Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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SLIDING SEA_OCK ASSEMBLY
FIELD OF THE INVENTION
This invention relates to a sliding seat lock
assembly particularly adapted Eor use in association
with support means such as those described in
Canadian patent application No. 494,975 filed on
November 8, 1985.
DESCRIPTION OF PRIOR ART
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Devices which use ~rictions to lock a part in
position on a rod or other longitudinally extending
member are known.
For example, in U.S. patent No. 3,749,345 (Luder
et al) there is disclosed a rod supported shower
slide ~ith an eccentrical clamp which includes a
sliding body having a pin which carries an eccentric
having a curvature corresponding to the curvature o~
the rod upon which the device is engaged. rrhe pin i5
adapted to be rotated to cause the eccentric to enter
into holding engayement with the rod.
U.S. patent No. 3,995,963 (Mosley et al)
discloses a sliding arm lock assembly, particularly
adapted for use in a cardiac compressor, which
comprises a locking member positioned within an
opening in the arm and is likewise engageable with a
post and slidable jointly with the arm along the axis
o~ the post to initiate a clamping ~orce. A shaft
having a handle assembly on one end is threadable in
the locking member and hand ro-tatable to move the
locking member laterally relative the post to secure
the arm and post together at selected position
relative to each other.
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Another example is shown in U.S. patent No.
29~,625 which discloses a glb operated by a pinion
arm, for locking a saddle supporting a rock-drill in
place on a post.
However, all of these devices require
untightening and retightening when used. These
operations require time and attention from the user.
OBJECTS OF THE INVENTION
An object of this invention is to provide a
sliding seat lock assembly which is fast and easy to
operate.
A second object of this invention, is to provide
a sliding seat lock assembly which does not require
-the application of force to lock the seat on the
post.
Another object oE the invention is to provide A
sliding seat lock assembly which makes use oE the
users weight to increase the holding capacity oE the
seat.
In accordance with the present invention there
is provided a sliding seat lock assembly which
comprises means (which in the preferred embodiment ls
a cam having a surface chosen for its frictional
properties), a supporting member or post also covered
with a material having a high coefficient of friction
and a base to support the seat and said means.
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BRIEF DESCRIPTION OF THE DRAWINGS
In order that the lnvention can be understood
and readLly carried into effect, and so that the
above-mentioned objects will become apparent, a
sliding seat lock assembly in accordance with the
present invention will now be described by way of
example only, with reference to the accompanying
drawings in which:
figure 1 is a perspective view of a seat or
support on which an embodiment of the invention is
mounted;
figure 2 is a side view of the sliding sliding
seat lock assembly shown in figure l;
figure 3 is a side sectional view (along line
3-3) of the sliding seat lock assembly shown in
figure 5;
fi~ure ~ is a top partially sectiona:L view of an
embodiment oE sliding seat :I.ock assembly in
accordance~ w:Lth the invention;
figure 5 is a rear partially sectional view of
an embodiment of sliding seat lock assembly in
accordance with the invention.
DESCRIPTION OF A PREFERRED EMBODIMENT
Referring now specifically to the drawings, a
seat supporting assembly 1 comprises a seat 30~ a
support member 20 and a sliding seat lock assembly 10
having a base or casing 40, a cam 50, two (2) guide
rollers 70 and two (2) handles 60.
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The casing 40 has two (2) side portions 42 and
one (l) back portion 43. A seat 30 is pivotally
attached to the upper section of back portion 43 by
means of shaft 32. Further, a spring 33 allows seat
30 to automatically return to the upright position.
Side portions 42 have a triangular shape and
comprise means to support the cam 50 and the guide
rollers 70.
Cam 50 comprises a shaft 53 on which a body 52
having an involute shape, and two wheels 55 are
secured Further, the body 52 is provided with a
Erictional surface 54. The shaft 53 extends outwardly
from both side portions 42 to support a pair of (2)
handles 60, one at each end, which allow cam 50 to be
rotated when they are rotated.
The handles 60 comprise a body 62, a covering 63
and a pin 64 which secures the body 62 to shaft 53,
and a spriny 65 biaisiny the cam 50 in a position
such that a portion of cam 50 is in engayement with
supporting rnember 20. The supporting member 20 can
also be provi~led with a surface 22 having a high
coefficient of friction. The biaising force needs to
be just enough to create a frictional re-taining force
between surfaces 22 and 54 which will prevent the
assembly from falling when the seat is not in use.
It will be seen from Eigure 3 that when a user
sits on seat 30, a vertical force W is applied to the
assembly. Force W causes cam 50 to act as a wedge
thus increasing the retaining capabilities of the
assembly. ~urthermore, lower roller 70 acts as a
pivot joint such that a reaction force having a
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horizontal component R is applied to support member
20 by cam 50 thus considerably increasing the
frictional retaining force generated between surfaces
22 and 5~. Thus, the assembly is held in holding
engagement with support member 20.
When it is required to change the height of the
seat 30, the user gets off the seat and turns said
cam 50 in its position where surface 22 is no longer
in con-tact with surface 54 and slides the assembly to
the desired position on support member 20~ A pair of
wheels 55 prevents that surfaces 22 and 54 from
coming in contact while the user changes the height
of seat 30. When this position is reached, the user
releases the handle, which causes the cam to rotate
so tha-t surfaces 22 and 54 are again in frictional
engagement with each other and re-tain the assembly a-t
the desired height.
It will be understood that the invention is
described by way of an examp:Le on:Ly and that
dl~ferent embodiments can be made w:ithout ~eparting
from the .spirit of thf3 i.nvention.
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