Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
--1--
Shippin~ and Installation Straps_for Linear Actuators
~e present invention relates to an apparatus and method for
shipping and installing a linear actuator. More particularly,
the present invention relates to shipping and installation
straps for holding in a retracted position the output member
of a linear actuator, such as a hyàraulic actuator, during
transportation and storage and during installation of the
actuator for operation of a mechanism.
llydraulic actuator apparatus are known for operating a mech-
anism at a remote location by way of a master cylinder, for
example, connected to a slave cylinder installed at the remote
location. ~ conduit interconnects the master cylinder to
the slave cylinder, and the hydraulic apparatus is filled with
hyclraulic fluid such that when the piston of the master cylinder
is actuated, the piston of the slave cylinder, and consequently
the piston rod or output member of the slave cylinder, is
simultaneously actuated by displacement of the hydraulic fluid
from the master cylinder to the slave cylinder through the
conduit.
~lore particularly, it is known to provide such hydraulic
apparatus for operating, for example, the release mechanism
oE a ~riction clutch. As disclosed in British pa-tent speci-
fication 1,539,879, it is also known to pre-assemble friction
clutch hydraulic release apparatus, by filling with hydraulic
fluid the master cylinder, the slave cylinder, the conduit
interconnecting the cylinders and a reservoir connected to
the master cy]inder, and bleeding the system before shipment
of the assembly to a motor vehicle manufacturer, for instal-
lation on a motor vehicle. Preferably, the hydraulic
apparatus is filled with fluid maintained by a resilient
diaphragm disposed in the reservoir of fluid, at a pressure
slightly higher than atmospheric pressure to prevent
,~ ,.,
'
~ p~
--2--
introduction o at:mospheric air into the system during
transportation, storage and installation. Pxior to instal-
lation, the piston rod, or output member, projecting from
one end of the slave cylinder may become extended such that
the over-all length of the slave cylinder, with the piston
rod extended, may occupy more space than necessary in the
shipping container, the rod may become bent or damaged while
in transit or storage or become disconnected from the piston,
the pressure of the fluid may drop below atmospheric pressure,
thus causing air to be introduced into the hydraulic appar-
atus and the slave cylinder piston rod must be manually
retracted, and held retracted during installation of the
apparatus in the motor vehicle.
me principal object of the present invention, therefore, is
to provide a restraining strap for the output member of a
linear actuator such as the piston rod of a slave cylinder of
a pre-filled sub-assembly comprising a mastèr cylinder, a
slave cylinder and a conduit interconnecting the maste~r cylin-
der with the slave cylinder. The object of the invention
is achieved by providing a flexible, preferably plastic,
strap having a portion maintaining the slave cvlinder piston
rod in a retracted position by attaching the end oE the
piston rod to the housing of the slave cyllnder, the strap
having appropria-te weakened break-a~ay sections deEining one
or more rupture portions, such that when the piston of the
master cylinder is actuated for the first time, thus causing
a thrust to be applied to the piston and piston rod oE the
slave cylinder, the strap is broken and the apparatus is
enabled to operate in a normal manner.
Another object of the present invention is to provide a
shipping and installation restraining strap more particularly
for the piston rod of a slave cylinder adapted to operate a
--3--
motor vehicle clutch re].ease mechanism having a recess re-
ceiving the end of the piston rod, and to provide a separate
or separable nosepiece for the slave cylinder piston rod end
forming a bearing ~ember interposed between the rod end and
the surface of the recess, and arranged such that the nose-
piece is made integrally with or attached to the bands or
strips of the restraining strap.
A further object of the invention is to provide the bearing-
nosepiece with an integral seal member preventing introduc-
tion of dirt between the bearing surface of the nosepieceand the surface of the recess in the clutch actuating member.
These and other objécts and advantages of the present inven-
tion will become apparent to those skilled in the art when
the following desc.ription of examples of the best modes con-
templated for practicing the invention is read in conjunctionwith the accompanying drawing wherein:
FIG. 1 is a schematic illustration of a hydraulic apparatus
having a slave cylinder, shown partially in section and
provided with an example of structure for a shipping and
installation restraining strap according to the present
invention;
FIG. 2 is a partial vi.ew similar to FIG. 1, but showing the
broken strap ater the first operation of the appara-tus;
FIG. 3 is a front elevation view from line 3-3 of FIG. l;
FIG. 4 is a side elevation view of the restraining strap of
FIGS. 1-3;
FIG. 5 is a plan view thereof as seen from lines 5-5 of
FIG. 4;
'7~7
--4--
FIG. 6 iS a partial view similar to FIG. 1, but showing a
modification of the restraining strap according to the
present invention;
FIG. 7 is a view similar to FIG. 6, but showing the conditi.on
of the strap after operation of the slave cylinder;
FIG. 8 is a side elevation view of the example of strap of
FIG. 6;
FIG. 9 is a plan view thereof;
FIG. 10 is a view similar to FIG. 6, but showing a fur~her
modification of a restraining strap accoxding to the present
1nventlon;
FIG. 11 is a view similar to FIG. 10, but showing the condi-
tion of the strap after operation of the slave cylinder;
FIG. 12 is a view similar to FIG. 6, but showing another
modification of a restraining strap according to the present
invention;
FIG. 13 is a view slmilar to FIG. 12 but showi.ng the condi-
tion of the strap after operati.on of the slave cylinder;
FIG. 14 iS a side elevation view o the restraining strap
of FIG. 12;
FIG. 15 i.s a rear elevation view thereof as seen from line
15-15 of FIG. 14;
FIG. 16 is a schematic illustration of a hydraulic slave
cylinder provided wit~ another example of structure for
~f~
--5--
shi.pping and installation restraining strap according to the
pre,sent invention and shown partially in section;
FIG. 17 is a cross-section from line 17-17 of FIG. 16;
FIG. 18 is a partial section from line ls-la of FIG. 16;
5 FIG. l9 is a partial view similar to FIG. 16 but showing the
broken strap after the first operation of the apparatus;
FIG. 20 is a side elevational view of the restraining s-trap
of FIGS. 16-19;
FIG. 21 is a plan elevation view thereof from line 21-21 of
lO FIG. 20;
FIG. 22 is an eleva-tion view, with portion broken away, of
the rod end nosepiece associated with the .restraining strap
of FIGS`.- 20-21,-
FIGS. 23 and 24 are respectively front and rear views of the15 nosepiece of FIG. 22;
FIG. 25 is a partial view similar to FIG. 16 but showing a
modiication of the restraininy strap accordi.ny to the present
invention;
FIG. 26 is an exploded perspective view of the restraining
strap of FIG. 25;
FIG. 27 is a view similar to FIG. 16 but showing a modifica-
tion of the invention providing a combination restraining
strap nosepiece and seal;
--6--
FIG. 28 iS a partial section along line 28-28 of FIG. 27;
FIGS. 29-31 are respectively side elevation views with por
tion broken away, and front ana rear views of the nosepiece
of FIG, 27;
5 FIG. 32 is a view similar to FIG. 25 but showing a ~urther
modification of the invention;
FIG. 33 is a side elevation view of the restraining strap
of FIG. 32; and
FIG. 34 is a rear elevation view thereof.
Referring now to the drawing and more particularly to FIG . 1,
there is schematically illustrated a hydraulic apparatus
assembly 10 comprising a master cylinder 12 hydraulically
interconnected to a slave cylinder 14 by means of a conduit
16, in the form of a flexible hose, for e~ample. After assem-
bly of the diverse components, the whole appara-tus is filled
with a hydraulic fluid under slight pressure and bled to
remove air from the apparatus by way o a bleed valve 18,
mounted for example on the slave cylinder 14j until all air
has escaped ~rom the apparatus. ~lternatively,~ atmospheric
air is evacuated from the apparatus and the apparatus filled
with hydraulic fluid at a pressure slightly higher than
atmospheric pressure.
An additional reservoir o~ hydraulic fluid, not shown, is
connected to the master cylinder 12. The reservoir of
hydraulic fluid may ta~e the form of a built-in reservoir
integral with, or directly attached, to the master cylinder
housing, or it may be a remotely located reservoir connected
by a conduit to the master cylinder 12. The hydraulic fluid
is maintained during transport, storage and installation at
t~
a pressure sligh tly higher than atmospheric pressure by an
accumulator consistin~, for example, of a resilient dlaphragm
disposed in the fluid reservoir.
As is well known, any displacement of the master cylinder
5 piston rod 20 causes a corresponding displacement of the
piston rod or actuator 22 of the slave cylinder 14, as a
result of transferring a portion o the hydraulic fluid from
the master cylinder 12 through the conduit 16 to the slave
cylinder 14. The piston rod 20, or input member, of the
10 master cylinder 12 may be operated, for example, by the clutch
release pedal 24 of a motor vehicle, the master cylinder 12
being installed, for example, below the floorboard of t:he
motor vehicle driver compartment, the slave cylinder 14 L~eing
attached on the wlderframe of the vehicle in an appropriate
15 position such that the end of its piston rod 22 actuates the
release mechanism 26 of the motor vehicle friction clutch t
not shown.
During assembly of the slave cylinder 14, a shipping and
installation strap 30 is installed, according to the present
20 invention, such as to restrain the slave cylinder piston rod
- 22 from extending beyond a certain limit rom the open end
31 of the slave cylinder housing 32, E'IG. 2. An elas-tomeric
hellows boot 34 has an end affixed to the rim of tlle cylinder
housin~ 32 and another end elastically engaging a portion of
25 the peripheral surface of the piston rod 22 for the purpose
of protecting the covered portion of the piston rod 22 from
the all~bient and preventing introduction of foreign matter
and dirt into the open end 31 of the cylinder housing 32
through ~hich the rod 22 projects. In the structure illu-
30 strated, the end of the rod 22 projecting from the slavecylinder housing 32 has a hemispherical portion 36, provided
with a reduced diameter coaxial projecting pin-like member
38 for en~agement and centering with the end of the clutch
release mechanism 26. The other end of the rod 22 has a
hemispherical enlarged portion 37 freely engaged in a corre-
sponding -tapered hemispherical recess 38 formed at the bottom
of the slave cylinder piston 41.
The slave cylinder housing 32 is provided with a peripheral
annular flange 40, and the strap 30 has a corresponding annular
flange collar 42, comprising an annular flange 43 formed on
one side of a cylindrical rim 44 fitting over the housing
annular flange 40, the strap annular flange 43 forming an
opening 46, FIGS. 4 and 5, fitting over the slave cylinder
housing 32. A pair of diametrally disposed bands or stxips
48 and 50 are heat-welded to, or molded integrally wlth, the
rim 44 of the flange collar 42 at one of their ends and pro-
vided with a nosepiece or retaining men~er in the form of a
partially spherical cup member, 52 and 54 respectively, at
their other end.~ The strap 30 is preferably molded of~plastic-
such as a polyamide (nylon), and the bands or strips 58-50
are relatively flexible. m e strap 30 is molded in the shape
illustrated at F:~GS. 4 and 5, i.e. with a pre-formed bend 56
proximate the end of each band or strip 48 or 50 joined to
the rim 44 of the flange collar 42. ~le o-ther end of each
band or strip 48-50 is providea wi-th a`weakened portion 58
where it is integrally rnolded with the partially spherical cup
member 52-54, each weakened portion 58 being in the form of
a reduced thickness portion as shown at 60, resulting from a
surface groove, most clearly shown at FIG. 4, or a reduced
width portion, as shown at 62 at FIG. 5, or both.
The partially spherical cup members 52 and 54 are each pro-
vided with a central aperture 64 through which passes the
- 9 -
pin-like projection 38 on tlle piston rod end 36, when the
strap 30 is installed during assembly of the apparatus in
the posi~ion ill~strated at FIG. 1, with the partially spher-
ical cup members 52 and 54 disposed over the hemispherical
end 36 of the piston rod 22, such as to maintain the piston
rod 22 in a retracted and centered position.
After installation of the hydraulic apparatus 10 in a motor
vehicle, the first time the clutch release mechanism is
actuated by operating the clutch pedal 24, hydraulic fluid is
supplied from the master cylinder 12, when the piston rod 20
of the master cylinder is reciprocated, to the slave cylinder
14 through the line or conduit 16, such that the slave
cylinder piston rod 22 is extended, for example to the posi-
tion sllown at FIG. 2. Although the weakened portions 58 of
the bands or strips 48-50 of the strap 30 are capable of
holding the slave cylinder piston rod 22 in its retracted and
centered position during shipping, storage and installation
of the hydraulic apparatus 10 in a motor vehicle, the force
exerted on the slave cylinder piston 41 during the first
operation of the clutch release causes the strap bands or
strips 48 and 50 to break away from the C~lp members 52 and
54, respectively, when the piston rod 22 is extended~ thus
subsequently permitting normal operat.ion of l:he hydraulic
apparatus 10.
Although the strap 30 may be molded of any convenient flexible
plastic, polyamide plastic such as nylon type 6/6, for
example sold by E. I. DuPont de Nemours & Co. under the
trademark Zytel has been found particularly convenient/ the
strap bands or strips 48 and 50 having a thickness, for
example of 0.6 to 1 mm, and a width of 8 to 12 mm., with a
break-out groove 60 0.15 to 0.3 mm. in depth and/or a reduc-
tion in width of each band or strip at the junction with the
cup members 52 and 54, as shown at 62 at FIG. 5~ being --
slightly more than one-half the width of the bands or strips
themselves.
t~?-7
--10--
The presellt invention is susceptible of various modifications
for accomplishing its objects of conveniellce of shipping and
installation of pre-filled hydraulic apparatus. An example
of such modification is illustrated at FIGS. 6-9 wherein a
shipping and installation strap 30a is illustrated as com-
prising a single cup-shaped piston rod reta;ning member 70,
disposed over the end 36 of the piston rod 22 of a slave
cylinder 14, FIG. 6, provided with diametrally disposed bands
or strips 7~ each having an integral strut 74 formed on the
end thereof, substantially at right angle to the axis of each
band or strip. The inner end of each strut 74 is.introduced
in a receiving recess 76 formed in an annular flange 78
disposed proximate the end of the slave cylinder housing 32.
A weakened portion 58 in the form of a break-away groove, as
shown at 80, is formed at the junction between the other end
of each band or strip 72 and the cup-shaped retaining member
70 such that, when hydraulic flui.d is fed to the slave cylin-
der 14, thus causing its piston rod 22 to extend, the bands
or strips 72 separate at the ~eakened portions 58 from the
cup-shaped retaining member 70 and free the piston rod 22 for
normal operation, as illustrated at FIG. 7.
In such an arrangement, with the struts 74 relatively loosely
fitted in the receivi.ng recesses 76 in the slave cylinder
annular flange 78, after the bands or strips 72 become
separated from the cup-shaped retaining member 70 in the course
of the first rel.ease of the motor veh;.cle friction clutch,
which generally occurs at the end of the assembly llne, the
bands or strips 72 generally drop off. If they remain
attached to the slave cylinder housing, they do not interfere
with normal operation of the clutch.
At FIGS. 10-11 there is illustrated a further modification
30b of a shipping and installation s-trap according to the
present invention for restraining and centering the output
3~
member of a linear actuator, such as the piston rod 22 of a
slave cylinder 14, in its retracted position ul~til the linear
actuator or slave cylinder, is first operated. The restraining
strap 30b is substantially alike the strap 30a of FIGS. 6-9,
5 the bands or strips 72 being, however, provided on their free
end with a lug 82 snapped through an aperture 84 disposed
in a ring such as the metallic ring 86 slipped over the
cylinder housing 32 and adapted to engage an annular flange
88 on the peripheral surface of an end of the housing 32~
10 t~lhen fluid is first applied, after installation of the hy-
draulic apparatus, to the slave cylinder 14, causing the
piston rod 22 to extend, the weakened portion 58 formed by
the break-away groove 80 at the junction between the bands
or strips 72 and the cup-shaped retaining member 70 causes the
15 bands or strips 72 to separate from the retainin~ member, as
shown at FIG. 11, thus permitting the piston rod 22 to operate
in the usual manner. The loose bands or strips 72 also
generally fall off during first operation of the hydraulic
apparatus.
20 It will be appreciated by those skilled in the art that the
retaining members 52-54 and 70 of the straps 30, FIGS. 1~5,
30a, FIGS. 6-9, and 30b, FIGS~ 10-11, are adapted to restrain
and center the end of a linear actuator output member, such
as the piston rods 22 provided with a hèmispherical portion
25 3G, whether or not the hemispherical portion 36 has a reduced
diameter coaxial projecting pin-like men~ber 38. The strap
retaining mer[bers 52-54, FIGS. 1-5, and 70, FIGS. 6-11, do
not interfere with the operation of the clutch release
mechanism, and they may eventually wear out or fall off
30 without affecting the operation of the clutch release mech-
anism.
A modified restraining and centering shipping and installa-
tion strap, as represented by the example of strap -30c of
FIGS. 1~-15, is particularly adapted for retaining and
35 centering the output member of a linear actuator such as the
s~
--12--
slave cylinder pîston rod 22, FIG. 12, having a cylindrical
end 90 provided with a flat end face 92.` The strap 30c is
substantially alike the strap 30a of FIGS. 8 and 9, i.e. having
a pair of bands or strips 72 terminating each at one end
in an integrally molded strut 74, subs-tantially at right
angle to the axis of each band or strip, having a portion
introduced in a receiving recess 76 in the annular flange 78
formed proximate the end of the slave cylinder housing 32,
FIG. 12. The strips or bands 72 diametrically project from
the edge of a substantially hemispherical retaining member
94, integrally molded therewith and joined thereto by way o
weakened portions 58 each in the form of a groove 80. The
substantially hemispherical retainer member 94 has coaxial
blind bores 96 forming a bottom surface 98 against which abut
the end face 92 of the rod cylindrical end 90, ~Then the strap
30c is installecl with its retaining member 94 placed over
the end 90 of the rod 22, the rod cylindrical end 90 being
introduced into the retaining member bore 96. The retaining
member bore 96 is preferably provided with a plurality of
longitudinal grooves 100, best shown at ~IG. 15, for aid in
installation of the restraining strap 30c to allow air or oil
to escape from the bore 96 when the retaining member 94 is
pushed over the rod end 90.
When the slave cylinder 14 is first operated, the bands or
strips 72 separate or break away from the substantially
hemispherical retaining member 94 at the surface grooves 80
forming the weakened sections 58 of the strap. In the struc-
ture o:E FIGS. 12-15, the substantially hemispherical retaining
men-ber 94 is molded with a substantial wall thickness, and
remains in position, as shown at FIG. 13, during operation of
the clutch release mechanism. The peripheral surface of the
retaining member 94 actually forms a spherical bearing inter-
posed between the flat end face 92 of the piston rod 22 and the
end of the clutch release control member 26.
3~ 7
-13-
~eferring now to FIG. 16, there is illustrated a slave
cylinder 114 having a housing 132 atkached to a bracket 135,
or other member, forming part of the clutch bell housing or
transmission housing, not shown. The end 136 of the slave
cylinder piston rod or actuator 122 is engaged in the central
bore 137 of a separate nosepiece 138 forming a bearing
member between the rod end 136 and a generally hemispherical
recess 139 in the clutch release lever 128. A strap 130,
together with the nosepiece 138, forms a restraining means
for the piston rod or actuator 122.
m e slave cylinder housing 132 is provided with a peripheral
annular flange 140, and the strap 130 has a corresponding
annular flange collar 142, FIGS. 1~ and 21, comprising an
annular flange 143 formed on one side o a cylindrical rim
144 fitting over the housing annular flange 140, the strap
. .
annular flange collar 142 forming an opening 146 itting over
the slave cylinder housing 132. A pair of diametrally disposed
bands or strips 148 are molded integrally with the annular
flange 143 at one of their ends and provided with an integral
bar or strut member 150 at their other end. The strap 130 is
preferably mo]ded of plastic such as a pol~amide (nylon),
and the bands or strips 148 are rela-tively flexlble. The
strap 130 is molded in the shape illustr~ted at FIGS. 20 and
21, i.e. with a pre-~o~ned bend 152 p1-oxin~ate the end of each
band or strip 148 joined to the rim 144 of the annular flange
collar 142. Preferably, a plurality of small projecting nibs
154 are formed on the inner surface of the cylindrical rim
144 for providing a relatively tight elastic fit of -thc cylin-
drical rim 144 of the annular flange collar 142 over the
slave cylinder flange 140. The other end of each band or
strip 148 is provided with a weakened portion 158 where it
is integrally molded with the bar or strut member 150, each
weakened portion 158 being in the form of a reduced thickness
7'7
-14-
portion as shown at 160, resulting from a surface groove, most
clearl~ shown at FIG. 20l or a reduced width portion, as
sllown at 162 at FIG. 21, or both.
The nosepiece 138, as best shown at FIGS. 22-24, is in the
form of a cylindrical cap having a generally cylindrical body
164 provided on one end with a generally hemispherical face
portion 166 and on the other with a flat annular end face 168
through which is disposed the bore 137. The bore 137 is pro-
vided with a plurality of longitudinal grooves 170 on its
surface, such as to facilitate introduction therethrough of
the end 136 of the slave cylinder piston rod 122, the bore
137 terminating in a flat surface 172 against which the face
o the end 136 of the piston rod 122 normally engages when
the nosepiece 138 is installed over the piston rod end. A
pair of s~mmetrically disposed bifurcated ears 174 integrally
radially project from the cylindrical body 164 of the nosepiece
138 proximate the annular end face 168 thereof, and each
bifurcated ear 174 is provided with a partially cylindrical
notch 176 forming a hook for attachment thereover of the bar
or strut member 150 at the end of each band or strip 148, the
reduced width portion 162, for exc~lple, of the band or strip
148 being disposed within the bifurcation gap 177 of each
bifurca-ted ear 174, as shown at FIGS. 16 and 17. The nose-
piece 138 may be made of the s~le Material as the strap 130,
or of a different material and, if so desired, it may be made
of metal. ~hatever the material used for making the nosepiece
138, it is so dimensioned that its hemispherical end face 166
fits within the partially spherical recess 138 in the clutch
release lever 128, such as to provide a generally swivelling
3~ connection between the slave cylinder piston rod 122 and the
clutch release lever 128. The swivelling connection compensates
3~
-15-
for relative inaccuracy in alignment of the diverse elements,
and allows pivoting of the clutch release lever 128 during
operation of the clutch mechanism, the hemispherical end
face 166 of the nosepiece 138, and the partially spherical
recess 139 co-operating for forming a ball and socket bearing
arrangement between the end 136 of the piston rod 122 and the
clutch release lever 128.
After installation of the hydraulic apparatus in a motor
vehicle, the first time the clutch release mechanism is
actuated by operating the clutch pedal, hydraulic fluid is
supplied from the master cylinder, when the piston rod of
the master cylinder is reciprocated, to the slave cylinder
114 through the line or conduit 116, such that the slave
cylinder piston rod 122 is extended. Although the weakened
portions 158 of the bands or strips 143 of the strap 130 are
capable of holding the slave cylinder piston rod 122 in its
retracted and centered position during shipping, storage and
installation of the hydraulic apparatus in a motor vehicle,
the force exerted on the slave cylinder piston during the
first operation of the clutch release causes the strap bands
or strips 148 to break away from the bar members 150, FIG.
19, when the piston rod 122 is extended, thus subsequentl~
permitting normal operation of the slave cylinder 114.
An example of further modification of the invention is illu-
strated at FIGS. 25-26 wherein a shipping and installation
strap 130a is illustrated as comprising a ring 178 disposed
over a separate cup-shaped piston rod retaining member or
nosepiece 138a placed over the end 136 of the piston rod 122
of a slave cylinder 114, FIG. 25. The cylindrical body por-
tion 164 of the nosepiece 138a has a radially extending
annular flange 180 engaged with the rear of the ring 178.
The ring 178 is provided with diametrally disposed bands or
strips 182 each having an integral strut 184 formed on the
~,~s)~
-16-
end thereof, substantially at right angle to the axis of
each band or strip 182. The inner end of each strut 184 is
introduced in a receiving recess 186 formed in the annular
flange 140 disposed proximate the end of the slave cylinder
housing 132. A weakened portion 158, for example in the
form of a break-away groove, is formed at the junction
between the other end of each band or strip 182 and the ring
178 such that, when hydraulic fluid is fed to the slave
cylinder 114, thus causing its piston rod 122 to extend, the
bands or strips 182 separate at the weakened portions 158
from the ring 178 and free the cup-shaped nosepiece 138a,
and consequently the piston rod 122, for normal operation.
It can be seen that in this modification of the invention,
the nosepiece 138a also acts as the ball portion of a ball and
socket bearing member interposed between the end 136 of the
piston rod 122 and the clutch release lever 128 provided with
a generally hemispherical recess 138 engaged by the hemispher-
ical end 166 of the nosepiece 138a.
The structure illustrated at FIG. 27 comprises a retaining
strap 130b identical to the restraining strap 130 of FIGS
16-21 combined with a modified nosepiece 138b having a disc-
like sealing member 190 integrally formed therewith and
projecting in a flange-like fashion from the cylindrical body
portion 164 of the nosepiece 138b, and provided with a toroidal
integral rim 192. ~s best shown at FIGS. 29-30, the disc-
like sealing member 190, in a relaxed state, is slightly
dished towards the hemispherical end face 166 of the nosepiece
138b, such that when the slave cylinder 114 is installed in
a motor vehicle for actuating the clutch release lever 128,
3Q FIGS. 27-28, the toroidal rim 192 is urged in engagement with
the surface of the clutch release lever 128 around the peri~
meter of the generally hemispherical recess 139 in which is
engaged the hemispherical end face 166 of the nosepiece 138b.
The disc-like sealing member 190 thus~forms an effective seal
~3Lo~ 77
-17-
preventin~ the introduction of dirt from the ambient and the
surroundings between the bearing surfaces formed by the
surface o the hemispherical end face 166 and the generally
hemispherical recess 139, which could cause rapid wearing of
the bearing surfaces in engagement.
As illustrated at FIGS. 32-34, restraining straps of the type
disclosed herein, that is comprising a nosepiece, such as the
nosepiece 138c, formed integrally with the strap 130c, may
also be provided with a disc-like sealing member 190 formed
integral with the nosepiece 138c and radially projecting from the
cylindrical body portion 164 of the nosepiece. In the struc-
ture illustrated at FIGS. 32-34, the retaining strap portion
130c of the integral assembly has the general structure com-
prised of bands or strips 182 provided at an end each with a
14 strut 184 enga~ed in an appropriate recess 186 in the flange
140 of the slave cylinder housing 132. The other end of each
band or strip 182 is integrally attached to the nosepiece 138c
by a weakened portion 158, for example in the form of a
reduced width portion, such as to readily separate from the
nosepiece upon first actuation of the slave cylinder 114.
After separation of the nosepiece 138c from the bands or
strips 182, the nosepiece acts as a bearing member interposed
between the end 136 of the piston rod 122 and the recess 139
in the clutch release arm 128, the flexible disc-like sealing
member 190 frictionally sealing the bearing suraces against
any dirt from the surroundings.
It will be appreciated by those skilled in the art that the
present invention, although disclosed for illustrative pur-
poses in specific structures in conjunction with a specific
hydraulic apparatus, has many practical applications in ship-
ping and installing diverse linear actuators of any form
whatsoever wherein it is desired to restrain against displace-
ment the actuator output member until after installation, and
-1.8-
to free the output member for nol~nal operation upon first
actuation.
~aving thus described the present invention by way of examples
of structure thereof, modifications whereof will be apparent
to those skilled in the art, what is claimed as new is as
follows:
