GB1578395A - Lifting seats - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO LIFTING SEATS (71) We, RENRAY PRODUCTS (U.K.) LIMITED, of King Street, Middlewich, Cheshire, CW10 9LG, previously of 75 Woodvale Road, Belfast, BT13 3BP, Northern Ireland, a Northern Ireland Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to lifting seats for use by persons who are physicallyhandicapped by reason of, for example, age, infirmity or recovering from operations, and is to assist them by mitigating body movement exertions involved in rising from and sitting down on a seat.Such lifting seats may be either incorporated into specially designed seats or chairs, or can be simply located on top of an existing seat, chair or other suitable location. Lifting seats have been provided heretofore and each generally comprised two similar members, namely a bottom member to one side of which a top member is hingedly connected, the members being urged apart by biasing means and a stop being provided to limit the amount of opening movement of the top member away from the bottom member. Hereinafter in the specification and claims, a lifting seat abovedescribed will be referred to as "a lifting seat of the type aforesaid".

A disadvantage exists in lifting seats hitherto available in that they are not interchangeable between persons of different weights since each lifting seat has biasing means commensurate with a restricted range of loadings so that it can be used to assist body movement of people differing only slightly in weight. The biasing means are located in the seats during manufacture and prior to the upholstering of the seats. There is no way, except by removing the upholstery, that the loadings can be changed. This causes particular problems in establishments, such as hospitals or clinics, where different people have use of these seats at frequent intervals.

It is an object of the present invention to obviate or mitigate the above disadvantage.

According to the present invention, there is provided a lifting seat of the type aforesaid in which the biasing means is formed from a series of separate biasing units mounted to act, when in use, on both the bottom and top members at or adjacent to the hinge axis, each unit having a particular loading and the loading of the biasing means being determined by the cumulative total of the individual loadings, each unit including means, accessible externally of the seat, to render the biasing unit inoperative and therefore to remove its loading from the cumulative total loading.

Preferably, each biasing unit is a torsion spring having extended straight ends to react with the bottom and top members respectively.

Preferably also, said means comprises a block secured to the end of the spring reacting with the top member, and having a tapped bore in the end face opposed to the bottom member to enable a bolt from the outside face of the bottom member to pass through a hole in the bottom member and screw-threadedly engage in said tapped bore when the members are together against the influence of said biasing means, thereby excluding said spring end from involvement in movement of said top and bottom members relative to one another.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is a perspective view of a lifting seat according to the present invention showing the upholstery of the bottom member turned over on itself to reveal the biasing means; and Figure 2 is a perspective view of the seat to a smaller scale and from underneath and showing a locking mechanism.

A lifting seat of the type aforesaid is for use with its bottom member 10 located in a horizontal plane. The bottom member 10 is formed from a U-frame 11 of tubular piping, and has a cross-piece 12 of tubular piping between the limbs lIA thereof adjacent to their outer ends. An angle bar 13, parallel to the crosspiece 12, is provided with the one arm 13A nearer the cross-piece horizontal, and the other arm upstanding. The outer ends of the limbs 1 lA are sloped downwardly and provide a stop 14 against which the top member 15 rests to prevent further movement apart of the members 10 and 15 under the influence of the biasing means.

The top member 15 has a rectangular frame of similar areal dimensions to the bottom frame 11, and has a plate 16 secured across one end, i.e. that end hingedly connected to the bottom member 10. Three spaced metal leaves 17 are mounted on said plate 16 with the knuckles thereof around said cross-piece 12 which forms the hinge pin of the hinge.

The biasing means comprises nine biasing units each formed of a torsion spring 18 arranged around the cross-piece 12 and with extended straight ends to react with the top of the horizontal arm 13A of the angle bar 13, and the other to react against the plate 16, the springs 18 being located between the centre and each of the outer two brackets 17.

Means to render a biasing unit inoperative are provided at the outer end of each end of the springs 18 reacting with the plate 16. The means comprises a cylindrical block 19 having adjacent to one end a diametrical bore 20 and in the opposite end an axial tapped hole 21. The outer end of the straight end of the spring reacting with the plate 16 is located in said diametrical bore 20 and secured therein, with the end of the block 19 having the tapped hole 21 opposed to the horizontal limb 13A which is provided with nine apertures 22 positioned with one to correspond to each tapped hole 21. None holes 23 are located in the plate 16, one each to seat the end of the respective block 19, namely that part of the block 19 between the diametrical bore 20 and its nearer end.

The seat is upholstered enclosing the frames and biasing means.

The loading of the biasing means is determined by the total cumulative loading of each of the springs 18. The cumulative loading can be adjusted by excluding the end of one or more than one spring 18 from involvement in movement of said top and bottom members 10 and 15 relative to one another. To make this adjustment, the seat is inverted with the top member 15 or seating portion facing downwards and the bottom member 10 pushed down on top thereof and a bolt 24 (Figure 2) is inserted through the upholstery and through the appropriate aperture 22 in the bottom member 10 to screw-threadedly engage in the tapped holes 21 in the block of the or each spring 18 which is to be rendered inoperative. For example, the springs are numbered in left to right order from 1 to 9 and the loadings are such that the approximate weight of person to be lifted is given as follows:- Approximate weight to be lifted Spring No. (in stones weight) 1 2 2 4 3 6 4 7 5 9 6 10+ 7 12+ 8 14 9 16 If a person is particularly frail or if the support for the bottom member is soft, such as a settee, the next higher spring to the loading required is also used, for example, if the weight to be lifted is 9 stones, then the springs 1 to 6 are in use and springs 7, 8 and 9 are withdrawn. Each spring, when loaded gives a mean torque of five pounds weight feet.

The above-described lifting seat is advantageous in that it enables the seat to be readily adjusted to give a greater or lesser total cumulative loading for the weight of a particular person who is to use the seat.

Locking means as shown in Figure 2, is provided to lock the two members 10 and 15 together against the biasing, the locking means comprising a bolt 25 one end of which protrudes through the front face of the seat and has a knob handle 26 secured thereto, and the other end is axially offset to engage around the web 11B of the frame 11.

WHAT WE CLAIM IS: 1. A lifting seat of the type aforesaid in which the biasing means is formed from a series of separate biasing units mounted to act, when in use, on both the bottom and top members at or adjacent to the hinge axis, each unit having a particular loading and the loading of the biasing means being determined by the cumulative total of the individual loadings, each unit including means, accessible externally of the seat, to render the biasing unit inoperative and therefore to remove its loading from the cumulative total loading.

2. A lifting seat as claimed in Claim 1, wherein each biasing unit is a torsion spring having extended straight ends to react with the bottom and top members, respectively.

3. A lifting seat as claimed in Claim 1 or 2, wherein said means comprises a block secured to the end of the spring reacting with the top member, and having a tapped hole in the end face opposed to the bottom member to enable a bolt from the outside face of the bottom member to pass through a hole in the bottom member and screw-threadedly engage in said tapped hole when the members are together against the influence of said biasing means, thereby excluding said spring end from involvement in movement of said top and bottom members relative to one another.

4. A lifting seat as claimed in Claim 1, 2 or 3, wherein locking means are provided to lock the two members together against the biasing.

5. A lifting seat substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. springs 7, 8 and 9 are withdrawn. Each spring, when loaded gives a mean torque of five pounds weight feet. The above-described lifting seat is advantageous in that it enables the seat to be readily adjusted to give a greater or lesser total cumulative loading for the weight of a particular person who is to use the seat. Locking means as shown in Figure 2, is provided to lock the two members 10 and 15 together against the biasing, the locking means comprising a bolt 25 one end of which protrudes through the front face of the seat and has a knob handle 26 secured thereto, and the other end is axially offset to engage around the web 11B of the frame 11. WHAT WE CLAIM IS:

1. A lifting seat of the type aforesaid in which the biasing means is formed from a series of separate biasing units mounted to act, when in use, on both the bottom and top members at or adjacent to the hinge axis, each unit having a particular loading and the loading of the biasing means being determined by the cumulative total of the individual loadings, each unit including means, accessible externally of the seat, to render the biasing unit inoperative and therefore to remove its loading from the cumulative total loading.

2. A lifting seat as claimed in Claim 1, wherein each biasing unit is a torsion spring having extended straight ends to react with the bottom and top members, respectively.

3. A lifting seat as claimed in Claim 1 or 2, wherein said means comprises a block secured to the end of the spring reacting with the top member, and having a tapped hole in the end face opposed to the bottom member to enable a bolt from the outside face of the bottom member to pass through a hole in the bottom member and screw-threadedly engage in said tapped hole when the members are together against the influence of said biasing means, thereby excluding said spring end from involvement in movement of said top and bottom members relative to one another.

4. A lifting seat as claimed in Claim 1, 2 or 3, wherein locking means are provided to lock the two members together against the biasing.

5. A lifting seat substantially as hereinbefore described with reference to the accompanying drawings.