Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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2132943
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~AL~ NttT CAPABL~ O~ ~NGAGIN~ 5BIL~EN~L5r ANC~HER ~:
H~L~ NUT ~ :
U~XGP~OUND O~ THE ~EN~ IN -
1. FI~LD OF q'HE INVEN'rION
This inventlon relates to a half nut, more
p~rticularly to a halP nut which is oapable of enga~ g
resiliently anothRr half nut so as to form a nut member
~or fast~nin~ ob~ect$ together with a threaded bol~. : ';
2 . DE~S~RIPTION OF THE R~A~EI~ ART '
AcGordintJ to th~ U. S. Pat. No. 5,248,23~, ~here ~ ~:
is disclosed a nu~ and ~olt fiet which includes a nut :
member havin~ two halve~ and a threaded bolt en~agea~le
with the two halves. The combination o~ the. two halves ' ; .
togethqr with the threaded bolt provides a lo~cing
m~c:hanism which does ~ot easily get loose when an
external force ~ applied th~reon~
.
SU~l~Y OF THE YNv~ 5 IC~N - ::
l'he main object of ~he present invention is to ~ ~;
improve the ~tructure of one of the half nut6 of the ;~ ':
nut mem~er so that a r~ilien~ abutting enyagement ~ ;
l~etween the hal~ nllt can be achieved when the halî nuts
~re used to fasten objects together with a threaded : ~.
I~ol'c .
Aocordingly, th~ half nut ~f this inventi~r~ h~s a
2~ sho~t ~hank with an external screw thread th~reon, and
an inner ~all which con~ines an axial bore..'
~he~ethrouyh. The inn~.r wall of the half nut has an ~ ; :
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2132943 ~ ~
internal s~rew thread with a ~ir~t scr~w pit~h. The
e~ternal screw thxead of the hal~ nut has a ~econd
~rew pit~h dif~erent from the first sorew piteh. The
internal and external screw threads of the hal~ nut axe
suh~tantially concentri.c with e~ch other. The external
~~crew thread of the hal.f nut is de.~ined l~y
~ub~tanti~lly constan~ major and minor radii, while the
internal s~rew thread is def ined by substantially
aonstant gre~test and shorte~t radii. ~he internal
~crew thread of the half nut has ~ constant half~
breadth whieh i~ greater than a differen~e between the
minor and ~reate.~t radii.
In the di~clos~d e~bodiment, the fir~t screw pit¢h
o~ the internal ~crew thread o~ the half nu~ is grea~er
than the second screw pitch of the external ~rew
thread of the half nu~
In one çmbodiment, the minor radius of the exte~nal
. . . ..
s~rew ~hread i~ ~rea~er than the ~reatest radi~s of the
in~ernal ~raw ~hx ead .
In ano~her embodiment, the yreates~ r~dius o~ the
intern~tl ~crew thre~d is greater than the. mino~ radius
of the external sc~ew threAd.
The h~lf n~lt o~ ~hi~ irtve.ntion ~oope~tes wlth ~;;
an~thRr half n~t and a threaded holt to fo~nt a fixin~
~5 means which consequently provides a resilieht abutting
en~agement when ~he fixin~ me~ns is used ~o fA~t~n
ob;ect~ toqether. --
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BRIEP D138CRXPq'ION C)P q~ltE DRP~WI;NG~
O~her feature~ and advantages of the present
invention will bec~me n~ore ~ppa~eh~ in the followi.ny
detailed descripti~n of the preferred embodiment with
referen~e to the accompanyiny drawings, in which~
Figures l~A) and l(B) ~how cro~ sec~ional viçw~ of
~o halves o~ ~ nLlt nlember 0~ tlle presen~ in~ention;
Figure 2 i.s ~n enlarged view of the Gircle "F"
shown in Fig~
Figure 3 ~how~ the half nut of ~he present
inv~ntion when cooperating with a threaded bolt to
~a~ten objects together;
Figure 4 shows the half nut of the present
1nvsntion when coop~r:ating with the threaded bol~ and
an~ther hal.f nut ~f the nut mt~mher to fasten two
ob~ats toyether;
Figure 5 illustrat~s the direction~ of force~ which
are pre~ent in the two halves of the nut memher after
two objec.~s have behn ~astened together with the u~e of
a o the Bame
Fi~ure ~ ~how~ ~nother preferred em~odiment o~ the
hal~ nut. ~f t},~ present invention together With another
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lla 1 f nut; and ~ '
Fig~lr~ 7 ~how. ~he anothe~ preferred embodiment of
the pre~ent invention when cooperating with the ;
~hreaded bolt ~nd another half nu~ of the nut member.
: DE~AI~E~ DE~CR~PTION OF THE PR~FE~RED EM~ODIMEN~
CA 02132943 1998-0~-27
Referring to Figures l(A) and l(B), a fixing means
includes a nut member and a threaded bolt to be inserted
threadedly in the nut member. The nut member includes a first
half 1 and a second half 2. The first half 1 includes a short
shank 12 with a predetermined iength L1 and an external screw
thread 120 thereon, and an inner wall 13 which confines an
axial bore therein and which has an internal screw thread 130
with a first screw pitch. The external screw thread 120 of the
first half 1 has a second screw pitch which is different from
the first screw pitch of the internal screw thread 130, and the
internal and external threads 120, 130 are substantially
concentric with each other.
The second half 2 has a threaded bore with first and
second sections 210, 220 of differing radii. The second
section 220 is narrower than the first section 210 which has
the first screw pitch. The second section 220 has the second
screw pitch. The first section having the first screw pitch
is engageable with the external screw thread 120 of the first
half 1.
Referring to Figure 2, the external screw thread 120 of
the first half 1 is defined by a substantially constant major
radius dl which is a vertical length between the dotted line
"P" and the axis "C" of the first half 1, and a substantially
constant minor radius d2 which is a vertical length between the
dotted line N and the axis "C". The internal screw thread 130
of the first half 1 is defined by a substantially constant
~ ~~5-~ 2~32943
~reatest raclius d3 which iB a ver~ic~l length ~etWeen ~ ~:
the dotted line "M~ and the axis ~ o~ the ~irst half
1, and a sub~tantially eonstant shortest radius d4 ~ :
whi~h is a vertiaal length between th~ dotted line "Q"
and the axis ~C" of the Pirst h~l~ 1. The minor radius
d2 o~ the external screW thread 120 o~ the first half 1 -~
is gre~e~ t}lan the greates~ radiu~ d3 oE ~he internal -~-
s~r~w thread 130. ~he internal screw thread 130 has a
, -, ~,
constant half-breadth "X" which is ~e~ter thAn a
differe~lce ~Y" between the minor and yreatest r~dii
d2, d3. The ~vn~ant half-hread~h "X" is a ~ross-
sec~ional width whiGh is measured ~t h~lf of a vertical
heiyht between a tip point and a ~ottom of the internal
scrsw thread 130, i. e. hetween the dotted lines "M~
ancl "~ he dott~d line "M", whi.ch is drawn
horizon~ally at ~he dis~A1 end points of tlle grea~e~t
radii d3, i9 nearer to the axis IIC'I when compared to
~ht~ dotted line ~N~ Which is drawn hori~ontally at the
di6tal erld polnts o~ the mino~ radii d2. :
2C ~eferring to FicJ. 3, when in use, ~he threaded bolt
~ is insertsd through two objeats 90, and the ~irst ~.
half 1 is screwed onto the ~hrea~ed bolt 3. A wa~her
31 ~an.be provided between the ~ir~t h~lf land the
o~eat~ 90. Note tha~ the first screw pitoh of the
~5 interna.l screw thread 130 i5 greate~ ~han the second
screw pit~h of ~he external screw thread 120 o~ the
first half 1. ~he threaded ~lt 3 has the ~me pitch
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~s the internal screw thread 1~0 of the ~irst half 1
such th~, when the latter is ti~htened relative to the
former, an axial ten~ and compression force is
generated be~ween ~he threaded bolt 3 and the internal
screw ~hread 1~0 o~ the first half 1. ~he force
correspondingly cau~es ~he ~hreaded bolt 3 and the
first half 1 to move in opposed directlons ~rom th~
o~jeots 90, thereby fastenlny the lat;te~. ~o~e that,
sincq the head portion 11 of the l~irst halP 1 has a
thickne~s whi~h is gr~ater than the ~han~ l~ and
therefore possesses a greater strength, deformatiol1 of
the thread withirl the ~hank 12 is more severe th~n th~t
within the head portion 11. The dotted circle (A)
suf~ers the greatest thread deformation while the
dotte~ circle (C) suf~rs the leas~ ~hread deforma~ion.
The shank portion ~2 of the firs~ half l, beincJ weaker
than thb head portion 11, is corr~pondingly compre~sed
axially, whe~ein the shank portion 12contracts such
that it pos~esses a length L2 which is shorter than the
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length L1, ~s shown in FicJ. 1.
Refe~ring to Figur~ 4, the ~econd half 2 is
tightened on ~he ex~ernal s~'rew thread 120 of the first
hal~ e~ause ~he ~ir~t and second sections 210, 220
hava di~ering screw pi~ches, and since the screw pitch
~ the second section 220 is greater than the screw
pitc~ of the firs1: seotion 210, a ~ull turn of tne
s~cond half 2 ~auses t~e second section 220 ~ move a
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CA 02132943 1998-05-27
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full leng~h of its ~c~e~ pitch while the first section
210 moves a lenqth g~eater that its screw pit~h,
thereby compressing the first sec~lon 210 of the ~econd
half 2 ~arther ~oward ~he first half-l. Thus, the
short 5hank 12 of the first half l is compressed
axially by the rotation of the second half 2 ~elative
to ~he shank 12 o~ the first half 1 su~h that the
length of the shank 12 shorten~ to L3 which is shorter
than the length L2 of the shank 12 bafore the second
o half 2 is threaded thereon. Unde~ such a condi~ion, a
resilient abu~ting engagement is generated bet~een the
external s~rew thread 120 of ~he first half 1 and the
second section ~20 of the second half 2 due to the
thickness reduction at the shank 12. The portion in:
the dotted circle (c') suffers ~he most seve~e thread
deformation while the portion in the dotted cir~e (A')
suffers the le~st thread deformation. ~ote that the
forces whi~h are generated by t~e firs~ and second
halves 1, 2 after the fi~st half 1 has been threaded on
the threaded bolt 3 and the ~econd halr 2 has been
threaded on the shank 12 of the first half ~ are
counter-balanced s~ch that they provide f irm engagement
- between the ob j ects 90.
. Referring to ~ig . 5, note that the objects 90 are
engaged stationarily after the first half 1 is
tightened on the thre~ded bolt 3. Under this
condition, the threaded bolt 3 causes a compression
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force (P) on tlle o~e~ts ~0 which is countere~ by the
force (Pl) gen~trateà bet~een the first half ~ and the
~hreaded ~ 3. When t}~e second half 2 i~ ti~htened
relative to the sh~nk 12 of tl~e fir~;t half 1, an axial
~ompre~sion foroe (Ps) i~ produeed betwee.n the external
gcrew thread 1~0 of the fir~t half 1 and the first
:3ection 210 of ~he ~ec:ond h~l~ 2. ~hen the objects 90
are at a stativna~y position, the compression ~orce
(P~) is equi~a~ent to th~ compression f~-ce (P1) which
is produ~ed by th~ ~irst half 1~ In case ah external
~orce which is çlreater than (Ps) is appliecl on the
fas~ened objecl~s 90, the force (P1) serv~s as a
compensating force to prevent the fastenecl obje~t~ 0)
~rom 1~ing mavecl.
. .
lS Re~erri.ng to ~igure 6, in another preferred ~ .;
embodiment, ~he half nut has an external screw thread
520 for~ned on the short ~hank 52 and an i~ernal sorew .; .
thread 530 formed on an inner wall surf~e whicn
~on~ine~ an axial bore th~rethrough. The internal ; ~
sar~w th~ead ~3û has a constant half-b~eadth (T) which '. :-
i9 greater ~han the differehce (S) be~ween t}le minor ~.'.
and greatest diameter~ d5, d~. In this embodiment, ~he ~.
greatest cliam~ter jd5 of the internal ~cr~w thread $30
is greater than the minor diamete~ d6 of the external
~5 scre~ thread 520. Tllus a thic};ness bet~Je~n the
internal and external screw threads 520, 530 is
aaaordingly redu~ed so the tips o~ the internal and
CA 02132943 1998-05-27
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external screw threads 520, 530 closely overlap with
- one another.
n ~se, the threaded bolt 7 is inserted through the
- first half 5 and the second half :6 is th~eaded on-the
latter such that an axial tensile and compression force
is generated between the in~ernal screw thread 530 and
the threaded bolt 7 ~t the positions (H) and (I). When
the second half ~ i~ sleeved so as to be tightened on
the shank 52 of the firs~ half ~, an abutting
engagement is generated at the position ~G), an axial
tensile and compression ~orce is generated at the
position (K), while a ~esilien~ abuttiny engagement is
. generated at the positions (~) between the external
screw thread of ~he short shank 52 of the first half 5
and the internal screw threa~ of the f irst section 61
of the second half ~. Therefore, the engagement
provided by the half nut 5 of the present invention
is f irm.er than tha~ disclosed in the previously cited
U. S. Patent.
As explained above, the i~proved ~tructure o~ the
first ha-lf 1 o~ the nut me~be~ pro~ides a resilient
abutting engagement in cooperation with the s~cond half
2 and the th~eaded bolt 3. Thus, the ob~ec~s
90fastened by the nut-and-bolt set which includes the
hal~ nut 1 of the present invention is firmer when
compared to the conventional nut and bolt set.
With the invention thus ex.plained, it is obvious
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2132943 : :~
to t~ose s~.illed in the art th~t v~rious modific~tions
and variations can be madR wit~lout departing from the ~;
scope and spirit thereof. It is therefore intended
that this invention be limited only as indicat~d in the
appended claim~
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