Note: Descriptions are shown in the official language in which they were submitted.
9~1.
The present invention relates tG a worm-band fastener for fasten-
ing the connection of hoses or the like.
In aeneral, a worm-band fastener comprises an elastic band having
adjacent one end thereof screw-threaded slots, a housing fixed on the
other end of the band and a rotatable worm screw mounted in the housing.
The band end provided with slots is inserted through the front opening
of the housing and engaged with the worm screw to form a loop which
serves to fasten an object, such as a hose. In such a worm-band fastener,
there have been proposed various structures for retaining the housing on
the band but any of them involves some defects which will interfere with
their use.
In brief, prior art devices are di-fficult to assemble, are structurally
weak, and generally ineffective in use. A more detailed discussion of prior
art assemb1y will follow.
Accordinclly, it is an object of the present invention to provicle a
worm-band fastener which can eliminate the above disadvantages associated
with the prior art.
It is another object of the present invention to provide a worm-bancl
fastener which can exert high fastener force by employing a worm screw
housing which is simple in construction anci has high ri~idity.
It is a further obJect of the present invention to provicle a worm-
band fastener in which the worm screw may be smoothly ticJhtenecl.
In accorclance with one embodilllent of the present invention, there is
is provicleci a worm-bancl fastener compYisinc! a worm screw, a band and a
housing for accon~ odatincJ the worm screw -therein. The housincl is fornned
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from a single blank of seamless tubular metal and has integrally formed a
semi-cylindrical portion for accommodating the worm screw and a saddle
portion to be mounted on one end of the band. The bank end on which the
housing is to be mounted is provided with projections for embracing the
front and rear edges of the underside of the saddle portion.
In another embodiment, the housing comprises a tapered semi-
cylindrical portion in place of the semi-cylindrical portion of the first
embodiment and, correspondingly, a tapered worm screw is employed.
The present invention will become more fully apparent from the claims
and description as it proceeds in connection with the drawings.
Figures 1 through 3 are perspective views illustrating various prior
art constructions For retaining a housing on a band in a worm-band
fastener;
Figure 4 is a perspective view similar to Figs. 1 through 3 illustra-
ting the construction according to the first embodiment of the present
invention;
Figure 5 is a front view of the firs-t embodiment of the present
invention;
Figure 6 is a side elevational view of Fig. 5;
Figure 7 is a sectional view taken alony line VII-VII in Fig. 5;
Figure ~ is an enlargeti vertical sèctional view o-f the essential
parts in Fig. 5;
Fi~lure 9 is a sectional view taken along iine IX-IX in Fiy. ~;
Figure L0 is a perspective view of one end of the band;
Figure Ll is a front view of a worm-band fastener accordin~ to the
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second embodiment of the present invention; and
Figure 12 -is a vertical sectional view of the essential parts
of Fig. 11.
An example of such a structure is shown in Fig. 1 in which a saddle
portion 2 of a housing 1 is provided with lugs 3 at the underside 2a
thereof. The lugs 3 are symmetrically bent and extended through an
aperture 5 in the band ~ to retain the housing 1 on the band 4. However,
the structure has not been easy to assemble and yet failed to ensure
consistency in quality. Furthermore, when the worm screw 6 is tightened,
rigidity of the housing 1 becomes insufficient, resulting in spreading
of the folded portion of the saddle portion 2 adapted for holding the
band ~ or lifting of the underside 2a apart from the band ~. These
problems have caused wrenching, tearing and/or twisting of the lugs 3
and consequently, incomplete engagement will result between the thread
of the worm screw 6 and the slots of the band 4 to induce reduced or
inoperative fastening force. If the lugs 3 are made larger, to withstand
higher fastening force. both of -the housing 1 and the band 4 must be Made
as thick and wide as possible, or on the contrary, if the lugs 3 are made
thinner and narrower, crackintJ ancl breaking will result when the housing
1 i s heat treatecl after its formation.
Figure 2 shows another example of such a structure in which the
unclerside 12a o~ -the sadclle portion 12 of the housing 11 is provided wi-th
a trapezoid (as shown in the clrawing) or c;rcular projection 13 and a
perforation 14 which engages the projection 13 in a -form--Fit-ting manner.
Also in this case, insufficient rigiclity of the housing 11 causes the
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same reduced or inoperative fastening force as those in the structure
shown in Fig. 1.
Figure 3 shows a ~urther example in which the underside portions
22a of the saddle portion 22 of the housing 21 are bent toward the centre
line of the band 23 until the respective ends thereof contact one another.
One end of the band 23 is inserted into the saddle portion 22 and then
fixed by spot welding. Such a structure suffers from, in addition to the
defects of the structures in Figs. 1 and 2, the problems that the housing
21 may shift in the longitudinal direction of the band 23 or come off due
to possible incomplete welding.
Referring now to Figs.4 throuah 10 in which the first embodiment of
the presen-t invention is shown, numeral 31 indicates a narrow elastic band
having slots 32 stamped therein at reaul~lar pitches from one end 31a thereof.
The band 31 has ladjacent the other end 131b ~hereof two projections 33 and
34 provided in spaced opposing relationship to each other, as shown in
Fig. 10. The projections 33 and 34 are formed by press bencling, drawing
or like operation along notches provicled in the transverse direction of
the band 31. The band 31 further has an elongated aper-ture 35 disposed
in the loncJitudinal clirection of the bancl 31 between the projections 33
and 34. The slots 32 are alitlned in sequence from the encl 31a of the bancl,
the last one thereof being followed by holes 36a and 36b which are pro-
cJressively smaller in area than the slots 32. Numeral 41 indicates a
housin~cJ which is tightly held between the proJections 33 antl 34 provicled
adjacent the encl 31b of the band 31, and a worln screw 51 is inserted into
the housincJ 41. The housin~ 41 is formed from a single blank of seamless
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tubular metal and has semi-cylindrical p~rtion 42lfor accommodating the
worm screw 51 therein and a saddle portion 43 adapted to be mounted on
the band end 31k which are integrally formed by drawing operation. The
underside 43a of the saddle member 43 has at the front and rear edges
thereof raised corners 43b adapted to be engaged with the projections 33
and 34 of the band 31. The semi-cylindrical portion ~2 has at the front
end 42_ thereof, an end wall 44 provided with a semi-circular guide
aporture 44a to serve as a guide for rotatably supporting the cxtreme end
51a of the worm screw 51.
The worm screw S1 has a shank 52 extending rearwardly from the
extreme end 51a and having screw threads 53. The shank 52 is provided at
the raar end thereof ~ith a shoulder 5~ which is larger in diameter than
the shank 52 adapted to be abutted against the rear end surface of the
housing 41 when the worm screw 51 is inserted therein. A hexagon head 56
is provided through a flange 55 at the back of the shoulder 5~. The
extreme end 51a of th~ worm screw may be formed w;th a peened or up-set
portlon 57 to anlarge the diarneter of a portion extending out of the
guide aporture ~a 90 as to prevant the worm screw 51 from coming out of
tho housing ~1 when the worm-b~nd fastener i5 out of u~e.
Now the oporatlon of the worm-band Ea~tunor thus constructed is as
follows. Tho sacddle portion ~3 oE the hou31ng ~1 is mounted on the end
31b o~ the band 31, thu ralsed corners ~3~. at tho front ancl rear edges of
the undor~ide ~3_ belng ~lttingly placed between the projections 33 and
3~ o~ the band 31. Then the worm screw 51 is in~erted into the semi-
cylindrical portion ~2 Orc the housing, the extreme and 51a being fitted
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into the guide aper-ture 44a of the semi~cylindrical portion 42. Thus
the guide aperture 44a assures smooth positioning and rotation of the
worm screw 51. The band 31 is wound around an object such as a hose and
the end 31a is inserted into -the housing 41 through the front end thereof
between the worm screw 51 and the band end 31b. The hexagon head 56 of
the worm screw 51 is rotated as by a hexagon wrench or the like in the
tightening direction. Then the screw threads 53 are engaged with the slots
32 and, as the worrn screw 51 is rotated, the band 31 is wound up to fasten
-the hose or the like.
During the use of the worm-band fastener, reaction force will be
produced from continued fastening action. Thus the projection 33 of the
band end 31b presses the lower front corner 43b of the saddle portion 43,
and the rear end surface of the semi-cylindrical portion ~2 presses the
shoulder 54 of the worm screw 51. As a result, the housing 41 is pressed
at the rear end surface of the semi-cylindrical portion 42 by the shoulder
54 of the worm screw 51 and the lower front corner 43b of the saddle portion
~3 is pressed through reaction force from the projection 33 on the band
end 31b Furthermore, reaction force will be cleveloped from the band 31
and the worm screw 51 to the side wall of the semi-cylindrical portion 42
and the side wall ancl the underside 43a of the saddle portion 43, and
torsional stress will be procluced on the housing 41 every time torque is
appliecl to the worm screw 51. ~lowever, since the housing 41 has sufficient
rigidity to ensure full tightening oP the band 31, wi-thout causing possible
de~ormation of the housincJ 41 or loose or out of engagelllent of the worm
screw 51. When the -threatls 53 are engaged w;th the sio-ts 32 the crests of
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the threads 53 are projected out of the slots 32 into the aperture 35 of
the band end 31b, resulting in more reliable engagement. As the last slot
32a is followed by the holes 36a and 36b which gradually become smaller,
concentration of stress is prevented, thereby eliminating the possibility
of breakage of the band 31 at the section of the last slot 32a which would
be caused when the band 31 is bent around the hose or the 1ike. The worm
screw 51 having the ex-treme end 51a thereof a hammered portion 57 will not
slip out of the housing 41 while the -fastener is out of use, permitting
ease of handling.
Figures 11 and 12 show another embodiment of the present invention
which is different from the first embodiment in that a housing 61 and a
worm screw 71 are forrned in a tapered confiyuration. Like parts are given
like reference numbers and any further description will be omitted. The
housing 61 is formed by drawing and has integra'lly Formed a tapered semi-
:L5 cylinclrical portion 62 for accommodating the worm screw 71 therein and a
saddle portion 63 to be mounted on the bancl end 31b. The housing 61 is
tightly held between the -two projections 33 and 34. The unclersicle 63a oF
the sadclle portion 63 has at the front and rear edcJes thereof raised
corners 63a adapted to be engagecl with the projections 33 and 34. The
tapered semi-cylindricAl portion 62 has at the front end 62a thereof an
encl wall 6~ provided with a senni-circular guicle aperture 64a For rotatab'ly
supportin$J the extreme encl 71a of the worm screw 71.
The tapered worm screw 71 has a taperecl shank 72 extencling rear-
warclly from the ex-trellle encl 71a ancl having screw threacls 73. The shank 72is provicled at the rear encl thereof with a shou'lder 74 which is larger in
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diame-ter than the shank 72 and adapted to be abutted against the rear end
surface of the housing 61 when the worm screw 71 is inserted therein. A
nexagon head 76 is provided throuah a flange 75 at the back of the shoulder
74. The extreme end 71a of the worm screw may be formed with a hammered
portion 77 as in the case in the first embodiment.
The worm-band fastener thus constructed has substantially the same
operational effect as that of the first embodiment and further permits
smooth tightening operation of the worm screw. In other words, owing to
the tapered semi-cylindrical portion 62 and the forwardly inclining inner
configuration of the saddle portion 63, the worm screw 71 is drawn forward
to therehy exert a pressing force to the tapered semi-cylindrical portion
62 and band end 31b when the worm screw 71 is rotated in the tightening
direction. Now the threads 73 of the worm screw 71 are always maintained
in tight engagement with -the inner periphery of the tapered semi-cylindrical
portion 62 and the slots 32 of the band end 31b, resulting in smooth tight-
ening operation of the worm screw 71.
While the invention has been described with reference to preferred
embodiments thereof, it is to be understood tha-t moclifica-tions or variations
may be easily made without depart;ng from the scope of this invention wh;ch
is cleFined by the appenclecl claims.
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