[0001] The present invention is a seat having, thefacility of assisting the user to rise
when he wishes to leaveit.
[0002] It is a recurring problem for persons of limited agility that they have difficulty
raising themselves from a comfortable sitting position when wishing to leave the seat.
The problemis aggravated when the seat is a relatively low one. It is undesirable
and restricting for a user to have to seek assistance in rising from a seat and therefore
it has previously been suggested that a seat may incorporate some mechanical means
of such assistance. However no wholly satisfactory seat of this type is available.
[0003] One disadvantage of previously available such seats is that they do not adequately
cater for a range of users of different weights and physical strengths. Another is
that some such prior seats are not able to withstand the repeated wear entailed in
regular daily use.
[0004] It is therefore an object of the present invention to provide a seat which adapts
to give adequate assistance in rising to a wide range of different users and which
may be made in a simple but robust construction which can survive regular repeated
use.
[0005] According to the present invention, a seat to give assistance in rising to the user
is hinged to the supporting frame at or adjacent to one edge of the seat and is urged
by at least one coil spring to lift relative to the frame by pivotting about the hinge,adjiustmet
means being provided to vary the tension in the spring by tightening or slackening
the coil.
[0006] Apart from the assisted-rising feature, the seat may in all other respects resemble
a conventional chair. If desired, the feature may be incorporated in a settee, with
one or more of the seats thereof being modified according to the invention, such seat
or seats being individually adjustable as described.
[0007] At least one coil spring is provided to urge the seat to lift about the hinge. In
a preferred form of the present invention, two such springs are provided. The spring
or springs may be mounted upon the seat itself but is/are preferably carried by the
supporting frame. Unless the spring is incorporated in the hinge itself (and for ease
of maintenance it is preferred that the spring or springs be separate from the hinge),
the point of action of the spring upon the seat will vary as the seat rises. For this
reason, the end of the spring which abuts the seat preferably carries a roller.
[0008] To allow the seat to adapt to the differing needs of different users, means are provided
to vary the. tension in the spring by tightening or slackening the coil. Thus a threaded
mechanism may be provided to enable continuous varying of the position of the end
of the coil remote from the seat itself.
[0009] A preferred form of the present invention comprises a seat hinged at or adjacent
to one edge thereof, two coil springs together carrying a roller at one of their ends,
the roller being disposed to bear upon the underside of the seat to urge it to pivot
upwards about the hinge, a rod or bar carried together by the springs at their other
ends, and adjustment means to move the rod or bar to increase or reduce the tension
in the coil sprinsgs.
[0010] In a particularly preferred form of the invention, a locking means is provided to
retain the seat in its down position. The locking means preferably is designed to
engage automatically when the seat approaches that position. The locking means may
be remotely operated so that it can be released manually from a point which is accessible
to the user when seated. Conveniently a manual release control may be provided for
the user, linked to the locking means by a flexible link such as a Bowden cable.
[0011] Other features of the present invention, and possible variations thereof, will become
apparent from the following description with reference to the accompanying drawings,
in which:
[0012]
Fig. 1 is a perspective view from the rear of the operating mechanism of one form
of seat according to the present invention;
FiF. 2 is a plan view of the seat of Fig. 1 with the seat portion itself removed; and
Fig. 3 is a vertical sectional view from the side of the seat illustrated in Figs.
1 and 2.
[0013] Referring to the drawings, the seat consists essentially of a box frame composed
of sides 4 and 5, back 6 and front 7, together with a seat portion 8, which forms
a "lid" to the box frame. The seat portion 8 is hinged to the frame front 7 by means
of hinges 9.
[0014] Extending between the sides 4 and 5, close to the front 7 of the frame is a cross-bar
10, about which a pair of coil springs 11 and 12 are mounted. At their upper ends,
the coil springs 11 and 12 carry a nylon roller 13, which bears upon a rigid plate
14, for example of "Formica" (Registered Trade Mark), secured to the underside of
the seat portion 8. Thus normal pressure of the springs urges the seat portion to
pivot upward and forwards on the hinges 9. When the user of the seat wishes to rise
from his sitting position, his lifting action is assisted by the upward pressure of
the seat portion under the influence of the springs 11 and 12.
[0015] It will be understood that different users of the seat will differ in weight and
also in the degree of assistance required. Adjustment of the seat to accommodate these
different needs is afforded as follows.
[0016] The lower ends of the springs 11 and 12 carry between them a tension bar 15, to which
they are secured. Extending between the rear frame member 6 and the bar 15 is a tension-
adjusting rod 16, which is threadedly engaged at one end with the bar 15 and carries
a knurled knob 17 at its other end. Thus, when the knob 17 is turned in a clockwise
direction, the threaded rod 16 is screwed further into the bar 15 and pulls it towards
the rear frame member 6, thereby increasing the tension in the coil springs 11 and
12 and enhancing the upward pressure on the seat portion 8. In this way, the person
rising from the seat is given increased assistance.
[0017] An optional, but highly advantageous, further feature of the illustrated form of
the invention is a locking means which operates to retain the seat closed. The locking
means takes the form of a sprung latch 18 (Fig. 3) mounted on a cross-member 19 of
the seat frame and arranged to engage a socket 20 on the underside of the seat portion
8. The seat would normally be held down by the weight of the user upon it but, in
order to permit setting of the springs 11, 12 to afford strong assistance to the user
in rising, while at the same time leaving him comfortable when seated, the locking
means retains the seat securely closed until the assistance in rising is reauired.
Sprintg operation of the latch 18 ensures that the seat locks automatically when it
is lowered, as by the user sitting upon it.
[0018] The latch 18 may be withdrawn from engagement with the socket 20 by means of a Bowden
cable 21, operated by a release lever 22 mounted on the underside of the arm (not
shown) of the seat, in a position readily accessible to the seated user. Thus when
the user wishes to rise, he merely operates the release lever 22 and thereby disengages
the latch 19 to gain the help in rising afforded by the springs 11 and 12.
[0019] As will be seen, the seat according to the present invention may be made in a simple
but robust form and is adapted to adjust to the needs of different users. In laboratory
tests, we have found that a seat in the form illustrated in the accompanying drawings
gave adequate assistance to users weighing from 7 stone to 15 stone and that the seat
mechanism survived 100,000 cycles of lifting and loweing without failure.
1. A user-assisting seat comprising a supporting frame, a seat hiniged to said frame
at or adjacent to one edge of said seat, at least one coil spring disposed to operate
between said frame and said seat so as to urge said seat to lift relative to said
frame by pivottining about the hinge, and adjustment means to vary the tension in
said spring by tightening or slackening the coil.
2. A user-assisting seat as claimed in claim 1, comprising two said coil springs.
3. A user-assisting seat as claimed in claim 1 or claim 2, wherein said at least one
coil spring is carried by the supporting frame and carries a roller at the end of
said spring which abuts said seat.
4. A user-assisting seat as claimed in any of the preceding claims, wherein said adjustment
means is a threaded mechanism to enable continuous varying of the position of that
end of the coil which is remote from the seat itself.
5. A user-assisting seat as claimed in any of the preceding claims, having two said
coil springs which together carry a roller at one end thereof, the roller being disposed
to bear upon the underside of said seat, a rod or bar carried together by said springs
at their other ends, and adjustment means to move the rod or bar to increase the tension
in said coil springs.
6. A user-assisting seat as claimed in claim 5, wherein said adjustment means is manually
operable.
7. A user-assisting seat as claimed in any of the preceding claims, having locking
means to retain the seat in its down position, said locking means being designed to
engage automatically when the seat approaches said down position and being manually
releasable from a point accessible to the user when seated.
8. A user-assisting seat as claimed in claim 7, wherein said locking means is linked
to a manual release control by a Bowden cable.