outsode diameter R which is the same as that of the remainder of
the barrel 12.
The grommet 10 further comprises a circular washer 17
made of similar plastics to that of the eyelet 11, the washer 17
having an annular rib 18 and a plurality (six in the illustrated
embodiment) of locking tongues l9:projecting radially inwardly
from the annular rib 18 and angularly spaced from each other
with a plurality of radial grooves 20 therebetween. The angularly
spaced locking tongues l9 with the radial grooves 20 therebetween
are rendered more flexible or easy snapping action than would
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be the case if the locking tongues l9 were integral with each
other. The locking tongues l9 have arcuate inner peripheral
edges 21 which jointly define a circle having a diameter r that
is slightly smaller than the outside diameter R of the locking
flange 14, so that the inner peripheral edges 21 can ~e held
against the tapered surface 15 of the locking flange 14 when the
eyelet 11 and the washer 17 start being coaxially assembled
together. As shown in FIG. 4, the locking tongues 19 are thinner ¦
than the annular rib 18 so as to be resiliently flexible rela-
tively to the latter. Each of the locking tongues 19 has an
arcuate slot 24 extending adjacent to and along the annular rib
18, and serving to give the locking tongue 19 additional resilient
flexibility. The annular rib 18 has a plurality of protuberances
25 that are angularly spaced preferably at equal intervals and
positioned in radial alignment with the grooves 20 and that
project axially of the washer 17.
The grommet lO is a typical example applicable to the
invention but should not be limited tb the precise form and
construction above advanced which can be assembled by a grommet-
applying tool embodying the invention.
The tool shown in FIG. 1 and generally designated 30
comprises an elongated cylindrical body or tube 31 having a
reduced diameter portion 32 at one or probe end and a handle
portion 33 ~hreadedly engaged as at 34 with the other end of the
tube 31. The tube 31 has an lnner peripheral wall 35 defining
an elongated circular chamber 36 for accommodating therein a
guide pin 37. The gulde pin 37 has adjacent its opposite ends
a pair of annular groove~ 38,39 receiving therein O-rings 40,41,
respectively, which O-rings are fitted in peripheral engagement
with the inner peripheral wall 35 of the tube 31, providing a
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clearance 36' between the guide pin 37 and the wall 35 of the
tube 31. The O-ring 40(41) is made of a suitable resilient
material such as rubber such that the guide pin 37 may be held
resiliently in place within the chamber 36. A spring member 42
is provided in the chamber 36 between the threaded end of the
handle portion 33 and the end of the guide pin 37 adjacent to the 1l
O-ring 41 to normally bias the pin 37 toward the probe end of the ¦
tube 31 or downwardly as viewed in FIG. 1. A peripheral ledge 43 1,
is formed integrally with the wall 35 of the tube 31 to project
radially inwardly, which ledge 43 is disposed for abutting engage-l
ment with the O-ring 40 to limit descending movement of the guide ¦
pin 37. In the position shown in FIG. 1, the guide pin 37 has a ¦
washer retainer 37' exposed beyond the reduced diameter portion
32 of the tube 31, the washer retainer 37' being diametrically
slightly larger than the inside diameter r of the washer 17.
An eyelet retainer 44 is provided integral with the washer
retainer 37' and axially projecting from the guide pin 37, which
eyelet retainer 44 is dimensioned to fit into the center bore 11'
of the eyelet 11. The retainer 44 has an inwardly tapered
portion 44' for purposes to be hereafter~described.
The operatîon of the grommet applying tool 30 will now be
described wlth reference to FIG. 4. The washer 17 is mounted on
the guide pln 37 by:manually fitting:it around tha washer retainer
37' of the pin 37, in which instance the washer~17 is retained
securely because its diameter r is slightly smaller than the
diameter of the washer retalner 37'. The tool 30 thus carrying
the washer 17 is manipulated to pass ~he eyelet xetainer 44
through the bore 11' of the eyelet 11 which has been previously
set in an opening of a sheet of fabric F disposed on a working
bed 45, as illustrated in FIG. 4. The tool 30 is now pressed
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downwardly with the eyelet retainer 44 borne against the bed 45,
so that the guide pin 37 ascends relatively to the body 31 within !
the chamber 36 against the tension of the spring 42. This brings
the reduced diameter portion 32 of the tube 31 with its bottom
end 32~ against the washer 17 and urges the latter to move down
along the washer retainer 37' of the guide pin 37. Further
pressing the tool 30 brings the washer 17 in engagement with the
eyelet 11, in which instance the inner peripheral edges 21 of the !
washer 17 are first brought into contact with the tapered surface
15 of the eyelet 11. ~his causes the locking tongues 19 of the
washer 17 to expand or flare upwardly along the tapered surface
15 and the locking flange 14 of the eyelet to conversely contract
or flex inwardly in contact w.ith the locking tongues 19. To allow
such expansion of the washer 17, there is provided an annular
recess 46 in the bottom of the reduced diameter portion 32 of the
tube 31, and.to allow such contraction or inward flexing of the
eyelet 11, there is provided the tapered portion 44' of the eyelet
retainex 44. Continued descending movement of the washer 17
causes the locking tongues 19 to be snapped over the locking
1ange 14 into the annular recess 16 of the eyelet 11 between the
flange 14 and the fabric F. With the locking tongues l9 thus
trapped in the recess 16, the washer 17 and the eyelet ll are
securely coupled together against accidental separation. The
protuberanceG 25 on the washer 17 bite lnto the fabric F to
fasten the latter securely between the washer 17 and the eyelet
11 as shown in FIG. 5.
The presence of the resilient O-rings 40,41 on the guide
pin 39 permits the pin 37 to move slantingly relative to the tube
31 during assembly of the washer 17 and the eyelet 11, or stated
otherwise, the tube 31 tilts in sliding contact with the O-rings
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40,41 and so does progressively starting with ~reas of least
slide resistance so that the locking tongues 19 can be snapped
into engagement,with the locking flange 14 progressively in the
order in which the series of tongues 19 are more receptive to the ¦
flange 14, and hence much less coupling pressure is required
than would be with the case where the guide pin 37 is directly 1,
engaged with the tube 31, because in the latter case, all of the
locking tongues l9 are subject to uniform pressure to deform
simultaneously, requiring more power to manipulate the tool 30. ¦
Al~hough various minor modifications may be suggested by
those versed in the art, it should be understood that we wish to
embody within the scope of the patent warranted hereon, all such
embodiments as reasonably and properly come within the scope of
our cont ~ution to tile ast.
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