MULTIPLICATEUR DE COUPLE DE SERRAGE

TORQUE MULTIPLIER ASSEMBLY

Abrégé anglais

ABSTRACT OF THE DISCLOSURE
A torque multiplier assembly that is portable,
compact, and may be easily and conveniently disposed
adjacent a nut, bolt or similar threaded elements to
removably engage the same. The torque multiplier
assembly when so engaged is adapted to exert a first
relatively high maximum torque of predetermined value
on the nut, bolts or similar elements to initially
rotate the same from binding threaded engagement or
perform the final tightening of the nut, bolt or
rotatable element. The torque multiplier assembly is
manually actuated by the use of an elongate torque
wrench of a type that is commercially available and
may be adjusted to supply any one of a number of
maximum torque. The desired maximum torque supplied
by the elongate torque wrench is relatively low,
normally not over fifty foot pounds, and is visually
indicated on a calibrated scale that forms a part of
the torque wrench. The maximum torque supplied by the
torque wrench is transferred to the multiplier assembly
with the torque output of the multiplier assembly being
the torque input of the torque wrench multiplied by a
factor that is inherent to the specific gear structure
of the multiplier assembly.

Revendications

The embodiments of the invention in which an
exclusive property or privilege is claimed are defined
as follows:-
1. In combination with a removably engageable
torque applying wrench, a portable compact torque multiplier
assembly that may be removably disposed adjacent a nut,
bolt head or other engageable rotatable element to removably
engage the same and apply a first torque to the same that
is substantially greater than a second torque that can be
applied thereto by said torque applying wrench, said torque
multiplier assembly including:
a. first and second housing members that have
first side surfaces that are in abutting contact and said
first and second housing members when so disposed cooperating
to define a housing that has a circular opening that extends
transversely therethrough and is in communication with an
elongate opening defined between said first and second housing
members that is tangentially disposed to said circular opening;
b. first means for holding said first and second
housing members together with said first side surfaces in said
abutting contact;
c. a worm;
d. second means for rotatably supporting said
worm in said elongate opening;
e. third means for removably engaging said worm
with said torque wrench;
f. a torque multiplier output shaft centered in
said circular opening and substantially normal to said housing;
g. a worm gear rigidly secured to said output
shaft, said worm gear disposed in said circular opening and in
toothed engagement with said worm, said worm gear rotating
but a fraction of a revolution for each revolution of said

worm;
h. third means centered on said worm gear for
removably engaging said nut, bolt head or element that is
to have said rotational force applied thereto; and
i. fourth means for holding said housing
stationary relative to said nut, bolt head or other element
to permit said nut, bolt head or other element to be rotated
by said third means with said rotational force when said
worm is rotated by said torque applying wrench.
2. In combination with an elongate torque wrench
of the type that has a head, an elongate handle extending
from said head, engageable torque input means on said head,
manually adjustable means on said handle that limit the
maximum torque said torque input means can exert when said
torque wrench and torque input means are concurrently
rotated, a first numbered scale on said handle that is so
operatively associated with said adjustable means as to
visually indicate the particular maximum torque input for
which said torque wrench is set, a torque multiplier assembly
capable of exerting a predetermined maximum torque on a
rotatable element, said torque multiplier including:
a. a shaft of substantial diameter and strength
that is capable of withstanding the greatest of said maximum
torques;
b. a worm gear that includes a cylindrical hub
of less length than said shaft, said hub having said shaft
extending therethrough, said worm gear centered on said
shaft and said worm gear having first teeth on the periphery
thereof;
c. first means for connecting said worm gear to
said shaft to cause said worm gear and shaft to rotate as

an integral unit;
d. a worm tangentially disposed to said worm
gear, said worm including second teeth of spiral configuration
that mesh with said first teeth, said worm gear having
oppositely disposed cylindrical end portions;
e. torque receiving means on said end portions
that removably engage said torque input means;
f. a housing that has a first opening therein in
which said worm gear is disposed and a second elongate
opening tangential to said first opening and in communication
with the latter, said second opening having said worm therein;
g. a pair of laterally spaced first bearing
assemblies, each of said first bearing assemblies including
a first ring-shaped member that engages an exterior end
portion of said hub, a second ring-shaped member that engages
said housing, and a plurality of rotatable elements disposed
between said first and second ring-shaped members;
h. a pair of laterally spaced oil seals mounted
on said shaft adjacent said hub for maintaining lubricant
within said housing;
i. second means for maintaining said oil seals
in fixed positions relative to said housing;
j. a pair of laterally spaced second bearing
assemblies, each of said second bearing assemblies
including an inner race that engages said housing, and a
plurality of rotatable elements between said first and
second races;
k. torque output means on the ends of said shaft
for transferring any desired one of a plurality of maximum
torque outputs to an element that is to be rotated, with each
of said maximum torque outputs being a multiple of one of said
maximum torque inputs; and

1. a second numbered scale on said handle that
is so operatively associated with said adjustable means as
to visually indicate the maximum torque that will be provided
by said torque output means when said torque input means is
in engagement with said torque receiving means and said
torque wrench is actuated to rotate said torque input means.
3. A torque multiplier assembly as defined in
Claim 2 in which said housing is defined by first and second
solid housing portions that are in abutting contact, and in
addition:
m. fastening means for holding said first and
second solid housing portions in said abutting contact.
4. A torque multiplier assembly as defined in
Claim 3 in which said first and second housing portions
have a plurality of pairs of spaced transversely aligned
first and second bores therein, said second bores being
tapped, and said fastening means being a plurality of cap
screws that extend through said first bores to threadedly
engage said tapped second bores.
5. A torque multiplier assembly as defined in
Claim 2 which in addition includes:
m. third means for preventing said housing
rotating when said torque multiplier is applying torque to
a rotatable element through said torque output means.
6. A torque multiplier assembly as defined in
Claim 2 in which said torque output means is a plug of
non-circular transverse cross-section that projects from an
end of said shaft.
7. A torque multiplier assembly as defined in
11

Claim 2 in which said torque output means is a recess of non-
circular transverse cross-section that extends into said
shaft from an end thereof.
8. A torque multiplier assembly as defined in
Claim 2 in which said manually adjustable means is an
elongate member that moves longitudinally on said handle
when it is manually adjusted to provide a desired torque
input from said torque wrench, and the free edge of said
member most adjacent said head when transversely aligned
with graduations on said first and second scales visually
indicating the torque input from said torque wrench and
the torque output from said torque multiplier assembly.
12

Description

11.3~3
The present invention relates to a torque multiplier
assembly that is portable, compact, and may be easily and
conveniently disposed adjacent a nut, bolt or similar
threaded elements to removably engage the same.
The present invention may provide a torque multiplier
assembly that is capable of exerting the same maximum
torque on a nut, bolt head, or other rotatable elementl
as my prior invention described in U.S. Patent No. 3,564,955
entitled "High Torque Wrench Assembly" that was granted on
February 23, 1971, but one that has the operational advantage
that it is more compact, lighter in weight than my prior
high torque wrench, and does not require a torque indicating
device as a part thereof.
The present invention may provide a torque multiplier
assembly that is actuated by a conventional elongate low
torque output wrench that may be manually adjusted to provide
any one of a number of maximum torques and the torque output
of the present torque multiplier assembly being the torque
input of the torque wrench multiplied by a ~actor that is
inherent to the gear structure of the torque multiplier
assembly.
The present invention may also provide a torque
multiplier assembly that is used only when a relatively
torque output is required, and the user of the invention
being free to use the lightweight low torque producing
wrench in its normal manner when not being used to actuate
the torque multiplier assembly.
The present invention may also provide a torque
multiplier assembly in which the torque produced thereby may
be more accurately determined as to the magnitude thereof
than is possible with the torque wrench described in my
previous patent, which prior art invention includes a
torque indicating device of the torsion bar type.
. ~

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FIG. 1 is a perspective view of the invention
fully illustrating one side thereof, and the view also includ-
ing a low torque output wrench used in actuating the torque
multiplier assembly, as well as a stabilizing bar that may
be used to maintain the torque multiplier in a fixed position
relative to the rotatable element to which torque is being
applied,
FIG. 2 is a second perspective view of the torque
multiplier assembly illustratin~ a second side thereof,
FIG. 3 is an end elevational view of the torque
multiplier assembly,
FIG. 4 is a second end elevational view of the torque
multiplier assembly with the torque output element removably
engaging a socket wrench which, in turn, engages a nut or
bolt head of the element that is to be rotated,
FIG. 5 is a front elevational view of the torque
multiplier assembly,
FIG. 6 is a transverse cross-sectional view of the
torque multiplier assembly taken on the line 6-6 of FIG. 5, and
FIG. 7 is a second transverse cross-sectional view
of the torque multiplier assembly taken on the line 7-7 of
FIG. 5.
The torque multiplier assembly A of the present
invention as may best be seen in FIGS. 1, 2, 6 and 7 is actua-
ted by a conventional elongate torque wrench B that has a
head C and the wrench being commercially available. The torque
multiplier assembly A is preferably held in a stabilized
stationary position when imparting torque to a desired rotat-
able element by use of a stabilizing rod D shown in FIG. 1
or other anchoring means.
The torque wrench B includes an elongate handle
-- 2 --

1138693
10 that has a rotatable portion 12 that moves longitudinally
relative the handle as the portion 12 is rotated. The
handle 12 has a first scale 14 over which the free edge
portion 12a of the rotatable portion 12 moves as the handle
10 is rotated. The first scale 1~ has num~ers 14a thereon
which indicate the maximum torque that can be applied to a
rotatable element by use of the head C. Torque wrenches B
of the above-described type are commercially available and
are normally designed to provide not over fifty foot pounds
of torque through the head C. The head C includes a torque
imparting means 16 which may be either a protuberance of
non-circular transverse cross-section or a recess that is
likewise not of circular transverse cross-section. The
torque imparting means 16 as may be seen in FIG. 6 is
adapted to removably engage a torque receiving member 18 as
shown in FIG. 6 that is of non-circular transverse cross-
section, and is a part of the torque multiplier assembly A.
The torque wrench B is of such structure that when the
maximum torque for which it is set is reached the torque
wrench becomes inoperative into far as producing additional
torque.
The torque multiplier assembly A as may be seen
in the drawings includes first and second housing half
portions E and El that have first and second abutting
surfaces 20 and 22. First and second transverse bores 24
and 26 are formed on the peripheral portions of the housing
half portions E and E', with the second bores having threads
on the interior thereof that are engaged by cap screws 28
that serve to hold the two housing half portions in abutting
contact.
The first and second housing half portion~ E and

113E~693
E' have an opening 30 of substantial diameter extending
transversely therethrough, which opening is defined by
first circular side walls-32 formed in the first and second
housing half portions E and E'. The first and second
housing half portions E and E' have an elongate opening 34
therein that is tangential to the opening 30, with the
elongate opening 34 being defined by a second circular side
wall within the first and second housing half portion E and
E'.
A heavy torque output shaft 38 is provided that
has a longitudinal slot 42 therein that is engaged by a key
40, with the key also engaging a radially aligned slot 44
formed on the interior surface of a cylindrical hub 46 of a
worm gear 48 as shown in FIGS. 6 and 7. The worm gear 48
has teeth 50 on the outer periphery thereof.
A pair of laterally spaced anti-friction roller
bearing assemblies 52 are provided, each of which assemblies
includes a number of tapered rollers 54 that rotatably
engage a bearing cup 56 and bearing cone 58. The shaft 38
20 as may best be seen in FIG. 7 has a torque output plug 60
of non-circular transverse cross-section projecting outwardly
from one end thereof and a torque output recess 62 extending
into the shaft 38 from the opposite end thereof.
A pair of oil seals 64 are disposed within the
first and second housing portions E and E' as shown in
FIG. 7 to encircle the shaft 38, with the oil seals being
removably held in position within the housing portion by a
pair of retainer seals 66. A pair of retainer rings 68
are provided that abut against the retainer seals 66, and
30 the retainer rings removably engaging grooves 70 that extend
into the first circular side wall 32. The worm gear 48 is

113~693
held in a fixed longitudinal position on the shaft 38 by a
pair of tranversely spaced retainer rings 67 that engage
grooves 69 formed in the shaft 38.
A pair of laterally spaced, anti-friction ball
bearing assemblies 72 are provided, with each assembly
including an outer race 74, inner race 78 and a numbe~ Gf
balls 76 situated therebetween. A worm 80 is provided that
has cylindrical end portions 82, with each of the end
portions being rotatably supported by the inner races 78
of the anti-friction ball bearing assemblies 72~ The worm
80 and the anti-friction ball bearing assembly 72 as can best
be seen in FIG. 6 are mounted in the elongate opening 34
defined between the first and second housing half portions E
and E'.
A torque receiving plug 18 projects outwardly
from one end of the worm 80, which plug is of non-circular
transverse cross-section. A torque receiving cavity 18
extends inwardly into an opposite end of the worm 80. The
ball bearing assembly 72 as may best be seen in FIG. 6
are maintained in a fixed position within the first and
second housing half portions E and E' by a pair of longitu-
dinally spaced ring-shaped retainers 88 that engage
circular grooves 90 formed in the half housing portions.
Two transversely aligned lugs 92 project outwardly
from the half housing portions E and E' as shown in FIGS. 6
and 7, with each lug having a semi-circular groove 94
extending therethrough, with the grooves cooperating to
provide a first cylindrical opening 96. The first opening
96 may be removably engaged by the stabilizing rod B as
shown in FIG. 1. The pair of lugs 92 also have transversely
and axially aligned second openings 98 therein, which

113~36~3
openings may be engaged by a chain or the like (not shown)
to hold the torque multiplier assembly A in a substantially
stationary position during the time that it is being used
to supply torque through the plug 60 or recess 62 shown in
FIG. 7. In FIG. 4 the plug 60 is shown in removable
engagement with a conventional socket wrench 100, which
wrench 100 is in turn in~engagement with a nut or bolt head
102 to which it is desired to impart a high torque either
in loosening or rotating the same.
The elongate torque wrench B has a longitudinally
extending first numbered scale 14 thereon over which the
rotatable portion 12 moves as the latter is rotated, with
the free edge portion 12a of the portion 12 when transversely
aligned with a graduation of scale 14 indicating the maximum
torque in foot pounds that can be delivered by the torque
wrench B. The gradua~ions 14 have numbers 14a imprinted
on the handle B that indicate the magnitude of the torque.
~ he handle B preferably has a second longitudinal
scale 15 thereon opposite the scale 14, with numbers 15a
of the second scale indicating the torque output of the
torque multiplier assembly A. Each number 15a is obtained
by multiplying the number 14a opposite thereof by the factor
previously described. Once the factor has been determined
it may be used to obtain all of the torque output numbers
on the second scale 15, for the friction between the gears
and bearing assemblies will not vary appreciably over the
entire range of the low torque input to the multiplier
assembly A.
The torque wrench B may be used individually over
the entire low torque range thereof in a conventional
manner. When a higher torque is required the torque multiplier

1~3~3693
assembly A is placed in direct engagement with a socket
wrench as shown in FIG. 4 to apply a desired high torque
to a nut or bolt head 102. The torque multiplier assembly A
is held in a non-rotatable position relative to the nut or
bolt head 102 by use of the stabilizer rod D, or a chain or
restraining element (not shown) that extends through openings
98 and is secured to a suitable anchor. The torque wrench B
is now placed in operative engagement with the multiplier
assembly A, and the wrench portion 12 rotated for it to
move longitudinally on the handle 10 until the free edge 12a
thereof is tranversely aligned with the graduation 15 that
indicates the maximum torque output that will be exerted by
the plug 60 or recess 62 when the torque wrench is exerting
the maximum torque input 14a for which it is set. The torque
wrench B exerts torque on torque multiplier assembly A by
being pivoted upwardly and downwardly relative thereto as
shown in FIG. 4.
The torque multiplier assembly A is illustrated as
having a projecting torque receiving member 18 of non-circular
tranverse cross-section on one end of worm 80 and a torque
receiving recess 18 on the opposite end thereof, each of
which may receive input torque from the torque input member
16 of head C of torque wrench B. The direction of rotation
of torque output plug 60 is controlled by changing the
direction in which torque is imparted to worm 80 by torque
wrench B. From the prior description of torque multiplier
assembly A it will be apparent that lubricant may be d~sposed
within the housing portions E and E', and retained therein
by the oil seals 64.
The use and operation of the torque multiplier
assembly A has been previously described in detail and need
not be repeated.