U.S. patent number 3,858,834 [Application Number 05/430,318] was granted by the patent office on 1975-01-07 for locking mechanism for pedestal seat.
This patent grant is currently assigned to Universal Oil Products Company. Invention is credited to Shawn H. Eimen.
United States Patent |
3,858,834 |
Eimen |
January 7, 1975 |
LOCKING MECHANISM FOR PEDESTAL SEAT
Abstract
Locking mechanism for a pedestal mounted seat is actuated by a
spring biased handle which is mounted on the seat and which moves
with the seat and carries an eccentric cam and guide member. In one
position of adjustment, an outer tube carried by the seat is free
to rotate about an inner tube carried by a floor mounted pedestal
until the seat is in its aligned forward position at which point
the guide member is moved into a slot in the inner tube. When the
seat is in its forward position with the guide member in the slot,
movement of the handle will rotate the eccentric cam into
progressively greater contact with portions of the outer surface of
the inner tube which are immediately adjacent the slot so as to
prevent any wobbling taking place between the two tubes.
Inventors: |
Eimen; Shawn H. (Cudahy,
WI) |
Assignee: |
Universal Oil Products Company
(Des Plaines, IL)
|
Family
ID: |
23707009 |
Appl.
No.: |
05/430,318 |
Filed: |
January 2, 1974 |
Current U.S.
Class: |
248/418;
297/344.22; 403/84 |
Current CPC
Class: |
B60N
2/143 (20130101); A47C 3/18 (20130101); Y10T
403/32262 (20150115) |
Current International
Class: |
A47C
3/18 (20060101); A47C 3/00 (20060101); B60N
2/04 (20060101); B60N 2/14 (20060101); A47c
003/00 () |
Field of
Search: |
;297/349
;248/418,425,415,406 ;403/109,323,330,322,84 ;105/345
;108/142,139 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McCall; James T.
Attorney, Agent or Firm: Hoatson, Jr.; James R. Clark; Barry
L. Page, II; William H.
Claims
I claim as my invention:
1. In a rotatable seat for a motor vehicle having an outer tubular
member attached to the seat frame and a telescoped inner tubular
member attached to a base, the improvement comprising bracket means
affixed to said outer tubular member, shaft means carried by said
bracket means, cam means and detent means carried by said shaft,
handle means on said shaft means for rotating said shaft, cam and
detent means, a first aperture means formed in said inner tube and
a second aperture means formed in said outer tube, said second
aperture means being larger than said first aperture means and
positioned relative to said first aperture means so that when the
seat is in its driving position the first aperture means is
positioned centrally of the second aperture means and aligned with
said detent means whereby rotation of said handle means will cause
said detent means to move into or out of said first aperture means
and will cause said cam means to move into or out of evertightening
engagement with portions of said inner tube located immediately
adjacent said first means so as to force portions of said inner and
outer tubes into binding contact with each other.
2. The device of claim 1 characterized in that said cam means and
detent means are integral.
3. The device of claim 2 characterized in that said cam means
includes a cam surface which is eccentric relative to said shaft
and said detent means projects radially outwardly from said cam
surface over the major portion of its extent.
4. The device of claim 1 characterized in that a spring is mounted
on said shaft and connected to said shaft and to said bracket means
for biasing said detent means towards said inner tube.
Description
BACKGROUND OF THE INVENTION
With the development of motor home and other multiuse vehicles a
need has arisen for seats which can be rotated from a forward
facing driving position to a position facing the interior of the
vehicle. In order that the seat will be firmly anchored to the
floor it is usually mounted on a pedestal comprising a pair of
telescoped tubes which can be locked against rotation.
SUMMARY
It is among the objects of this invention to provide a rotatable
vehicle seat support which can be locked in any position of
rotation and easily and quickly released and moved to another
position.
It is another object of this invention to provide a single lever
actuated mechanism which will automatically lock the seat against
rotation as it is rotated to its driving position and lock it
against vibration.
These and other objects are accomplished by the improved mechanism
of the present invention wherein a seat is provided with a tubular
member projecting downwardly from its bottom into telescopic
surrounding relation to a tubular member projecting upwardly from a
floor mounted pedestal. A pair of brackets extend outwardly from
the outer tube on opposite sides of an aperture. An elongated shaft
having a handle portion on one end is mounted in the brackets and
carries an eccentric cam member which is keyed to the shaft so that
rotation of the handle will move the cam within the aperture into
and out of engagement with a portion of the outer wall of the inner
tube. When the cam engages the inner tube it forces the inner and
outer tubes into tight engagement on the side thereof opposite the
aperture so as to eliminate any looseness between the tubes which
could cause rattles or vibrations during vehicle operation. A
semi-annular ring portion on the cam is adapted to be moved into
and out of a slot in the inner tube when the seat is aligned in its
forward driving position. The ring cooperates with the sides of the
slot to prevent rotary motion. A spring mounted on the shaft and in
engagement with one of the brackets biases the ring towards the
inner tube.
The operation of the mechanism can be briefly described as follows:
assuming the seat is in its locked forward facing position the
handle is turned to rotate the shaft which releases the cam from
engagement with the inner tube and retracts the semi-annular ring
from the slot. The handle can be released as soon as the seat is
rotated a small distance away from the slot and the seat can be
rotated to any position. The seat can be re-aligned in its forward
position without touching the handle by simply rotating it until
the spring biased semi-annular ring falls into the slot. Although
the seat is locked against rotation in this position it is
preferable to rotate the handle with some force to cause the
eccentric cam to bind against the inner tube. This binding action
prevents the tubes from rattling against each other or against the
semi-annular ring and permits the tubes to be made with rather
large manufacturing tolerances. It also overcomes the effects of
wear on the tubes during use since the cam surface can be made to
accommodate a large range of size variations between the two
tubes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially exploded, partially broken away perspective
view of the improved locking mechanism;
FIG. 2 is a side sectional view showing the locking cam when the
seat is not in its forward facing position; and
FIGS. 3 and 4 are side sectional views showing the locking cam in
its initial and final contact positions relative to the tubular
seat support members when the seat is in its forward facing
position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a rotatable seat indicated generally at 10
includes a seat cushion 12 carried by a seat frame 14. An outer
tubular member 16 welded to the seat frame 14 is telescoped over
inner tubular member 18 which is welded to pedestal base member 20.
A plurality of openings 22 formed in the base 20 may be used to
receive a number of screws (not shown) which fasten the base 20 to
the floor of a vehicle (not shown). Preferably, the fit between the
outer and inner tubes 16,18 is a little loose to permit easy
rotation of the seat 12 and to allow for manufacturing tolerances.
Because of the loose fit the various portions of the unit 10 tend
to rattle due to the vibrations of the vehicle (not shown) to which
it is attached. To overcome the rattle, a centering and locking
mechanism indicated generally at 23 has been provided.
The centering and locking mechanism 23 comprises a pair of brackets
24,26 which are welded to the outer tube 16. Circular openings 28
in the brackets function as bearings for a shaft 30 having a handle
portion 32 integrally formed therefrom. In order to bias the shaft
30 in the direction indicated by the arrow a spring 36 is placed
over the shaft and affixed at one end to a hole 38 in bracket 24
and affixed at its other end to an anchor pin 40 pressed into the
shaft 30. An eccentric cam member indicated generally at 44 is
affixed to the shaft 30 by a set screw 45. The eccentric cam member
44 has a gradually varying cam surface which includes a low cam
surface portion 46 and a high cam surface portion 48. Extending
outwardly from said cam surface between portions 46 and 48 is a
semi-annular ring portion 50 having a leading edge 51 which is
biased towards tubes 16,18 by spring 36. A slot 52 having a width
slightly greater than the width of ring portion 50 is formed in
inner tube 18. The slot 52 is positioned to receive ring portion 50
when the seat 12 is in its forward facing position so that the seat
may be locked against rotation when in its driving position. An
aperture 54 formed in the outer tube 16 is larger than the slot 52
so as to expose inner tube surfaces 56 on each side of slot 52 when
the seat in in its driving position.
When the handle 32 is moved against the spring 36 to the upper
dotted line position shown in FIG. 1 the cam 44 will be in the FIG.
2 position wherein the ring portion 50 is withdrawn from slot 52,
thus permitting the seat 12 to be rotated to any desired position.
Once the seat is rotated sufficiently far to prevent the ring
portion 50 from reengaging slot 52 the handle 32 may be released
and the edge 51 of ring portion 50 will merely ride on the surface
of inner tube 18. As the seat is rotated back to its forward facing
position the ring portion 50 will snap into slot 52 and prevent
further rotation. When the ring portion 50 snaps into the slot 52
the handle 32 will assume the position shown in solid lines in FIG.
1 and the cam 44 will assume the FIG. 3 position. By applying
manual pressure to force the handle 32 to the lower dotted line
position shown in FIG. 1 the cam 44 will be rotated to cause the
cam to press increasingly harder against the surfaces 56 of the
inner tube 18 and cause the rear surfaces (not shown) of the tubes
16, 18 to bind together. The pressure increases since the cam is
eccentric and surface 48 is further from the center of rotation of
the cam than is surface 46. This firm pressure provided by the cam
surface 48 prevents rattling taking place between the two tubes and
between the ring portion 50 and the side edges of slot 52.
* * * * *