EP4070773A1 - Seat assembly with dynamic seat pan - Google Patents

Abstract

The invention relates to a seat arrangement with a frame, which has two mutually parallel bars (10), and a seat surface arranged on the frame, which is attached to the frame in a displaceable and pivotable manner in the direction of the bars (10), and with a fastening unit which a seat of the seat arrangement is slidably and pivotably attached to at least one of the bars (10). The object of the invention is to propose a simple and reliable arrangement for the slidable and pivotable attachment of the seat shell of the seat arrangement. To solve this problem, each bar (10) and the fastening unit for the displaceable and pivotable fastening of the seat (7) to the frame (1) has guide elements which interact with one another and which comprise elongated holes (13) running in the longitudinal direction of the bars (10) and connecting bolts (14) projecting through the elongated holes.

Description

The invention relates to a seat arrangement with a frame, which has two mutually parallel spars, and a seat arranged on the frame, which is slidably and pivotably attached to the frame in the direction of the spars, and with a fastening unit, which slidably and pivotably attaches the seat attached to at least one of the spars. The invention relates in particular to a seat arrangement for people with physical disabilities, in particular wheelchairs or baby carriages.

The generic state of the art goes back to the European patent EP 0 911 008 B1 back to the applicant for a movable seat arrangement. The wheelchair described here and the seat arrangement described here is used in particular to accommodate patients who suffer from spastic cramps. In these patients, uncontrolled impulses are delivered to the muscles, which lead to spasmodic muscle tension, which generally causes the body to stretch. This means that the seated person unintentionally works their muscles in such a way that the hip joints and knee joints are compressed. In order to prevent the patient from falling out of the seat shell of the seat arrangement, he is usually fixed to the seat shell with fastening means, which include, for example, a lap belt or lap bracket. In conventional wheelchairs with a rigid seat or a locked, adjustable seat shell in which the patient is fixed, in the event of a spasm, the patient's muscular forces act against the rigid or locked seat shell, which keeps the patient's joints in the angled position and the patient in his or her position Seat position fixed. On the one hand, this means that the muscle tension cannot lead to a stretching of the body and the muscles and joints of the patients are subjected to severe mechanical stress.

Furthermore, the full muscle power is introduced into the fastening means and into the seat shell, so that here too there is considerable mechanical stress.

The one in the EP 0 911 008 B1 The arrangement described solves these problems by proposing that the seat and backrest are connected to one another in a freely pivotable manner, with a tensioning device being provided which generates a tensioning force that holds the seat and backrest to one another in the bent sitting position, and that the footrest can be freely pivoted on the Seat is articulated, wherein a clamping device is provided which generates a clamping force holding the footrest in the bent seat position to the seat. Specifically, a linear guide is attached to the frame of the wheelchair chassis below the seat. The seat surface is pivoted on the displaceable component of the linear guide. A variant of the seating arrangement from the EP 0 911 008 B1 goes out of DE 101 08 312 A1 out. Here, lateral profiles with grooves are arranged on the seat and backrest, to which fastening and connecting elements can be attached in adjustable positions. the U.S. 5,673,967A shows swiveling and telescopic footrests and the DE 20 45 958 A shows a simple chair with a seat that folds up.

Other manufacturers took the innovation out of the EP 0 911 008 B1 picked up, such as from the publication EP 1 743 612 B1 emerges. Here, the bearing below the seat is brought about by the fact that the end of the seat facing away from the backrest rests on a support in a linearly displaceable manner, so that this end can be pivoted on the support.

the JP 2010-69283 A describes a multi-axis robot arm that carries a seat and is arranged on a movable frame, but cannot be moved relative to the frame itself. More support frames for seats are from the publications U.S. 4,544,200A , GB 2 272 633 A and U.S. 2009/0218784 A1 known. Here various linear guides and Described pivot connections for attaching a seat to a frame.

A seat arrangement of the type described in the opening paragraph is known from European patent EP 2 621 443 B1 known to the applicant. A seat arrangement for physically handicapped people, in particular a wheelchair or a stroller, is described here, in which the fastening unit has at least one axial bearing through which one of the bars extends, the fastening unit has a pivotable coupling element for fastening the seat surface, and the coupling element is located between the two spars. The fastening unit described in this document extends between the two spars and has two opposite ends, with an axial bearing having a bearing bushing being arranged at each end, through which one of the spars protrudes. A helical spring pressing against the axial bearing presses the fastening unit into its initial position, ie towards a backrest of the seat unit. A pivot bearing is fastened to each axial bearing, which pivot bearing allows the fastening unit to be pivoted counter to a torsion spring, so that the rear edge of the seat surface can be pivoted upwards.

The ones from the EP 2 621 443 B1 known sliding bearing of the fastening unit for the seat shell has proven to be very stable and reliable in practice. However, the axial bearings used for the frame bars are complex and it is difficult to generate the necessary restoring forces, which move the fastening unit into the starting position, namely the angled sitting position.

The object of the invention is to propose a simple and reliable arrangement for the displaceable and pivotable attachment of the seat shell of the seat arrangement.

This object is achieved in that each strut and the attachment unit have guide elements that interact with one another for the displaceable and pivotable attachment of the seat surface to the frame have, which extend in the longitudinal direction of the spars and the elongated holes include connecting bolts projecting through.

In other words, the spar itself does not protrude through an axial bearing in the axial direction, but rather an elongated hole extending in the axial direction of the spar is provided for each spar, through which a connecting bolt protrudes that is displaceable in the longitudinal direction of the elongated hole. The connecting bolt has a round cross-section and is therefore also pivotably held in the slot. In this way, a high-strength and reliable connection of the fastening unit to the frame can also be achieved in a very simple and cost-effective manner, which enables the necessary degrees of freedom in the longitudinal direction of the rooms and in the pivoting direction.

In practice, the elongated holes can be arranged on the spars. The connecting bolts are then fastened to the fastening unit in such a way that they protrude through the elongated holes in the spars. The components used here are inexpensive and can be assembled very easily. For this purpose, each spar can have a tube and an insertion element which is inserted into the tube and has a bearing section which protrudes from the tube and in which the elongated hole is arranged. Non-round light metal tubes, for example oval tubes or rectangular tubes made of aluminum, are often used for the spar of a wheelchair frame. The insertion element can then be an elongate component consisting of an insertion section and a bearing section. The male portion has an outer perimeter that substantially conforms to the inner perimeter of the tube. At the end of the male portion is a shoulder or collar that projects outward at a right angle and the width of which is substantially equal to the wall thickness of the pipe. The bearing section of the plug-in element, in which the slot is fitted, adjoins this paragraph. Holes can be made in the male portion which align with holes in the tube. These holes can be penetrated by fastening screws or similar fasteners with which the spar is attached to the frame.

In practice, the connecting bolts can be covered with bearing sleeves. Bearing sleeves of this type are known both from metallic materials, e.g. bronze, and from synthetic materials, e.g. from polymer materials. For example, the company Igus GmbH sells a wide range of bearing sleeves made of polymer materials under the registered trademark iglidur. These bearing sleeves are the components that are mechanically loaded during the relative movement of the connecting bolts in the elongated holes. They can be easily replaced by dismantling the connecting bolts, removing the old bushings and replacing them with new ones. The bearing sleeves are very inexpensive components, so that the reliable storage of the connecting bolts in the elongated holes can be ensured in the long term by regularly replacing the bearing sleeves at low cost.

In practice, the fastening unit can be constituted by a fastening plate. The fastening unit then forms a flat component onto which the underside of a seat surface of a seat shell can be placed. The mounting plate stabilizes the seat. The lateral sections of the mounting plate can be angled and have bores for receiving the connecting bolts. By angling the lateral sections, the mounting plate is mechanically stiffened. At the same time, a symmetrical component is created, which is preferably held stably at the front end by means of the lateral sections. The rear portion of the mounting plate may rest on one or more bumpers.

In practice, the connecting bolts can have a bolt head on one side and a receiving means for a securing element on the other side. Such a configuration enables the bolts to be fitted very easily. The bolts are simply inserted through the holes in the components to be connected and, if necessary, through the bearing sleeve until their bolt head rests against an edge of one of the holes. A securing element is then inserted into the receiving means at the other end of the connecting bolt. The securing element can be a cotter pin, for example. In this case, the receiving means is a bore that protrudes diametrically through the bolt. The fuse element can also be an SL fuse or a circlip. In this case the receiving means is an annular groove on the circumference of the connecting bolt near its end.

In practice, a pressure body can be arranged in the elongated hole, which is pressed towards the backrest of the seat arrangement by a compression spring and which presses against the connecting bolt. The compression spring and the pressure body ensure that the connecting bolt is reliably pressed into the rearmost position in the elongated hole, which is closest to the backrest. This rearmost position corresponds to the upright sitting position. The seat shell is only stretched, i. i.e. the angle of the backrest to the seat is reduced. The backrest pivots around an axis in the area of the patient's shoulder, so that its lower end moves forward and upwards. As a result, the seat is pushed forward and pivots about an axis near its front end. If no such force is applied, the compression springs and pressure bodies on both sides push the connecting bolts to the rearmost position.

In practice, at least one elastic tensioning element can be attached to the attachment unit and to the frame, which pulls the attachment unit towards the backrest of the seat assembly. An additional force can be generated by this clamping element, which moves the fastening unit and thus the seat shell into the starting position. In particular, the tightening element can be a fastening strap or a fastening strap. Rubber-elastic belts or straps are very inexpensive components that generate a high level of elastic tension. Such a high elastic clamping force is desired in the seat arrangement described here in order to offer the patient accommodated in the seat arrangement sufficiently high stability.

In practice, at least one deflection roller can deflect the tensioning element. For example, an elastic round strap made of rubber can be attached with one end to the frame and with the second end to the front end of the mounting plate. In the rear area near the backrest, the elastic belt is deflected by one or two pulleys. Sliding the front end of the mounting plate forward tensions the strap so that it elastically retracts the mounting plate to the rearward, home position.

Fig. 1

eine dreidimensionale Ansicht der hier beschriebenen Sitzanordnung in Form eines Rollstuhls mit darauf angeordneter Sitzsschale;

Fig. 2

eine der Fig. 1 entsprechende Anordnung ohne Sitzschale;

Fig. 3

eine dreidimensionale Vorderansicht einer Befestigungsplatte und des angrenzenden Abschnitts des Rahmens der Sitzanordnung aus Fig. 2;

Fig. 4

eine schräge Draufsicht auf die Befestigungsplatte und dem Rahmen aus Fig. 2;

Fig. 5

eine dreidimensionale Explosionsansicht eines rechten Einsteckelements und der rechten vorderen und oberen Ecke des Rahmens aus Fig. 2 und 3;

Fig. 6

eine Ansicht einer Spannvorrichtung für die Befestigungsplatte von hinten und unten;

Fig. 7

ein Längsschnitt durch die Befestigungsplatte mit Spannvorrichtung;

Fig. 8

eine Vorderansicht der Befestigungsplatte mit Spannvorrichtung aus Fig. 6 und 7.

Further practical embodiments and advantages of the invention are described below in connection with the drawings. Show it:

1

a three-dimensional view of the seat arrangement described here in the form of a wheelchair with a seat shell arranged thereon;

2

one of the 1 corresponding arrangement without seat shell;

3

Figure 12 shows a front three dimensional view of a mounting plate and the adjacent portion of the frame of the seat assembly 2 ;

4

an oblique top view of the mounting plate and the frame 2 ;

figure 5

Fig. 12 shows a three dimensional exploded view of a right male element and the right front and top corner of the frame 2 and 3 ;

6

a view of a clamping device for the mounting plate from behind and below;

7

a longitudinal section through the mounting plate with clamping device;

8

a front view of the mounting plate with clamping device 6 and 7 .

the Figures 1 and 2 show a wheelchair with a side view of an L-shaped frame 1, which is arranged on a chassis 2. The chassis 2 has two rear wheels 3 with a rigid axle and two steerable front wheels 4 . In 1 a seat shell 5 is arranged on the frame 1 and has a backrest 6 and a seat surface 7 . The backrest 6 is approximately at shoulder height, ie articulated in the upper third to pivot on the vertical section of the frame 1 . It is pivotally connected to the seat 7 at its lower end.

In 2 the frame 1 with the chassis 2 is shown without the seat shell 5. The frame 1 is approximately L-shaped in side view. It comprises two lateral horizontal bars 10 and two lateral vertical struts 11. The lower ends of the vertical struts 11 are connected to the rear ends of the horizontal bars 10 via corner connectors 43. In 2 a fastening plate 8 arranged between the bars 10 can be seen, on which the seat surface 7 can be fastened with a quick connection (locking connection or buckle connection). The seat 7 is rigidly coupled to the mounting plate 8 so that the freedom of movement of the seat 7 corresponds to the freedom of movement of the mounting plate 8 .

The frame 1 further comprises a push bar 9 connecting the upper ends of lateral vertical struts 11 of the frame. Brakes can be arranged on the push bar 9 . At least the chassis 2 can be foldable in relation to the frame 1. Such features are widely known for wheelchairs and strollers and will not be described in detail here.

The pivoting attachment of the backrest 6 to the frame 1 at the level of the shoulders of the patient accommodated is achieved by articulating the upper part of the backrest 6 with the upper one Cross brace 44 between the lateral braces 11. The backrest 6 can therefore rotate about a horizontal axis in its upper third, so that its lower edge pivots forward. In connection with the fastening of the fastening plate 8 for the seat surface 7, which can be pushed forward and pivoted around the front edge, it is possible to open the seat shell 5 in the event of extension cramps in the patient. Without such muscle forces on the part of the patient, the seat shell is placed in the in 1 recognizable angled seating position pre-stressed.

The kinematics of the movement of the seat shell 5, in particular the seat surface 7 and the backrest 6 are detailed in the earlier patent applications EP 0 911 008 B1 and EP 2 621 443 B1 by the applicant, which is incorporated herein by reference. The novel mounting of the fastening plate 8 is described below, which enables the linear displacement and pivoting of the seat surface 7 of the seat shell 5 .

3 shows a three-dimensional front view of the fastening plate 8. The fastening plate 8 is held between two bars 10 of the frame 1 of the seat arrangement. For this purpose, pivot bearings for the front end of the mounting plate 8 that can be displaced in the longitudinal direction are provided in the front area of the bars 10 . Each of the bars 10 has a front bearing section 12 in which a slot 13 is arranged. The elongated hole 13 is penetrated by a connecting pin 14 which is accommodated in the elongated hole 13 so as to be displaceable in the longitudinal direction.

The details of these sliding bearings are particularly clear in the exploded view of the figure 5 to recognize. The bearing section 12 with the elongated hole 13 is part of an insertion element 15 which can be inserted with an insertion section 16 into the interior of an oval tube 17 which forms the rear section of the side rail 10 . The insertion section 16 has holes 18, 19 which are aligned with corresponding holes in the oval tube 17 and of fasteners such as screws or Bolts can be penetrated. The insertion element 15 is fixed in the oval tube 17 in this way. The outer cross section of the insertion section 16 essentially corresponds to the inner cross section of the oval tube 17. A resilient and stable connection between the insertion element 15 and the oval tube 17 of the side rail 10 is thus produced. The right rail 10 also has a corresponding plug-in element 15 . The spars 10 and the insertion elements 10 can in principle be constructed identically and only be arranged rotated by 180° around the longitudinal axis of the spars 10 .

As mentioned, the bearing section 12, in which the elongated hole 13 is located, is arranged in the front region of the insertion element 15, which protrudes from the oval tube 17. The elongated hole 13 extends in the vertical direction parallel to the longitudinal axis of the side rail 10. In side view, it has two semicircular end sections which are connected to one another by straight areas. The connecting pin 14 can be displaced along the straight areas.

A bearing sleeve 20 is pushed onto the connecting pin 14 and is guided in the elongated hole 13 with little play. The bearing sleeve 20 is preferably made of a low-friction material, such as a polymeric material or self-lubricating sintered metal. In the event of wear, the bearing sleeve 20 can be easily replaced. Bearing sleeves 20 can also be used which, in addition to the cylindrical sleeve, have a disc-shaped collar to give lateral guidance.

The laterally outer end of the connecting pin 14 has a pin head 21 . This fixes the connecting pin 14 on the outside of the bearing section 12. The connecting pin 14 protruding through the slot 13 is inserted through a receiving bore 22 which is arranged on an angled edge section 23 of the fastening plate 8, with the edge section 23 protruding downwards. The inserted through receiving hole 22 in the edge portion 23 and inside projecting end section of the connecting pin 14 has an annular groove 24 . The annular groove 24 forms a receiving means for a fuse element, in this case an SL fuse 25. Before the SL fuse 25 is attached, a washer 26 is fitted onto the end of the connecting pin 14. The connecting pin 14 is securely fixed within the elongated hole 13 and the receiving bore 22 on the fastening plate 8 by the washer 26 and the SL safety device 25 .

In figure 5 a pressure body 27 can also be seen, which can be inserted into an axial bore 28 on the end face 29 of the bearing section 12 . The pressure body 27 is pushed backwards by a compression spring 30 in the elongated hole 13 , ie towards the insertion section 16 and thus towards the backrest 6 of the seat shell 5 . The pressure spring 30 and the pressure body 27 thus press the connecting pin 14 elastically into the rear end of the elongated hole 13, which is close to the insertion section 16. After the pressure body 27 and the pressure spring 30 have been inserted, a cover plate 31 is screwed onto the end face 29 of the bearing section 12. For this purpose, two threaded holes 32 are provided in the end face 29 which interact with fastening screws 33 .

The fastening plate 8 is held pivotably in the region of its front edge by the connecting pins 14 . The rear portion of the mounting plate 8 rests on elastic buffers 34 in the 3 , 6 and 8th are recognizable. During an extension movement, in which the connecting pins 14 are pushed forward, the rear end of the mounting plate 8 is simultaneously lifted and moves away from the buffers 34. The elastic material of the buffers 34 prevents the mounting plate 8 from hitting without being cushioned when it is pulled back into the starting position by the clamping devices.

The compression springs 30, which press the connecting bolts 14 on both sides to the rear, are supported by an additional clamping device, which in the Figures 6 to 8 can be seen. The additional clamping device includes two elastic clamping elements 35, which of Round belts made of stretchable material, such as textile-coated rubber, are formed. The first end 36 of the tensioning element 35 is attached to a holder 37 which is fixed to a cross member 38 of the frame 1 . The holder 37 also carries a deflection roller 39 for the tensioning element 35. A second deflection roller 40 is attached to a holder 41 which is arranged on the mounting plate 8. The second end 42 of the clamping element 35 is fixed to the front of the mounting plate 8 . In particular 7 it can be seen that when the mounting plate 8 is moved forward, ie in 7 to the right, the clamping element 35 is lengthened and generates an elastic restoring force. The combination of the clamping force of the two clamping elements 35 and the two compression springs 30 can generate a sufficiently high restoring force to move the fastening plate 8 and thus the seat surface 7 of the seat shell 5 back into the angled starting position with sufficient force and hold it there , if no muscle force causes the seat shell 5 to stretch.

All components of the present fastening unit for the seat surface 7 of the seat shell 5 were selected with the aim of the greatest possible reliability and ease of assembly. In addition, value was placed on low production costs.

The features of the invention disclosed in the present description, in the drawings and in the claims can be essential both individually and in any combination for the realization of the invention in its various embodiments. The invention is not limited to the embodiments described. It can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art.

Reference List

1

frame

2

chassis

3

rear wheel

4

front wheel

5

seat shell

6

backrest

7

seat

8th

Fastening unit, fastening plate

9

handlebar

10

horizontal spar

11

vertical brace

12

storage section

13

Long hole

14

connecting pin

15

male element

16

plug-in section

17

oval tube

18

Hole

19

Hole

20

bearing sleeve

21

spigot head

22

mounting hole

23

downward angled edge section

24

Ring groove, recording medium

25

SL fuse, fuse element

26

washer

27

pressure hull

28

axial bore

29

face

30

compression spring

31

cover plate

32

threaded hole

33

mounting screw

34

buffer

35

Elastic tensioning element, round belt

36

first end

37

holder

38

cross member

39

pulley

40

pulley

41

holder

42

second end

43

corner connector

44

cross brace

Claims (11)

Seat arrangement with a frame (1) which has two mutually parallel bars (10) and a seat surface (7) which is arranged on the frame (1) and is attached to the frame (1) so that it can be displaced and pivoted in the direction of the bars (10). and with a fastening unit (8) which slidably and pivotably fastens the seat (7) to at least one of the bars (10), characterized in that each bar (10) and the fastening unit (8) for the slidable and pivotable fastening of the Seat surface (7) on the frame (1) have guide elements which interact with one another and which comprise elongated holes (13) running in the longitudinal direction of the bars (10) and connecting bolts (14) projecting through the elongated holes. Seat arrangement according to Claim 1, characterized in that the elongated holes (13) are arranged on the bars (10). Seat arrangement according to Claim 2, characterized in that each beam (10) has a tube (17) and an insertion element (15) which is inserted into the tube (17) and has a bearing section (12) protruding from the tube (17), in which the slot (13) is arranged. Seat arrangement according to one of the preceding claims, characterized in that the connecting bolts (14) are encased in bearing sleeves (20). Seat arrangement according to one of the preceding claims, characterized in that the fastening unit is formed by a fastening plate (8). Seat arrangement according to Claim 5, characterized in that the lateral sections of the fastening plate (8) are angled and have bores (22) for receiving the connecting bolts (14). Seat arrangement according to one of the preceding claims, characterized in that the connecting bolts (14) have a bolt head (21) on one side and a receiving means for a securing element (25) on the other side. Seat arrangement according to one of the preceding claims, characterized in that a pressure body (27) is arranged in the elongated hole (13), which is pressed towards a backrest (6) of the seat arrangement by a compression spring (30) and which presses against the connecting bolt (14 ) presses. Seat arrangement according to one of the preceding claims, characterized in that at least one elastic tensioning element (35) is fastened to the fastening unit (8) and to the frame (1), which pulls the fastening unit (8) towards the backrest (6) of the seat arrangement. Seat arrangement according to Claim 8, characterized in that the tensioning element (35) is a fastening strap or a fastening belt. Seat arrangement according to Claim 9 or 10, characterized in that at least one deflection roller (39, 40) deflects the tensioning element (35).

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