Title of Invention

AUTOMOBILE VEHICLE SEAT WITH ADJUSTABLE SEAT PAN

Abstract

An automobile vehicle seat comprising a seat framework attached to the floor of a vehicle, a seat pan (10) installed so as to be movable in relation to the seat framework by means of a front crossmember (16) in the form of a balance beam, installed so as to pivot on the seat framework between a lowered position and a raised position and at least one sliding pivot {17). The seat pan (10) is installed so as to pivot on a main shaft (160) of the front crossmember (16). The sliding pivot is placed towards the rear of the seat pan (10) and has a translation direction oriented upwards and rearwards in such a way that when the front crossmember (16) goes from lowered position to raised position the seat pan (10) moves rearwards and upwards. Figures 2 and 3

Full Text

Automobile vehicle seat with adjustable seat pan The invention relates to an automobile vehicle seat with an adjustable seat pan, especially adjustable- in height and length. An automobile vehicle seat often comprises adjustment means to adapt its position and its shape to the morphology of the user of the seat. For tall persons, the seat pan can sometimes be placed at a low height so that the eyes of the user will be at the correct height in relation to the windshield bay of the vehicle and with a fairly large distance between the nose of the seat pan and the backrest to support the thighs of the user over a long length. For small persons, on the contrary, the seat pan is placed fairly high so that the eyes of the person will be also at the correct height and with a fairly short distance between the nose of the seat pan and the backrest so that the nose will not be in contact with the inside of the knees. A seat is known by document WO 02/074575 where the framework of the seat pan in rectangular frame form , is installed as to be movable in relation to a seat framework comprising movable slide profiles. The frame is installed on four links so that the links, the frame and the profiles form two deformable parallelograms to adjust the height of the seat pan in relation to the slides. The installation of the frame on the slides is not easy. Indeed, before installation, each link pivors freely and the operator must hold the frame and each of the links in place before attaching the last pivots of the links either to the frame or to the slides. This is why, a special tool intended to facilitate this installation is often used. The number of parts required is high. On account of its complexity or of the need to use a special tool, the assembly of the frame on the slides is not compatible with the requirements of just-in-time installation as close as possible to the vehicle assembly line. Indeed, in just-in-time installation operations, it is better not to use special tools. The framework of the seat must therefore be installed previously and then transported before performing the final operations. Such a framework is bulky for its transport. The aim of the present invention is to provide an automobile vehicle seat where the height and depth of the seat pan are adjustable with a mechanism which is simple and where the final installation operations of the framework or of the seat can be done as quickly as possible using a minimum of tools. With these aim in mind, the object of the invention is an automobile vehicle seat comprising a seat framework intended to be attached to the floor of a vehicle, a seat pan installed so as to be movable in relation to the seat framework by seat pan connecting means, a front crossmember in the form of a balance beam installed so as to pivot on the seat framework between a lowered position and a raised position, the seat pan being installed so as to pivot on the main shaft of the front crossmember. The seat pan connecting means also comprise at least one slidir g pivot placed at the rear of the seat pan and with a translation direction oriented upwards and rearwards in such a way that, when the crossmember goes from the lowered position to the raised position, the seat pan moves rearwards and upwards. When the seat is viewed from the side, that is in transverse direction, it can be seen that the front of the seat pan moves along an arc centred on the axis of the front crossmember between the lowered position and the raised position. At the same time, the rear of the seat pan moves in the sliding pivot translation direction. By the combination of these two guidances, a global movement of the seat pan is obtained in translation upwards and rearwards passing from the lowered position to the raised position. Only the seat pan is movable. The movement of the seat pan allows the adjustment both of the height of the seat pan surface and its length so that it can be adapted to the morphology of its occupant. The front crossmember combines the functions of the two rods and is thus easier to install than two parts with independent movements. Also, the installation of a sliding pivot is easier than that of the links as will be seen better below. According to a specific arrangement, the axis of the main shaft is located more or less at the vertical above the pivoting axis of the front crossmember when the front crossmember is in raised position. Thus, in raised position, the front of the seat pan is positioned as high as possible. According to another arrangement, the axis of the main shaft is located at the front of the pivoting axis of the front crossmember when the front crossmember is in lowered position. Thus, in combination with the seat pan lowering movement, passing from the raised position to the lowered position, the nose of the seat pan moves forwards in such a way that the distance between the nose and the backrest increases. Conversely, when going from the lowered position to the raised position, the nose of the seat pan is moved rearwards in such a way that the distance between the nose and the backrest decreases. According to a specific arrangement, the front crossmember comprises a tube forming the main shaft, an arm connecting in a fixed manner the main shaft to a pivot allowing the pivoting of the front crossmember on the framework of the seat. The arm is, for example, assembled by welding to the main shaft and to the pivot. In a specific manner, the seat comprises an adjustment mechanism to adjust and maintain the position of the front crossmember between the lowered position and the raised position. The occupant of the seat can thus adjust at wish the position of the seat pan in all intermediary positions. This mechanism can be of various types, especially among the types used conventionally to adjust the tilt angle of a backrest. More especially, the mechanism comprises a gear wheel which meshes with a toothed quadrant attached to the front crossmember. The reduction ratio between the movement of a control lever and the pivoting of the front crossmember can be adjusted in a freer manner during the design of the seat. Moreover, the position of the axis of the gear wheel can also be adjusted and is not necessarily in the pivoting axis of the front crossmember. In a variant, when the front crossmember comprises the arm, the latter is a flange, the mechanism comprises a gear wheel which meshes with a toothed quadrant made in the flange. According to an improvement, the seat pan comprises a framework made from a metal sheet, the framework comprising an indentation in which the main shaft is housed, at least a cap maintaining the main shaft in the indentation. The form of a bearing is thus made directly on the seat pan framework which simplifies the making of the bearing. According to a specific arrangement, the sliding pivot comprises a pin attached to the seat pan and installed so as to slide and pivot in a slot of the seat pan framework. The slot guides the pin and determines its more or less straight trajectory. However, it can be considered to give a specific shape to the slot such as an arc of circle. According to an embodiment, the framework of the seat comprises two movable slide profiles for the longitudinal adjustment of the position of the seat, two bearings attached respectively to one of the movable profiles, the front crossmember being installed so as to pivot on the bearings and a rear support bearing the sliding pivots, the rear support and the bearings being attached to the profiles. The assembly of the slide profiles allows the seat framework to be made with a first subassembly comprising the rear support and the backrest and a second subassembly comprising the bearings and the front crossmember. These two subassemblies can then be attached, for example by screwing onto the profiles, so as to form the framework of the seat. The seat pan is then added to this assembly. Possibly, the seat pan is assembled to the second subassembly before the assembly of the seat. This design allows the subassemblies to be prepared and delivered to an assembly workshop as near as possible to the vehicle manufacturing plant, limiting the number of operations in this workshop and the tools required. In this way, the constraints of a just-in-time organisation are met as best as possible. The subassemblies are sufficiently compact to limit their overall sizes when they are stored or transported in number. According to an improvement, the seat comprises at least one spring acting between the framework of the seat and the seat pan tending to bring the front crossmember to the raised position. The adjustment mechanism is thus relieved of a significant part of the forces when an occupant occupies the seat. Other features and advantages will become apparent on reading the following description. The description refers to the accompanying drawings, on which: FIG. 1 is a perspective view of the framework of a seat in compliance with a first embodiment of the invention, FIGS. 2 and 3 are side views of the seat of FIG. 1 in a lowered position and in raised position respectively, FIG. 4 is a perspective view of the seat of FIG. 1 seen from another angle, FIG. 5 is a partial cross-sectional view through line V-V of FIG. 1, FIG. 6 is a view similar to FIG. 4 of a second embodiment of the invention. A seat 1 according to a first embodiment of the invention comprises a seat pan 10 extending more or less horizontally and a backrest 11 extending more or less vertically from the rear of the seat pan 10 and above it. The seat 1 is intended to be installed so as to slide on the floor of an automobile vehicle by means of slides 12 ensuring the longitudinal adjustment of the position of the seat, known themselves- The front of the seat being the direction in which an occupant of the seat looks when sat on the seat pan 10 with his/her back in contact with the backrest 11. The seat 1 comprises a seat framework, as shown on FIGS. 1 and 4 for example. The seat framework comprises a rear support 13 on which the backrest 11 is installed so as to pivot. The support 13 is attached to two movable profiles 120 of the slides 12, The support 13 comprises two lateral flanges 130 attached to each other by a rear crossmember 131. The seat framework also comprises two bearings 14, 15 attached respectively to one of the movable profiles 12 0. A front crossmember 16 in the form of a balance beam is installed so as to pivot on the bearings 14, 15 between a lowered position, as shown on FIG. 2, and a raised position, as shown on FIG. 3. The seat pan 10 is installed so as to be movable in relation to the seat framework by seat pan connecting means which comprise two sliding pivots 17 and the front crossmember 16. More precisely, each sliding pivot 17 comprises a pin 101 attached to the seat pan 10. The pin 101 is installed so as to slide and pivot in a slot 132 of the rear support 13 made in one of the flanges 130, as is especially shown on FIG. 5. Thus, the sliding pivot 17 is placed towards the rear of the seat pan 10. The slot 132 has a translation direction oriented upwards and rearwards. Moreover, the seat pan 10 comprises a seat pan framework 100 made from a metal sheet so as to form a sort of bucket which accommodates a seat pan cushion, not shown and composed in a conventional manner. On the front part, the seat pan 10 comprises a transverse semi-cylindrical indentation 103 in which the main shaft 160 of the front crossmember 16 is housed and installed so as to pivot. The main shaft 160 is held in the indentation 103 by two caps 104 added to the seat pan framework 10 0 and of semi-cylindrical shape complementary with the indentation 103. At the rear, the seat pan comprises a crossbar 102 which at its ends bears the pins 101. The pins 101 are attached, for example by screwing, to the crossbar 102 being put into place from the outside of the seat through the slots 132. This screwing operation requires no special tools and is compatible with the operations of a just-in-time installation. This simple screwing operation can also be done after the furnishing of the seat pan. The seat 1 also comprises an adjustment mechanism 19 to adjust and maintain a position of the front crossmember 16 between the lowered position and the raised position. The adjustment mechanism 19 is attached to one of the bearings 14 and comprises a gear wheel 190 which meshes with a toothed quadrant 161 attached to the front crossmember 16 as can be seen especially on FIG. 4. The mechanism 19 is designed so that it can control the rotation of the gear wheel 190 and maintain the position of the gear wheel 190 when no control action is made on the mechanism 19. The mechanism 19 shown has a manual control but an electrical control could be used. The seat also comprises two springs 18 acting between the support 13 at the rear crossmember 131 and the seat pan 10 at the crossbar 102 tending to bring the seat pan 10 towards the rear. When the front crossmember 16 is in lowered position, the axis of the main shaft B is located at the front of the pivoting axis A of the crossmember 16. The pins 101 are placed at the front end 132a of the slots 132. When the occupant of the seat acts on the mechanism 19 to pivot the crossmember in the direction shown by arrow Fl, the front crossmember 16 is oriented towards the raised position in such a way that the axis of the main shaft B moves upwards and rearwards. The main shaft 160 drives the front part of the seat pan 10 upwards and rearwards which causes the pins 101 to slide in the slots 132 also upwards and rearwards. The springs 18 participate to facilitate this movement. The movement can be continued up to the raised position in which the axis of the main shaft B is located more or less vertically above the pivoting axis A of the front crossmember 16. In this position, the pins 101 are placed at the other end 132b, at the highest and most rearward position of the slots 132. Thus, the seat pan 10 has made a global upwards and rearwards movement without significantly changing tilt angle. The occupant of the seat can control the reverse movement and stop the movement in any intermediary position between the lowered position and the raised position. In a second embodiment of the invention, the front crossmember 16' is not made of a single tube but the main shaft 160' is connected to a pivot 162 by means of a flange 161' comprising the toothed quadrant as shown on FIG. 6. The operation is the same as that of the first embodiment. CLAIMS 1. Automobile vehicle seat comprising a seat framework intended to be attached to the floor of a vehicle, the seat pan (10) installed so as to be movable in relation to the seat framework by seat pan connecting means (17, 16) characterised in that the seat pan connecting means comprise a front crossmember (16) in the form of a balance beam, installed so as to pivot on the seat framework between a lowered position and a raised position, the seat pan (10) being installed so as to pivot on a main shaft (160) of the front crossmember (16), and in that the seat pan connecting means comprise, among other things, at least one sliding pivot (17) placed towards the rear of the seat pan (10) and with a translation direction oriented upwards and rearwards in such a way that when the front crossmember (16) goes from the lowered position to the raised position, the seat pan (10) moves rearwards and upwards. 2. Seat according to claim 1 where the axis of the main shaft (B) is located more or less vertically above the pivoting axis (A) of the front crossmember (16) when the latter is in raised position. 3. Seat according to claim 1 where the axis of the main shaft (B) is located at the front of the pivoting axis (A) of the front crossmember (16) when the latter is in lowered position. 4. Seat according to claim 1 where the front crossmember (16) comprises a tube forming the main shaft (160), an arm (161') connecting in a fixed manner the main shaft (160) to a pivot (162) allowing the pivoting of the front crossmember (16) on the seat framework. 5. Seat according to claim 1, characterised in that it comprises an adjustment mechanism (19) to adjust and maintain the position of the front crossmember (16) between the lowered position and the raised position. 6. Seat according to claim 5 where the mechanism (19) comprises a gear wheel (190) which meshes with a toothed quadrant (161) attached to the front crossmember (16) . 7 . Seat according to claims 4 and 5 taken in combination where the arm is a flange (161'), the mechanism (19) comprises a gear wheel (190) which meshes with a toothed quadrant made in the flange (161')- 8. Seat according to claim 1 where the seat pan (10) comprises a seat pan framework (100) made from a metal sheet, the framework comprising an indentation (103) in which the main shaft (160) is housed and at least one cap (104) holding the main shaft (160) in the indentation (103). 9. Seat according to claim 1 where the sliding pivot (17) comprises a pin (101) attached to the seat pan (10) and installed so as to slide and pivot in a slot (132) of the seat framework. 10. Seat according to claim 1 where the seat framework comprises two movable profiles (120) of the slide (12) which ensures the longitudinal adjustment of the position of the seat, two bearings (14, 15) attached respectively to one of the movable profiles (120), the front crossmember (16) being installed so as to pivot on the bearings (14, 15) and a rear support (13) bearing the sliding pivots (17), the rear support (13) being attached to the two movable profiles (120). 11. Seat according to claim 1, characterised in that it comprises at least one spring (18) acting between the seat framework and the seat pan (10) tending to bring the front crossmember (16) into the raised position.

Documents:

2670-CHE-2007 CORRESPONDENCE OTHERS 14-07-2011.pdf

2670-CHE-2007 OTHER PATENT DOCUMENT 19-09-2011.pdf

2670-CHE-2007 POWER OF ATTORNEY 28-09-2011.pdf

2670-CHE-2007 CORRESPONDENCE OTHERS 28-09-2011.pdf

2670-CHE-2007 EXAMINATION REPORT REPLY RECIEVED 19-09-2011.pdf

2670-CHE-2007 FORM-3 19-09-2011.pdf

2670-CHE-2007 AMENDED CLAIMS 19-09-2011.pdf

2670-che-2007-abstract.pdf

2670-che-2007-claims.pdf

2670-che-2007-correspondnece-others.pdf

2670-che-2007-description(complete).pdf

2670-che-2007-drawings.pdf

2670-che-2007-form 1.pdf

2670-che-2007-form 3.pdf

2670-che-2007-form 5.pdf