EP0663198A2

EP0663198A2 - Seating support

Info

Publication number: EP0663198A2
Application number: EP95200105A
Authority: EP
Inventors: Albert Haan; Willem Gijsbert Leonard De Jong
Original assignee: IDN Concepts BV
Current assignee: IDN Concepts BV
Priority date: 1994-01-17
Filing date: 1995-01-17
Publication date: 1995-07-19
Also published as: EP0663198A3; NL9400074A

Abstract

Seating support for individuals, comprising a substantially flat base member and a substantially flat seating support member, the seating support member comprising at least two seating support portions, of which the first seating support portion is hingedly connected to the base member and to the second seating support portion, the seating support further comprising adjustable tensioning means, such as torsion leaf spring packets, for biassing the seating support member to a receiving position, in which the second seating support portion is situated at a distance from the base member.

Description

The invention relates to a seating support, intended in particular for disabled persons.
Rising from a sitting position is an exercise which requires quite some effort, while going from a standing position to a sitting position is an exercise which requires much of the balance-maintaining ability of the person concerned. Healthy persons perform these movements many times a day, without encountering the slightest difficulty. A slight affection in the person concerned, however, can already cause problems in rising and sitting down, even while walking and standing are in themselves still reasonably possible. For people having a slight physical dysfunction, this can mean that they encounter restrictions in their ability to function independently. In this respect, one could think in particular of persons with muscular diseases and/or (slight) rheumatism.
In the past, much thought has been given to aids to facilitate sitting down and rising for the above-mentioned persons. A first example hereof is the chair of Dutch patent application 68.12336, of which the seat is connected on the front edge to the chair frame by means of a hinged joint, the hinged joint containing a torsion leaf spring packet, arranged such, that the leaf springs are tensioned when the seat is folded down to a horizontal position. The torsion leaf spring packet is adjusted to the user in such a way, that a spring force is supplied in the folded position of the seat, which spring force is at least approximately equal to the weight of the user of the chair. A drawback of this chair is that the user must be able, upon rising and sitting down, to control a movement of his trunk over what is still a fairly considerable horizontal distance.
An improvement in this respect is formed by another chair, known from WO 92/14432, of which the seat, connected with the front edge to the chair frame by means of a hinged joint, consists of two parts, connected to each other by means of a second hinged joint. The rear seat part is formed integrally with the back and the arm rests. Both seat parts, together with front portions of two fixed side beams of the chair frame and a system of rods hingedly connected thereto, form a four-bar mechanism, said system of rods being connected to the chair frame by means of an hydraulic telescopic rod or a rod provided with a compression spring. In the latter case, the four-bar mechanism is biassed to a receiving position of the seat, in which the front seat part and the rear seat part are orientated substantially vertically and horizontally, respectively.
A chair similar to this is known from British patent 1,406,420, in which the front part and the rear part of the seat form part of a four-bar mechanism, incorporated into the chair, and are tensioned to a receiving position by means of tension springs.
A drawback of both known chairs is that these special seating provisions are totally restricted to an individual chair and so can only be of use to the user in one location and are rather complex and/or bulky.
It is a main object of the invention to provide a seating support, intended in particular for disabled persons, which is easily transferable, can be placed or mounted on many chairs, does not adversely affect sitting comfort and which manages to effectively and safely support the movements made during rising and sitting down.
For this purpose, the invention provides a seating support for individuals, comprising a substantially flat base member and a substantially flat seating support member, the seating support member comprising at least two seating support portions, of which the first seating support portion is hingedly around a first axis connected to the base member by means of first connecting means, and is hingedly around a second axis, running parallel to the first axis, connected to the second seating support portion by means of second connecting means, the seating support further comprising tensioning means, for biassing the seating support member to a receiving position, in which the second seating support portion is situated at a distance from the base member. The base member is preferably plate-shaped, and the tensioning means are, on the one side, fastened to the seating support portion and, on the other side, fastened to the base member.
Notwithstanding it flat shape, the seating support according to the invention has the advantage of the two-part seat, as a consequence of which the distance, both in vertical and horizontal direction, over which the user has to substantially control the movement of his trunk, is greatly reduced.
The seating support is preferably provided with means for manually transferring said seating support, such as for instance a simple grip.
The seating support according to the invention forms a flat unit, which can be transferred by the user without great difficulty, for instance in a suitable case, during his transfer from one chair to another. The flat shape of the seating support according to the invention prevents that, if the seating support is placed on a chair, this would raise the sitting surface to such an extent that the sitting comfort would deteriorate.
The seating support according to the invention can also be suitable to be (temporarily) placed on or built into a movable or immovable piece of furniture, such as a common chair, desk chair, work chair, wheel chair or a stepping chair, wherein suitable means would of course be present to keep the base member of the seating support securely in place on an existing seat member or, instead of this, on the chair frame. When it is built in, the seating support stays outside the remaining parts of said piece of furniture due to its flat construction, thus keeping the production costs low and rendering replacement of the seating support easy and inexpensive.
In order to simply transfer the seating support according to the invention, it will suffice to apply for instance a sturdy clamp on the free (rear) ends of the seat member and the base member. However, the seating support according to the invention preferably comprises operable means for activating and deactivating the tensioning means. The tensioning means can herein be deactivated in the receiving position, after which the seating support member can simply be folded down and the seating support can be taken away for transfer. Reactivating the tensioning means can then also take place in the receiving position, in which the space available between the base member and the seating support member for movement of the hand of the user will unavoidably be largest. Deactivation can also be pleasant in fixedly mounted seating supports, in order to also render them usable for other persons.
The tensioning means are preferably arranged in at least one hinge point or junction. By concentrating the tensioning means in the hinge points or junctions, the amount of space occupied is minimized, to further the flat shape of the seating support according to the invention. The tensioning means can be provided as torsion spring means, which are preferably formed by composite springs, especially packets of torsion spring blades. An advantage of the use of packets of torsion spring blades according to the invention is that the spring force thereof can be adjusted fairly simply, namely by increasing or reducing the number of torsion spring blades while supplementing the packet by a relatively lighter filler, such as POM, or, which is preferred, by changing the clamping locations of the packet of torsion spring blades, as a consequence of which the active length thereof is changed.
It is remarked that from US patent 5,116,100 a portable seating support is known, having a base member and a seating support member, which are both formed by a roundgoing tube, stretched with cloth, and which are connected to each other by means of torsion springs. The seating support member hereof is of one piece, so that the base member, in order to support the initial phase of the sitting action and the final phase of the rising action, is provided with raised braces placed thereon, on which the user can find support with his hands.
In a further development of the seating support according to the invention, the second seating support portion is movably connected to the base member via third connecting means, which third connecting means are on the one side pivotably connected to the two-part seating support portion and on the other side pivotably connected to the base member.
The third connecting means, being preferably bar-shaped, complete a four-bar mechanism, formed by a part of the base member, the third connecting means, the second seating support portion and the first seating support portion. The tensioning means can herein be provided on at least one of the ends of the third connecting means, preferably on both ends. Providing the tensioning means on two or more different locations is advantageous from the point of view of keeping the seating support flat and, possibly, from the point of view of the adjustability of the spring force of the tensioning means. It is advantageous to herein let the working range of the different tensioning means be partially non-overlapping, so that the changes in increase and decrease of the spring force of the tensioning means as a whole can be geared to the demands which must be made of it on account of considerations regarding balance and comfort, during the movements from the receiving position to the operating position and vice versa.
The joint length of the two seating support portions is preferably approximately equal to the joint length of the third connecting means and the length of the portion of the base member extending between the third connecting means and the first connecting means, the length of the second seating support portion being greater than the length of the said base portion. Thus, it is achieved that in the receiving position the second seating support portion will take up an upwardly inclined position in rearward direction. The distance over which the user will himself have to control the movement of his trunk is hereby further reduced, while the user can also feel more secure during the action of sitting down. Generally, the posture of the user during the final phase of rising and the initial phase of sitting down is hereby improved.
As an elaboration of the possibility mentioned above of activating and deactivating the tensioning means, the third connecting means can be transferable between a position, in which the tensioning means are active, and a position, in which the tensioning means are not active, but in which the third connecting means continue to exercise their connecting function.
In order to increase seating comfort and to prevent that both seating support portions in the extreme operating position, that is to say the horizontal position of the seating support member, can become locked, by the hinge connection between both seating support portions moving through the 180°, the tensioning means are arranged to force both seating support portions to a mutual position, in which their bottom surfaces together define an angle which is smaller than 180°. This also prevents parts of the clothes of the user from becoming stuck between both seating support portions. Furthermore, a forward displacement of the user's trunk is herein also checked, while the pressure on the thighs is reduced.
It is especially advantageous if the seating support is provided with means for locking the tensioning means in several operating positions, in which the second seating support portion is situated at a distance from the base member. This embodiment is especially suitable for use in or to be built into the previously mentioned stepping chairs, because the user can then take up a position, in which the thighs can take up a more inclined position, which is advantageous for the extent to which and the ease with which the user can develop push-off forces. The user of the stepping chair or wheel chair can hereby moreover bring his trunk and thereby his upper body to different levels and keep it there, which offers a great deal of ease in performing acts at sinks, desks or kitchen-cupboards. The two-part design of the seating support member herein provides a guarantee against the user slipping off the seating support member.
The invention will now be elucidated by means of the embodiment represented in the accompanying drawing. The following is shown in:

figure 1: a perspective view on the embodiment of the seating support according to the invention, seen obliquely from the rear;
figure 2: a perspective view on the seating support of figure 1, but now under a more horizontal direction;
figure 3: a side view of the seating support of figures 1 and 2;
figure 4: a side view of the seating support of figures 1 and 2, but now in a folded position;
figure 5: a rear view of the seating support of figures 1 and 2;
figures 6A and 6B: examples of a seating support according to the invention, incorporated in a so-called stepping chair; and
figure 7: a schematic representation of the manner in which the seating support can be provided with adjustable tensioning means.

The seating support 1 of figure 1 and 2 comprises a base plate 2 having a grip 30 and a seating support member 3, comprising seating support portions 3a and 3b. The base member 2 and the seating support member 3 can be made of any suitable material, such as for instance wood, steel or a synthetic material. The seating support portions 3a and 3b are preferably provided with a cushion-like covering 4a and 4b, respectively, as is shown in figures 3, 4 and 5.
The base member 2 is connected to the seating support portion 3a by means of hinges 22 and 23, the hinge axis running parallel to the front edge of the base member 2. Hinge leaves of the hinges 22 and 23 are mounted on metal or synthetic blocks or box profile members 26 mounted on the base member 2, in order to leave (restricted) room, in the folded position, between the seating support portion 3a and the base member 2.
The seating support portion 3a is hingedly connected to the seating support portion 3b by means of hinges 24 and 25 (see figures 2, 3 and 5), the hinge axis running parallel to the hinge axis of the hinges 22 and 23.
Angle sections 5a and 5b are fastened to the bottom side of the seating support portion 3b, on which angle sections in their turn are fastened end clamps 20 21 for the ends of the torsion leaf spring packet 9. In a similar manner, the base member 1 is provided on both side edges with angle sections 7a and 7b fastened thereon, in which end clamps 18 and 19 for the ends of the torsion leaf spring packet 8 are fastened.
Near the middle of the torsion leaf spring packet 8 are provided, at some distance from each other, two annular guides 10 and 12, fastened onto the base member 2 by means of base plates 31 and 33. Also provided on the bottom side of the seating support portion 3b are a pair of guide rings 11 and 13, which are situated at a distance from each other which is equal to that of the mutual distance between the rings 10 and 12, and fastened onto the seating support portion 3b by means of base plates 32 and 34. As can be clearly seen in figures 1, 2 and 5, a bar or link bar 6 extends between the central areas of the torsion leaf spring packets 8 and 9, which engages with its upper end 6a around the leaf spring packet 9 and grasps with its lower end 6b around the leaf spring packet 8. The bar 6 and thereby the ends 6a and 6b thereof can be slid back and forth in the plane in which the torsion spring packets 8 and 9 are located. This is shown more clearly in figure 5, from which is becomes clear that compression springs 14 and 15 are placed between the guide rings 12 and 13 and the ends 6a and 6b, which compression springs force the ends 6a and 6b of the bar 6 in a direction A, as seen in the drawing towards the left. The springs 14 and 15 surround sockets 16 and 17, respectively, which are borne rotatably with their ends in the guide rings 10, 12 and 11, 13, respectively. On their left-hand side, as seen in figure 5, the sockets 16 and 17 are provided with a part having an enlarged circumference. The ends 6a and 6b are also sleeve-shaped, the dimensions thereof being chosen such in relation to the dimensions of the part of the sockets 16 and 17 having an enlarged circumference, that free mutual pivoting is not possible. The ends 6a and 6b, however, are therein freely rotatable around the remaining part of the sockets 16 and 17, which themselves closely fit around the leaf spring packets 8 and 9, for joint rotation therewith.
In the position shown in figure 3, both leaf spring packets 8 and 9 are unloaded. In this position, the four-bar mechanism can clearly be seen, formed by the portion of the base member 2 between the hinge axis of the hinges 22 and 23 and the centre line of the leaf spring packet 8, the link bar 6, the seating support portion 3b and the seating support portion 3a. The lengths of these portions a, b, c and d are herein chosen such, that a + b is approximately equal to c + d, so that a flat folded position, shown in figure 4, can be realized. Herein, a is smaller than c and b is larger than d, in order to ensure that the rear end of the seating support portion 3b in the receiving position shown in figure 3 is situated higher than the front edge thereof. The seating support portion 3a is therein substantially vertical.
When the user places his trunk on the upper surface of the seating support portion 3b, the seating support portions 3a and the link bar 6 will be swung in the direction B. During this movement, the upper end 6a of the link bar 6 exercises a torsional moment C on the part of the socket 17 having an enlarged circumference, which socket 17, due to its closely fitting arrangement around the leaf spring packet 9, exercises a similar twisting moment on the leaf spring packet 9. The ends of the leaf spring packet 9 are herein retained against twisting in the end clamps 20 and 21. The same thing takes place at the lower bar end 6b, where the engagement of the lower end 6b on the part of the socket 16 having an enlarged circumference and the rotation-fixed fitting of socket 16 around the leaf spring packet 8 ensures twisting of the leaf spring packet 8 by means of moment D, wherein the leaf spring packet 8 is retained with the ends against twisting by the end clamps 18 and 19. If desired, it can be decided to make the engagement of the ends 6a and 6b on the enlarged circumferences of the sockets 16 and 17 such, that the one bar end will start to exercise a torsional moment some time later than the other bar end.
The pivoting in the direction B continues until the folded operation position of figure 4 has been realized. In this position, the user is sitting with his or her ischii on the seating support portion 3b and with the thighs on the seating suport portion 3a. Because the torsion leaf spring packet 8 is tensioned, a moment in the direction E is exercised on the seating support portion 3b, as a consequence of which the seating support portions 3a and 3b tend towards a mutual position, in which they are at an angle relative to each other which is smaller than 180°, as represented in figure 4. This prevent articles of clothing from becoming stuck or, worse, fingers from becoming wedged in the gap between the seating support portions 3a and 3b. This furthermore ensures that upon rising, the seating support portion 3 can swing to the mutual position represented in figure 3 without any difficulty. As previously mentioned, this position, shown in figure 4, moreover increases sitting comfort for the user.
When it is necessary to transfer the seating support 1, the user grasps the bar 6 in the position of the seating support represented in figure 3 and moves it in the direction A towards the left (as seen in figure 5), whereby the ends 6a and 6b will compress the springs 14 and 15. When the ends 6a and 6b have been slid off the portions of the sockets 16 and 17 having an enlarged circumference, the leaf spring packets 8 and 9 will no longer be twisted when the bar 6 is pivoted in the direction B. The seating support members 3a and 3b can then be let down under the influence of the gravitational force to the position represented in figure 4, in which the seating support portions 3a and 3b will however be able to assume a mutual angle of 180°. The rear edge of the seating support portion 3b and the rear edge of the base member 2 can possibly be kept together by means of a temporary clamp (not shown), which will, however, not need to exercise any great clamping force.
When the user goes to another room, he or she can easily transport the seating support 1 by means of the grip 30, wherein it is advantageous that the seating support according to the invention is relatively flat en can easily be (far) thinner than for instance 10 cm. Consequently, the seating support can easily be put away in for instance a travelling case. The moving parts are located in the space between the seating support portions and the base member and do not require any external provisions in order to function.
When the user has arrived at a location where he or she wishes to once again use the seating support 1, he or she lifts up the seating support portion 3b to the position shown in figure 3, upon which the compression springs 14 and 15 will ensure that the ends 6a and 6b are forced in the direction A, towards the left (figure 5) to a position in which they engage around the portions of the sockets 16 and 17 having an enlarged circumference. The seating support is then made ready, in an almost automatic manner, for re-use.
The force with which the seating support portions 3a and 3b are forced into the position represented in figure 3 can be altered, by for instance changing the number of leaf springs in packet 8 and/or packet 9. It is also possible, as is not shown, to make the location of the end clamps 18, 19 and 20, 21 variable, for instance by fastening them on rail parts which reach in the direction A and which are fastened on the portions 3b and 2, wherein they can be fastened at any desired location on the rail.
During rising, the spring force will decrease, possibly to an unequal extent for both spring packets so as not to transfer the user too quickly at the end of that movement. It is possible to include angle-limiters in the hinges 22-25, in order to prevent the seating support portion 3b from moving too far.
Figures 6A and 6B show the seating support according to the invention on a so-called stepping chair. Figure 6A shows the built-in, flat seating support in a position corresponding to that of figure 3. The seating support 101 comprises a base plate 102, an articulated seating support member, formed by seating support portions 103a and 103b and a link bar 106. The seating support 101 substantially corresponds to the seating support shown in the preceding figures.
The seating support 101 is secured on the substantially horizontally running frame parts 141 of the stepping chair by means of bolt connections 140. What is special, now, is that the seating support portion 103a is provided on the side edge with a pin 143. This pin 143 fits into the grooves 146 which have been provided in locking plate 142, which is rotatably mounted on the side edge of the base plate 102 by means of pin 145. The locking plate 142 is provided on the other end with a knob-shaped grip 144.
When a person is about to use the stepping chair 100, he or she will sit down on the seating support 101 of the stepping chair 100 in the position represented in figure 6A. Under the weight of the person, the seating support portions 103a and 103b will then swing in the direction F, just as this will happen in the embodiments of figures 1-5. When the seating support portions 103a and 103b have been swung so far, that an optimum position for that person has been assumed on the stepping chair, in which position the so-called stepping action can take place without difficulty, the user seizes the knob 144 and swings the locking plate 142 in the direction G, until the pin 143 falls into one of the holes 146. Hereby it is prevented that as a consequence of the user's weight, the seating support portions 103a and 103b will swing further to a position in which they almost abut the base plate 102. Other types of locking means are of course also possible, as well as extra means to prevent the inadvertent release of the pin 143 from the holes 146.
It is also possible that the user operates the locking plate in order to (temporary) change the height of the seating support portion 103b during use, in order to for instance reach a kitchen-cupboard.
Figure 7 shows in what manner the tensioning force of a torsion leaf spring packet provided on the base plate of the seating support according to the invention can be changed. The leaf spring packet 208 is herein not kept clamped on the edges against rotation, in contrast to what is the case in the embodiment of the seating support according to the invention of figures 1-5. Instead, two rigid sleeves 218 and 219 are provided, which closely surround the circumference of the leaf spring packet. The sleeves 218 and 219 are secured to adjusting sleeves 250 and 251, which are slidable, in the directions E, over a location-fixed bar 254. The location of the adjusting sleeves 250 and 251 on the bar 254 can be secured by means of screws 252 and 253.
When the force required for transferal of the seating support member (not shown) relative to the base member 202 must be increased, the sleeves 218 and 219 are brought closer together, as a consequence of which the active length of the torsion leaf spring packet 208 is reduced and thereby the force required for rotation is increased.
It will be understood that the seating support according to the invention is easy to handle and to transport and that it will therefore realise an increase in the action radius and an improvement in functioning for the user.

Claims

Seating support for individuals, comprising a substantially flat base member and a substantially flat seating support member, the seating support member comprising at least two seating support portions, of which the first seating support portion is hingedly around a first axis connected to the base member by means of first connecting means, and is hingedly around a second axis, running parallel to the first axis, connected to the second seating support portion by means of second connecting means, the seating support further comprising tensioning means, for biassing the seating support member to a receiving position, in which the second seating support portion is situated at a distance from the base member.
Seating support according to claim 1, the tensioning means being, on the one hand, fastened to the seating support portion and, on the other hand, fastened to the base member.
Seating support according to claim 1 or 2, the base member being plate-shaped.
Seating support according to claim 1, 2 or 3, the seating support being provided with means for manually transferring and taking along said seating support.
Seating support according to any one of the preceding claims, comprising operable means for activating and deactivating the tensioning means.
Seating support according to any one of the preceding claims, the second seating support portion being movably connected to the base member via third connecting means, being preferably bar-shaped, which third connecting means are on the one side pivotably connected to the two-part seating support member and on the other side pivotably connected to the base member.
Seating support according to claim 5 or 6, the tensioning means being provided on at least one of the ends of the third connecting means, preferably on both ends thereof.
Seating support according to claim 5, 6 or 7, the joint length of the two seating support portions being approximately equal to the joint length of the third connecting means and the length of the portion of the base member extending between the third connecting means and the first connecting means, the length of the second seating support portion being greater than the length of the said base member portion.
Seating support according to any one of the claims 6, 7 or 8, the third connecting means being transferable between a position, in which the tensioning means are active and a position, in which the tensioning means are not active, but in which the third connecting means continue to exercise their connecting function.
Seating support according to any one of the preceding claims, the tensioning means being provided in at least one hinge point or junction.
Seating support according to any one of the preceding claims, the tensioning means comprising torsion spring means, which are preferably formed by composite springs, especially packets of torsion spring blades and which are preferably adjustable in spring force, preferably by adjusting the active length of the packet.
Seating support according to any one of the preceding claims, the tensioning means being substantially unloaded when the first seating support portion is substantially perpendicular to the base member.
Seating support according to claim 12, the tensioning means comprising a plurality of spring means, of which the working area is in part non-overlapping.
Seating support according to any one of the preceding claims, comprising means for locking the tensioning means in several operating positions, in which the second seating support portion is situated at a distance from the base member.
Seating support according to any one of the preceding claims, the tensioning means forcing both seating support portions in the operating position to a mutual position, in which their bottom surfaces together define an angle which is smaller than 180°.