Patent Application
20110181086
This application claims the priority benefit of European Patent Application No. EP 10405014, filed on Jan. 22, 2010, the entirety of which is hereby incorporated by reference.
1. Field of Invention
The invention relates to a support structure for a back part and/or a seat of a seat assembly and to a seat assembly comprising such a support structure.
2. Related Art
For the most part, seat assemblies, for example chairs, have a modular structure: in addition to a seat and a back part, if necessary, which can comprise a backrest, for example, they normally also comprise a support structure for the respective back part and/or the respective seat, wherein it is the object of the support structure to hold the seat and the back part, if necessary, in a certain position and to accommodate a load, which can be transferred onto the seat or the back part, respectively, by a person sitting on the seat assembly, for example, and to hold the seat and the back part, if necessary, in a stable position in each case in response to the impact of the respective load.
Oftentimes, seat assemblies are not embodied so as to be rigid. Oftentimes, the respective support structure is constructed such that even though the support structure can be positioned in the room in a stationary manner, the spatial position of the respective back part and/or of the respective seat can be changed relative to the support structure. This provides for the possibility, for example, that the spatial arrangement of the back part and/or of the seat can be adapted to the respective posture of a person, who sits on the respective seat assembly and who constantly changes his posture, on the one hand, or to achieve, for example, that the same seat assembly can be adjusted to different requirements of different persons, who can differ with regard to their height or weight or with regard to their preferred posture when sitting. For this purpose, a conventional support structure of a seat assembly usually comprises a base support, which can be positioned in a stationary manner in the room, and at least one support part, which is arranged on the base support and which is attached to the base support such that a movement of the support part can be carried out relative to the base support. The purpose of said support part is to hold the back part and/or the seat in a position, which is a function of the relative position of the support part with respect to the base support. The back part or the seat, respectively, must thereby not be attached directly to the support part: the back part or the seat, respectively, can in each case be connected to said support part or can be coupled to the support part via one or a plurality of other components.
A support structure of the afore-mentioned type can also be equipped with a power system for generating at least one reset force, which is generated in response to the respective movement of the support part and which is directed opposite to this movement. For example, such a power system can comprise one or a plurality of spring elements, which are in each case coupled to the base support and the support part such that the spring element generates a reset force, which is directed opposite to the respective movement of the support part in response to the respective movement. Such a power system ensures a flexible arrangement of the back part or of the seat, respectively, such that the respective back part and/or the respective seat are deflected out of a predetermined position of equilibrium, if necessary, in response to the impact of a force, wherein the support part is at the same time deflected out of a predetermined position of equilibrium and a reset force, which counteracts the deflection of the support part, is generated. As a rule, the respective reset force is thereby greater, the further the support part is deflected out of the original position of equilibrium. Due to the fact that the power system generates a reset force, which is directed opposite to the respective movement of the support part, the support part can subsequently assume a new position of equilibrium as soon as all of the forces acting on the support part compensate one another. In so doing, the back part or the seat, respectively, can in each case be held in a position of equilibrium, which is a function of the respective stress of the back part or of the seat, respectively. The latter ensures a high seating comfort, the more so as the rear part and/or the seat can in each case be adapted to the current posture of a person sitting on the seat assembly and the respective reset force created by the power system in each case acts as a support for the person, who is sitting down.
To even further improve the seating comfort, which is ensured by a power system of the afore-mentioned type, such a power system can be designed such that the size of the reset force, which the power system generates in response to a certain deflection of the support part out of a predetermined position of equilibrium, can be varied to a certain extent and can be adjusted, as needed. The latter allows for the power system to be adapted to different requirements. As a rule, an adjustment of the power system in which the power system generates a relatively large reset force in response to a predetermined deflection of the support part (“hard” adjustment of the power system), is appropriate in the case of tall or heavy persons, respectively, for example, while in the case of short or light persons, respectively, an adjustment of the power system in which the power system generates a relatively small reset force in response to a predetermined deflection (“soft” adjustment of the power system) would be more suitable.
A seat assembly, which comprises a changeable power system of the afore-mentioned type, is known from EP 1486142 A1. This seat assembly, a chair, encompasses a support structure in combination with a power system of the afore-mentioned type. In this case, the power system comprises an elastomer torsion spring element, which serves the purpose of generating a reset torque, which counteracts a pivoting motion of a support for a seat (referred to hereinbelow as “seat support”, if applicable) about an axis of rotation. The elastomer torsion spring element includes an inner housing and an outer housing, wherein an elastomer body is integrated in a space between the inner housing and the outer housing. On its outer side, the inner housing encompasses a contact surface, on which the elastomer body is in contact with the inner housing and on its inner side, the outer housing encompasses contact surface, on which the elastomer body is in contact with the outer housing. The elastomer body is thereby fixedly connected to the respective contact surface of the inner housing and of the respective contact surface of the outer housing, so that the elastomer body can neither slip on the contact surface of the inner housing nor on the contact surface of the outer housing relative to the inner housing or to the outer housing. In the instant case, the outer housing and the inner housing are embodied in a cylindrical manner and are oriented coaxially to one another. The outer housing is held on a support structure of the chair, while the inner housing sits on a shaft in a torque proof manner, with said shaft being capable of rotating about its longitudinal axis. A seat of the chair is coupled to the shaft such that the shaft is rotated about its longitudinal axis and the seat is pivoted out of a predetermined basic position in the event that the seat is loaded by the weight of a person. Due to the rotation of the shaft, the inner housing is rotated about its longitudinal direction and is thereby twisted relative to the outer housing with the effect that the elastomer torsion spring element generates a reset torque, which acts on the shaft or on the seat, respectively, and which counteracts the rotation of the shaft or the pivoting motion of the seat, respectively, and which increases as the angle of rotation increases. In the case of the torsion spring element, the size of the minimal torque acting on the shaft when the seat is pivoted out of the mentioned basic position (referred to hereinbelow as “minimum reset torque”) can be changed. For this purpose, the outer housing can be rotated about its longitudinal axis by means of a rotating mechanism, which is arranged on the support structure of the chair, and can thus be rotated about the longitudinal axis of the shaft, wherein the outer housing is twisted relative to the support structure of the chair and relative to the inner housing or to the shaft, respectively. The elastomer torsion spring element is prestressed by means of the twisting of the outer housing relative to the inner housing, wherein the angle or rotation, about which the outer housing is twisted relative to the inner housing when the seat is located in the basic position, determines the size of the “minimum reset torque”.
The power system of the afore-mentioned seat assembly has different disadvantages. The mentioned elastomer torsion spring element has the disadvantage that the reset torque, which is generated in response to a rotation of the mentioned shaft about a certain angle of rotation, shows a relatively low increase as function of the respective angle of rotation, in particular when the elastomer torsion spring element is not or only slightly prestressed. According thereto, the outer housing of the elastomer torsion spring element must be twisted about a relatively large angle of rotation relative to the inner housing and the elastomer body of the elastomer torsion spring element must be prestressed to a relatively large extent when a large minimum reset torque is to be adjusted, so as to be able to provide an adequate seating comfort to persons with a heavy weight, e.g. In response to the twisting of the outer housing of the elastomer torsion spring element relative to the inner housing, a relatively large force must be applied when the elastomer body is to be prestressed to a large extent so as to achieve the highest possible reset torque. It is thus time-consuming and laborious to vary the minimum reset torque by manually twisting the outer housing relative to the inner housing across a large area. The reset torque generated by the elastomer torsion spring element further increases in a highly non-linear manner (progressively) as a function of the angle of rotation of the shaft when the shaft is to be rotated about an angle of rotation in the range of from 0 to approx. 70°, for example. In the area of the upper end of the mentioned area of the angle of rotation, the elastomer body is already prestressed to such an extent that damages to the elastomer body must be expected in response to a further increase of the angle of rotation. The minimum reset torque of the elastomer torsion spring element can thus only be increased up to a certain upper limit. The resilience of the power system is thus limited.
It is an object to avoid the abovementioned disadvantages and to create a support structure or a seat assembly, respectively, comprising a power system, which makes it possible to be able to change the reset force, which is in each case generated by the power system, across the largest possible range in a simple and comfortable manner, so that the power system can be adapted to the requirements of different persons with large differences with regard to their weight in a simple and comfortable manner.
This and other objects are solved by means of a support structure for a back part and/or a seat of a seat assembly, and by means of a seat assembly including such a support structure.
According to an embodiment of the invention, the support structure comprises a base support, at least one support part, which is arranged on the base support, for supporting and/or holding the respective back part and/or the respective seat, with said support part being attached to the base support such that a movement of the support part relative to the base support can be carried out, and a power system for generating at least one reset force, which is generated in response to the respective movement of the support part and which is directed opposite to this movement. The power system thereby comprises at least a first spring element, which is coupled to the base support and to the support part such that, in response to the respective movement of the support part, the first spring element generates a first reset force, which is directed opposite to the movement of the support part.
The support part is thereby embodied to hold the respective back part and/or the respective seat of the respective seat assembly in a position, which is a function of the relative position of the support part with reference to the base support. The back part or the seat, respectively, must thereby not be attached directly to the support part: the back part or the seat, respectively, can in each case be connected to the mentioned support part or coupled to the support part via one or a plurality of other components.
According to an embodiment of the invention, the power system additionally comprises at least a second spring element and at least one coupling device for coupling the respective second spring element to the base support and/or to the support part, with said coupling device being capable of being brought either into a first or into a second state, wherein
Accordingly, the power system of the support structure according to an embodiment of the invention comprises different groups of spring elements comprising different functions: one or a plurality of “first” spring elements and one or a plurality of “second” spring elements.
The respective first spring element is thereby in each case coupled to the base support and to the support part and generates a (“first”) reset force, which in each case acts on the support part, when the support part is moved relative to the base support. In the event that the power system comprises a plurality of first spring elements of this type, the totality of all of the first spring elements generates a reset force, which acts on the support part and which corresponds to the sum of the reset forces, which are generated by the respective first spring elements.
However, the respective second spring element can either be coupled to the base support as well as to the support part—as a function on the respective state of the coupling device—or (in each case as a function of the respective realization of the coupling device) it can be decoupled at least from the base support or at least from the support part or from the base support as well as from the support part. The respective second spring element only generates a (“second”) reset force, which acts on the support part—in addition to the reset force, which is generated by the respective first spring elements—when the support part is moved relative to the base support when the coupling device is in a state, in which the respective second spring element is coupled to the base support as well as to the support part. In the other state of the coupling device, the respective second spring element cannot generate a reset force, which acts on the support part—due to the decoupling from the base support and/or from the support part.
In the event that the power system comprises a plurality of second spring elements of this type, the totality of all second spring elements generates a reset force, which acts on the support part and which corresponds to the sum of all reset forces being generated by those second spring elements, which are currently coupled to the base support as well as to the support part by means of the respective coupling devices.
Accordingly, a reset force, which corresponds to the sum of all of the (“first” and “second”) reset forces generated by the respective first and second spring elements, acts on the support part in each case.
According to an embodiment of the invention, the reset force acting on the support part can be changed by changing the state of the respective coupling device, wherein the number of those second spring elements, which are currently coupled to the base support as well as to the support part, is changed in each case.
The reset force acting on the support part (in response to a predetermined deflection of the support part out of a basic position), can thereby be varied in a range, the size of which is substantially a function of the number of the respective second spring elements and of the respective characteristics of the respective second spring elements. Due to the fact that the number of the respective second spring elements can on principle be chosen randomly, the invention allows for the variation of the reset force, which acts on the support part, in any range, by means of suitably selecting the number of the second spring elements and by suitably selecting the characteristics of the respective spring elements. The characteristics of the respective spring elements can thereby be chosen such that none of the spring elements can be overloaded. The support structure according to an embodiment of the invention can thus in each case be designed such that the support structure can be adapted to the requirements of different persons having large differences with regard to their weight. In the event that the support structure is to be adjusted to a person having a relatively small weight, the respective coupling devices can in each case be brought into a state, for example, in which none of the respective second spring elements is coupled to the base support as well as to the support part. In this case, only the respective first spring elements contribute to the reset force, which acts on the support part. In the event, however, that the support structure is to be adjusted to a person having a relatively large weight, the respective coupling devices can be brought into a state, for example, in which the respective second spring elements are coupled to the base support as well as to the support part. In this case, all of the first and second spring elements contribute to the reset force, which acts on the support part.
Advantageously, there are no limitations with reference to the selection of the respective spring elements: on principle, any type of spring elements can be used to realize the support structure according to the invention, e.g. spring elements, which comprise an elastically deformable body, or pneumatic or hydraulic spring elements, or spring elements, which can be loaded by means of a torsion or a pressure or a tension, or other spring elements.
The respective coupling device can be realized in many ways, for example with mechanical means, electromechanical, magnetic, pneumatic, hydraulic or other means.
Advantageously, the coupling device can be realized such that movements, which must be carried out opposite to a force, which is generated by the respective second spring element, are not necessary in response to the coupling of the respective second spring element to the base support or to the support part, respectively, or in response to the decoupling of the respective second spring element from the base support or from the support part, respectively. As a rule, the respective coupling device can thus be brought from one of the respective states into a different state quickly, with a small expenditure of force and thus comfortably for a user.
An embodiment of the support structure according to the invention comprises a control device for impacting the respective state of the respective coupling device such that the respective coupling device can either be brought into the first or the second state. Such a control device makes it possible for a user to comfortably bring the coupling device into the different states, without having to touch the coupling device or the respective spring element, which is to be coupled to the base support or the support part, respectively, by means of the coupling device. This is so because, as a rule, the coupling device or the respective spring element is not easily accessible to a user. The control device makes it possible for a user to control the respective coupling device in a simple and comfortable manner, for example when sitting on the respective seat assembly. Such a control device is advantageous, in particular, when a plurality of coupling devices are available and must be controlled independent on one another. Such a control device can be realized in many different ways, for example by means of mechanical, electromechanical, electrical, pneumatic, hydraulic or other means (in each case depending on the construction and the function of the respective coupling devices).
An embodiment of the support structure according to the invention comprises a plurality of second spring elements and a plurality of coupling devices, wherein two different coupling devices can in each case be brought into the first or the second state independent on one another. In this case, a plurality of second spring elements can be coupled to the base support or to the support part, respectively, independent on one another and can be decoupled from the base support and/or from the support part. In an alternative of this embodiment, the support structure can be embodied such that the respective second spring elements a) can in each case be brought into a state, in which none of the second spring elements is coupled to the base support and to the support part or b) can in each case be brought into a state, in which one of the second spring elements is coupled to the base support and to the support part, or c) can in each case be brought into a state, in which a plurality of the second spring elements are coupled to the base support and to the support part. Based on a state, in which none of the second spring elements is coupled to the base support as well as to the support part, this embodiments makes it possible to successively increase the number of the second spring elements, which are coupled to the base support and to the support part, by impacting the respective coupling device and to thus increase the reset force, which can be generated by means of the power system, step by step in a plurality of steps. This embodiment has the advantage that the power system can be adapted to the respective weight of different persons in a particularly fine and accurate manner, namely for a range of weights, which is greater, the greater the number of the second spring elements.
As a rule, the respective spring elements are constructed such that the generation of a reset force is connected to a change of the extension of the respective spring element in at least one direction.
An embodiment of the support structure is accordingly characterized in that the respective second spring element encompasses a first section and a second section, with said sections being capable of being moved relative to one another for generating the respective reset force. The coupling device further comprises:
This embodiment has the advantage that the coupling device can be realized with simple means (based on holding means). A movement of the support part relative to the base support in each case acts on that second spring element, the first section of which is held by the first holding means and the second section of which is held by the second holding means, such that the first section of this second spring element is moved in response to a movement of the support part relative to the second section of the second spring element, so that the second spring element inevitably generates a reset force, which acts on the support part.
An advantageous alternative of the aforementioned embodiment is designed such that the first holding means of the respective coupling device is embodied to hold the first section of the respective second spring element so as to be capable of being detached and—in the event that the coupling device is brought into the second state—is brought into a state, in which the first section of the respective second spring element is detached from the respective first holding means in response to the respective movement of the support part, and/or that the second holding means of the respective coupling device is embodied for holding the second section of the respective second spring element so as to be capable of being detached and—in the event that the coupling device is brought into the second state—is brought into a state, in which the second section of the respective second spring element is detached from the respective second holding means in response to the respective movement of the support part. To achieve that the respective second spring element is not coupled to the base support and to the support part and to accordingly not generate a reset force, the coupling device must be equipped such that the second spring element is detached from the first holding means and/or from the second holding means. It is thus not necessary for the first holding means as well as the second holding means to be embodied as means for detachably holding, so as to provide for a decoupling of the second spring element from the base support or from the support part, respectively. When the second holding means is designed such, for example, that it can hold the second section of the second spring element so as to be capable of being detached, the first holding means can then also be embodied such that it establishes a fixed, rigid connection, if necessary, between the second section of the second spring element and the base support.
If, on the other hand, the first holding means is designed such that it can hold the first section of the second spring element so as to be capable of being detached, the second holding means can then also be embodied such that it established a fixed, rigid connection, if necessary, between the first second of the second spring element and the support part.
In a further development of the afore-mentioned embodiment of the support structure, the first holding means can be a movable part, for example, which can be brought into at least two different positions, wherein the first holding means, in one of these positions, is in contact with the first section of the respective second spring element such that this first section is held in the predetermined position relative to the base support, and is separated from the first section of the respective second spring element in the other one of these positions. Accordingly, the second holding means can be a movable part, which can be brought into at least two different positions, wherein the second holding means, in one of these positions, is in contact with the second section of the respective second spring element such that this second section is held in the predetermined position relative to the support part and is separated from the second section of the respective second spring element in the other one of these positions.
The support structure can comprise an actuating means for moving the respective holding means from one of these positions into another one of the positions. The actuating means makes it possible for the user to move the respective holding means in a simple manner and to thus impact the respective state of the coupling device. In the event that the support structure comprises a plurality of second spring elements and accordingly a plurality of first and second holding means for holding the respective second spring elements, it is advantageous to design a single actuating means such that all of the movable holding means can be moved with this actuating means independent on one another.
The actuating means can be a rotatable cam shaft, for example, on which at least one cam, which is assigned to the respective holding means, is arranged such that the respective holding means can be moved by means of the respective assigned cam in response to a rotation of the cam shaft.
In the event that the support structure comprises a plurality of second spring elements and accordingly a plurality of first and second holding means for holding the respective second spring elements, the cam shaft can be embodied such that a plurality of cams are embodied on the cam shaft such that the respective second spring elements can in each case be coupled successively to the base support as well as to the support part in response to a rotation of the cam shaft beyond a predetermined range of the angle range of rotation. In this case, the number of the second spring elements, which are in each case coupled to the base support as well as to the support part and which accordingly generate a reset force in response to a movement of the support part, can be increased successively by rotating the cam shaft.
An elastomer torsion spring element, which comprises an inner housing, an outer housing surrounding the inner housing and an elastomer body, which is arranged in a space between the inner housing and the outer housing, for example, can be used as first and/or second spring element of the respective power system of the respective support structures. Said inner housing encompasses at least one contact surface, at which the elastomer body is in contact with the inner housing. Said outer housing encompasses at least one contact surface, at which the elastomer body is in contact with the outer housing, wherein the elastomer body is fixedly connected to the contact surface of the inner housing and to the contact surface of the outer housing and wherein the inner housing and/or the outer housing is arranged so as to be capable of being rotated about an axis of rotation.
In the event that the respective first spring element is embodied in the form of the afore-mentioned elastomer torsion spring element, this elastomer torsion spring element can then be coupled to the base support and to the support part such that the respective movement of the support part causes a rotation of the inner housing and/or of the outer housing about the axis of rotation such that the inner housing is moved relative to the outer housing in response to the rotation and a deformation of the elastomer body is thereby generated, so that the elastomer body generates a reset torque between the outer housing and the inner housing, which is directed opposite to the rotation. Accordingly, in the event that the respective second spring element is embodied in the form of the above-mentioned elastomer torsion spring element, this elastomer torsion spring element can be coupled to the base support and to the support part by means of the respective coupling device such that the respective movement of the support part causes a rotation of the inner housing and/or of the outer housing about the axis of rotation such that the inner housing is moved relative to the outer housing in response to the rotation and a deformation of the elastomer body is thereby generated, so that the elastomer body generates a reset torque between the outer housing and the inner housing, which is directed opposite to the rotation. The reset torque is accompanied by a reset force, which acts on the support part, due to the mentioned coupling between the outer housing or the inner housing, respectively, and the base support or the support part, respectively.
Elastomer torsion spring elements of the aforementioned type have the advantage that they make it possible to realize the respective power system in a particularly compact (space-saving) manner and that they provide for a coupling of the respective spring element to the base support and to the support part, which can be realized by means of particularly simple means. This applies in particular when the respective support part is attached to a bearing shaft, which is supported on the base support such that the support part can be pivoted about a pivot axis. In this case, the respective elastomer torsion spring element can be coupled to the base support and to the support part, for example, such that the outer housing is rigidly connected to the base support and that the inner housing is rigidly connected to the support part or to the bearing shaft. In the alternative, the inner housing can be rigidly connected to the base support and the outer housing can be rigidly connected to the support part or to the bearing shaft. The inner housing of the respective elastomer torsion spring element can thereby be realized in the form of a ring-shaped structure, which can be attached onto the bearing shaft such that the inner housing surrounds the bearing shaft in a ring-shaped manner. In the alternative, the bearing shaft can be realized in the form of a pipe and the elastomer torsion spring element can be installed into the pipe.
Advantageously, the respective elastomer torsion spring element of the afore-mentioned type can be formed such that the contact surface of the inner housing encompasses a non-circular cross section in a sectional plane, which is vertical to the axis of rotation and/or that the contact surface of the outer housing encompasses a non-circular cross section in a sectional plane, which is vertical to the axis of rotation. The mentioned cross sections of the inner housing or of the outer housing, respectively, can be embodied so as to be angular, for example, and can encompass the form of a square or of a rectangle, for example. This has the advantage that the reset torque, which generates such an elastomer torsion spring element when the outer housing is twisted about a certain angle of rotation relative to the inner housing, varies to a relatively high degree with the angle of rotation. Such an elastomer torsion spring element thus makes it possible to generate a relatively large reset torque in response to a predetermined angle of rotation (as compared to the elastomer torsion spring element known from EP 1486142 A1, the inner housing and the outer housing of which in each case encompass contact surfaces, which adjoin the respective elastomer body and the cross section of which encompasses the shape of a circle in a sectional plane, which is vertical to the axis of rotation). The reset torque furthermore displays a linear rise as function of the angle of rotation across a relatively large area of the angle of rotation.
In an alternative of the above-mentioned elastomer torsion spring elements, at least one holding element can be arranged in each case on the respective elastomer torsion spring element, with said holding element being designed
Accordingly, the elastomer body of this elastomer torsion spring element is prestressed when the inner housing of the elastomer torsion spring element is in the respective basic position. Such an elastomer torsion spring is thus able, in response to any small deflection of the support part out of a basic position, to generate a reset force, which acts on the support part and which is always greater than a minimum value (greater than 0). Accordingly, a reset force can be generated, which acts on the support part and which is sufficient to support a relatively heavy person even if the support part is in a basic position. In the case of a power system comprising a plurality of spring elements, different spring elements can also be prestressed to varying degrees, so that they generate different-sized reset forces.
The holding element of the afore-mentioned type can be realized in different ways.
In one embodiment, the holding element includes at least one clamping element, which either encompasses a first section, which is fixedly engaged with the inner housing, and which encompasses a second section, which strikes against a section of the outer housing—when the inner housing is in the predetermined basic position relative to the outer housing—and releases a rotation of the inner housing and of the outer housing in relation to one another about the axis of rotation in that direction of rotation, in which the reset torque increases. Advantageously, this embodiment provides the opportunity for a plurality of elastomer torsion spring elements, the inner housings of which are connected to one another in a torsionally rigid manner, to be prestressed together in a single operating step. This simplifies the assembly of a power system comprising a plurality of elastomer torsion spring elements, which are to be prestressed in a predetermined basic position. In the alternative, the clamping element can also encompass a first section, which is fixedly engaged with the outer housing and can encompass a second section, which strikes against a section of the inner housing—when the inner housing is in the predetermined basic position relative to the outer housing—and releases a rotation of the inner housing and of the outer housing in relation to one another about the axis of rotation in that direction of rotation, in which the reset torque increases.
In a further alternative, the inner housing comprises a recess. The first section of the clamping element is furthermore inserted into this recess in the inner housing in a torsionally rigid manner and the second section of the clamping element strikes against a section of the outer housing when the inner housing is in the predetermined basic position relative to the outer housing. This alternative makes it possible for the elastomer body of an individual elastomer torsion spring element of the afore-mentioned type to be prestressed initially in that the outer housing is twisted relative to the inner housing. After the clamping element has been inserted into the recess in the inner housing as mentioned, the outer housing is held in a basic position such that the prestress of the elastomer body is retained. The elastomer torsion spring element, which is prestressed in such a manner, has the advantage that, together with the clamping element, it forms a modular unit, which (in the prestressed state) can be transported as a whole and can be assembled into a support structure according to the invention.
Further details of the invention and in particular exemplary embodiments of the support structure according to the invention will be specified below in connection with a seat assembly by means of the enclosed drawings.
As is suggested in
The base support 14 furthermore serves as a housing for accommodating mechanical elements, which will be described below, in particular in context with
The back part 20 comprises a backrest 22 and a connecting piece 21, which is embodied as an angle profile, wherein the backrest 22 is attached to a journal of this angle profile and the other journal of this angle profile serves to attach the back part 20 to the support part 16. As is suggested in
The seat 24 is located on a seat support 28, which can be pivoted about a pivot axis in the instant case. The seat support 28 is attached to the support part 16 (as is suggested in
The afore-described arrangement of the support part 16, of the back part 20 and of the seat support 28 on the base support 14 makes it possible for a person sitting on the chair 10 to be able to lean back with the backrest 22 and for the seat support 28 and thus the seat surface 24 to be capable of being pivoted at the same time synchronous to this.
To make it possible for the back part 20 and the seat 24 to be able to assume a stable position even if the back part 20 and the seat 24 are moved relative to the basic position illustrated in
In the case of the support structure 13, the support part 16 accordingly supports the back part 20 and the seat 24 and keeps the back part 20 and the seat 24 in a position, which is a function of the relative position of the support part 16 with reference to the base support 14.
The state illustrated in
The power system 30 according to
In context with the facts illustrated in
The inner housing 43 of each of the spring elements 32, 33′, 33″, and 33″′ encompasses a continuous channel, the cross section of which is embodied such that the bearing shaft 18 can be guided through this channel and each of the spring elements 32, 33′, 33″ and 33″′ can be attached to the bearing shaft 18 such that the respective inner housing 43 of each of the spring elements 32, 33′, 33″ and 33″′ is connected to the bearing shaft 18 in a positive fit and sits on the bearing shaft 18 such that the respective inner housing 43 is connected to the bearing shaft 18 in a torsionally rigid manner.
As is suggested in
The first spring element 32 of the power system 30 is coupled to the base support 14 as well as to the support part 16 in the following manner: a first section of the first spring element 32, that is the inner housing 43 of the first spring element 32, is—as already specified—connected to the bearing shaft 18 in a torsionally rigid manner and is thus rigidly coupled to the bearing shaft 18 and thus also to the support part 16. The inner housing 43 is rotated about the axis of rotation of the bearing shaft 18 in response to a pivoting motion of the support part 16. Furthermore, a second section of the first spring element 32, the outer housing 44 of the first spring element 32, is rigidly connected to the base support 14 (which cannot be seen from
According to an embodiment of the invention, the power system 30 provides the opportunity to bring the second spring elements 33′, 33″ and 33″′ in each case into a state (referred to hereinbelow as “coupled state”), in which the respective spring element 33′, 33″ or 33″′ is coupled to the base support 14 and to the support part 16 and to further bring it into another state (referred to hereinbelow as “uncoupled state”), in which the respective second spring element 33′, 33″ or 33″′ is not coupled to the base support 14 and/or to the support part 16.
For this purpose, the power system 30 comprises a coupling mechanism 34 for coupling the respective second spring element 33′, 33″ or 33″′ to the base support 14 and/or to the support part 16. The coupling mechanism 34 is attached to the base support 14 and can (as will be specified in more detail below) be brought into different states, in which the coupling mechanism 34 interacts either with the respective second spring element 33′, 33″ or 33″′ such that the respective second spring element 33′, 33″ or 33″′ is in the coupled state and is capable in this state to generate a reset force, which acts on the support part 16 or interacts such that the respective spring element 33′, 33″ or 33″′ is in the uncoupled state and is not capable in this state to generate a reset force, which acts on the support part 16.
In the instant example, the coupling mechanism 34 comprises a total of three “coupling devices”, wherein one of these coupling devices is in each case assigned to one of the respective second spring elements 33′, 33″ or 33″′, respectively.
The “coupling device” assigned to the second spring element 33′ comprises:
The first holding means 36′ for holding the outer housing 44 of the second spring element 36′ is embodied in the form of a movable part, which is attached to the base support 14 and which (as will be specified below in more detail) can be brought into a “first” position on the one hand, in which the first holding means 36′ is brought into contact with the outer housing 44 of the second spring element 33′ and holds the outer housing 44 in a predetermined position relative to the base support 14 and, on the other hand, can be brought into a “second” position, in which the first holding means 36′ is not in contact with the outer housing 44 of the second spring element 33′.
It follows from this that the first holding means 36′ is a means for holding the outer housing 44 of the second spring element 33′ so as to be capable of being detached, wherein the outer housing 44 is only held by the first holding means 36′ when the holding means 36′ is in the mentioned first position, and the outer housing 44 is separated (detached) from the first holding means 36′ in the event that the first holding means 36′ is in the second position.
The afore-mentioned “coupling device”, which is assigned to the second spring element 33′, has the characteristic that the outer housing 44 of the second spring element 33′ is connected to the base support 14 when the first holding means 36′ is brought into the mentioned first position and the inner housing 43 of the second spring element 33′ is rigidly connected to the bearing shaft 18 and is thus rigidly connected to the support part 16. In this case, the second spring element 33′ is in the already mentioned coupled state. However, if the first holding means 36′ is brought into the mentioned second position, the outer housing 44 of the second spring element 33′ is not connected to the base support 14. According to this assumption, the first spring element 33′ is in the uncoupled state. In this case, the second spring element 33′ is rotated together with the bearing shaft 18 as a whole in response to a rotation of the bearing shaft 18 about the longitudinal direction thereof. The inner housing 43 of the second spring element 33′ is not twisted relative to the outer housing 44 and the elastomer body 46 of the second spring element 33′ is not deformed. Accordingly, the second spring element 33′ cannot generate a reset force, which acts on the support part 16 and which counteracts this pivoting motion, in response to a pivoting motion of the support part 16, in the event that the first holding means 36′ is in the second position.
Those “coupling devices” of the coupling mechanism 34, which are assigned to the respective second spring elements 33″ and 33″′, are constructed analogous to those coupling devices, which were previously described in context with the second spring element 33′, with reference to their structure and function. Accordingly, the coupling mechanism 34 comprises (analogous to the first holding means 36′) a first holding means 36″ for detachably holding the outer housing 44 of the second spring element 33″ and a first holding means 36″′ for detachably holding the outer housing 44 of the second spring element 33″′. Accordingly, the coupling mechanism 34 furthermore comprises (analogous to the mentioned second holding means for the second spring element 33′) a second holding means for holding the inner housing 43 of the spring element 33′ (realized in the form of the already mentioned positive connection between the inner housing 43 of the second spring element 33″ and the bearing shaft 18) and a second holding means for holding the inner housing 43 of the second spring element 33″′ (realized in the form of the already mentioned positive connection between the inner housing 43 of the second spring element 33″′ and the bearing shaft 18).
As is suggested in
As is furthermore suggested in
The cams 40′-40″′ in
As becomes clear from a comparison with
As specified above, a (total) reset torque acts on the bearing shaft 18 in each case, with said reset torque corresponding to the sum of all of the reset torques generated by those spring elements 32, 33′-33″′, which are in each case in the coupled state and are accordingly coupled to the base support 14 as well as to the support part 16. Due to the fact that only the first spring element 32 is in the coupled state in the state of the power system 30 illustrated in
In the state according to
On its outer side, the inner housing 43 encompasses a contact surface 43a, on which the elastomer body 46 is in contact with the inner housing 43. On its inner side, the outer housing 44 furthermore encompasses a contact surface 44a, on which the elastomer body 46 is in contact with the outer housing 44. The contact surface 43a of the inner housing 43 and the contact surface 44a of the outer housing 44 enclose the axis of rotation 47 in a ring-shaped manner in each case. Accordingly, the elastomer body 46 in the instant example forms a closed ring, which surrounds the axis of rotation 47.
The elastomer body 46 consists of an elastomer, that is, a fixed and elastically deformable material. The elastomer body 46 is embodied such that it is fixedly connected to the contact surface 43a of the inner housing 43 and to the contact surface 44a of the outer housing 44. That is, a displacement of the surfaces of the elastomer body 46 abutting on the contact surfaces 43a and 44a relative to the contact surfaces 43a and 44a does not take place in response to a movement of the inner housing 43 relative to the outer housing (e.g. in response to a rotation of the inner housing 43 or of the outer housing 44 about the axis of rotation 47). The elastomer body 46 can be connected to the inner housing 43 and to the outer housing 44 by means of material engagement or in a form-fit manner on the contact surfaces 43a or 44a, respectively.
An elastomer, which is particularly well-suited for the production of the elastomer body 46, is a rubber, for example, which is not only an elastically deformable and high-tensile material, but which can also be fixedly connected to the contact surfaces 43a and 44a in a simple manner such as, for example, by means of vulcanizing.
The inner housing 43 and the outer housing 44 are made from a solid material such as, for example, steel. The respective contact surfaces 43a and 44a of the inner housing 43 or of the outer housing 44, respectively, which in each case adjoin the elastomer body 46—in a sectional plane, which is perpendicular to the axis of rotation 47—differ from a circular design, at least in sections. Due to this special form, pressure loads, which compensate tensile forces therein, appear in several areas of the elastomer body 46, in response to the rotation of the inner housing 43 about the axis of rotation 47 in relation to the outer housing 44. The elastomer body 46 is thus not loaded in a homogenous manner.
In
After a rotation of the inner housing 43 about the angle of rotation φ about the axis of rotation 47, the elastomer body 46 is deformed and generates a reset torque D between the outer housing 44 and the inner housing 43, which is directed opposite to the rotation and which increases with the angle of rotation φ.
The fact that the distances x2-xl and y2-y2 are reduced in response to a rotation of the inner housing 43 about the angle of rotation φ, is a result of the fact that the cross section of the contact surface 43a or of the contact surface 44a, respectively is not circular (in a cutting surface vertical to the axis of rotation 47). The result of the geometric deviation of the mentioned cross sections of the contact surfaces 43a or 44a, respectively, from a circularity is that, in response to a rotation of the inner housing 43 about the angle of rotation φ, a spatial distribution of the mechanical stress results in the elastomer body 46, which is not rotationally symmetrical to the axis of rotation 47. This is contrary to the spatial distribution of the mechanical stresses in an elastomer torsion spring element according to EP 1486142 A1, which is rotationally symmetrical to the axis of rotation 47 in each case. These differences with reference to the stress distribution lead to considerable differences with reference to the dependencies of the reset torque D as a function of the angle of rotation φ. In particular, these differences cause an elastomer torsion spring element comprising the form illustrated in
In the embodiment illustrated in
The contact surface 44a of the outer housing 44 adjoining the elastomer body 46 has a contour, which is to be considered to be a combination of a rectangle and a circle. More specifically, the contour of the outer housing 44 is comprised of two equal-legged angular segments, which are located opposite one another in pairs and which draw an angle of 90° in the instant example, and of two semi circle segments, which are located opposite to one another in pairs and the ends of which are in each connected to the ends of the mentioned angular segments. By means of a plurality of test series, which were carried out, it was determined that this seemingly “lemon-shaped” contour of the outer housing 44, in combination with the square contour of the inner housing 43, is particularly advantageous for creating an elastomer torsion spring element, the characteristic curve of the reset torque D of which runs linear in virtually all areas of the angle of rotation φ in relation to the angle of rotation φ.
The clamping element 49 is a substantially flat plate, the center area of which is punched such that two flanges 50′, 50″, which are located opposite one another, remain. These flanges are in each case curved inward by 90° (into the figure plane). Straps 52′, 52″, which are also curved inward by 90°, are embodied on an outer area of the clamping element 49.
For assembling the respective clamping element 49 to the second spring element 33′, the flanges 50′, 50″, which are embodied such that the outer areas thereof can be connected to the inner surface of the inner housing 43 in a positive fit, are inserted into the inner housing 43 about a first distance. Then, the clamping element 49 and the inner housing 43, which is connected thereto in a positive fit in radial direction, are twisted counter clockwise about a certain angle (for example) 20° in relation to the outer housing 44.
Subsequently, the clamping element 49 is pushed completely into the channel 43.1 of the inner housing 43 with its flanges 50′, 50″, wherein the straps 52′, 52″ assume a positive connection with the outer surface of the outer housing at the same time. Assembled in this manner, the clamping element 49 maintains the prestress. More specifically, the prestress angle Δ® can no longer be fallen below, because the straps 52′, 52″ strike against the outer surface of the outer housing 44. However, an increase of the rotational displacement (also counter clockwise) between the inner housing 43 and the outer housing 44 is possible. In response to an increase of this rotational displacement, the inner areas of the straps 52′, 52″ slide along the outer surface of the outer housing 44 or are removed therefrom. To prevent a destruction of the second spring element 33′, a maximum angle of rotation (for example 70°) is not to be exceeded between the inner housing 43 and the outer housing 44 in this example. This is so, because the strap 52′ strikes against the outer housing cam 42′ in the case of the maximum angle of rotation φ, thus advantageously preventing a further rotation.
The clamping element 49 can also be used in combination with the spring elements 32, 33″ and 33″′ analogous to the example illustrated in
Accordingly, each of the second spring elements 33′, 33″ and 33″′ of the power system 30 generates a reset torque, which acts on the bearing shaft 18 in each case, in response to a rotation of the bearing shaft 18, with said reset torque being greater or equal to a predetermined minimum value (different from zero), provided that the respective second spring element 33′, 33″ or 33″′, respectively, is in the coupled state.
The clamping elements 54′-54″″ are plate-like elements, the inner areas of which are punched in a rectangular manner. The contour of the punch is hereby adapted in a positive fit to the outer contour of the (square) bearing shaft 18. Curvatures 55′-55″″, which in each case include a through hole, are integrally molded on the outer areas of the clamping elements 54′-54″″.
In response to the assembly of the power system 30, the bearing shaft 18 and the inner housing 32 of the first spring element 32 are connected to one another in a positive fit in radial direction. A first clamping element 54′ is subsequently attached onto the bearing shaft 18 across its punch, so that a positive connection in radial direction is also established between the bearing shaft 18 and the clamping element 54′. The second spring element 33′ is subsequently attached to the bearing shaft 18. Following this step, a further clamping element 54″ is attached, etc. After all three second spring elements 33′-33″′ have been attached onto the bearing shaft 18 with clamping elements 54′-54″′, which have been placed therebetween in each case, the last clamping element 54″″ is finally attached on the front side.
Subsequently, the second spring elements 33′-33″′ are prestressed either individually or at the same time, in that their outer housings, for example, are rotated clockwise about the longitudinal direction of the bearing shaft 18 in response to a radially fixed bearing shaft 18. This rotation takes place up to an angle or rotation, at which pins 56′, 56″ can be inserted through the respective holes of the curvatures 55′-55″″. After the pins 56′, 56″ have been inserted through these holes, the introduction of force for turning the outer housings is ended. In this state, the outer housings 44 of the individual second spring elements 33′-33″′ remain in this position, because the respective outer surfaces of the outer housings 44 now strike against a peripheral section of the pins 56′, 56″. It is thus now no longer possible for the respective outer housings 44 to be turned back into the initial state.
An advantage of the arrangement and of the embodiment of the clamping elements 54′-54″″ is that, contrary to the examples shown in
A further advantage of the example shown in
In addition, the assembly time is markedly shortened. A further advantage lies in the much simpler and less time-intensive production of the individual clamping element 54′-54″″. They can only be produced in a cost-efficient manner by means of punches.
The clamping device 58 further includes a rod 62, which is connected vertically between two lever arms of a lever 64. The lever arms are pivotably articulated via clamping device bearings 66′, 66″. The lever 64 can be deflected back and forth at its lower end via a drive 68. In response to a deflection of the lower section of the lever 64 in a direction out of the figure plane of
As can be seen particularly well in
Starting at a second stage of the deflection of the rod 62 in the direction of the arrow A, a further surface area of the rod 62 engages with the outer surface of the outer housing of a further spring element, in this example with the outer housing 44 of the second spring element 33″. During the deflection of the rod 62 between the first stage and the second stage, the outer surface of the outer housing 44 of the second spring element 33″′, which was previously brought into engagement, is also rotated or twisted, respectively. In a third stage of the deflection of the rod 62 in the direction of the arrow A, an area of the outer surface of the outer housing of a further spring element, in this example the outer housing 44 of the second spring element 33′, is engaged. During the deflection of the rod 62 between the second stage and the third stage, the second spring elements 33″′ and 33″ are deflected or twisted, respectively. In a fourth stage of the deflection of the rod 62, all spring elements 33′-33″′ are now deflected or twisted, respectively, parallel to one another such that the pins 56′, 56″, which are also illustrated in
This prestress cannot be fallen below, but the outer housings 44 of the individual second spring elements 33′-33″′ can be further rotated relative to the corresponding inner housings 43 in a direction of rotation such that the reset torque generated by the respective second spring element 33′-33″′ is increased as the angle of rotation increases, until the outer housing cams 42′-42″′, which are integrally molded on the respective outer housing 44, strike against the pin 56′. In this state, the second spring elements 33′-33″′ have reached their maximally permissible angle of rotation and in each case provide for the largest possible reset torque.
The clamping device 58 illustrated in
The support structure 13a according to
The support structure 13a comprises a power system 30a, which comprises two first spring elements 32a and second spring elements 33′, 33″ and 33″′. The spring elements 32a, 33′, 33″ and 33″′ are in each case designed as elastomer torsion spring element and are identical with the spring element 33′ according to
As is suggested in
The second spring elements 33′, 33″ and 33″′ of the power system 33a correspond to the second spring elements 33′, 33″ and 33″′ of the power system 30 from a functional point of view. The support structure 13a also comprises the same coupling mechanism 34 and the actuating means 38 for controlling the coupling mechanism such that the respective second sprig elements 33′, 33″ and 3″′ can be brought either into the coupled state (in which the respective second spring element 33′, 33″ and 33″′ is coupled to the base support 14 as well as to the support part 16 via the coupling mechanism 34) or into the uncoupled state (in which the respective spring element 33′, 33″ and 33″′ is not coupled to the base support 14 and/or to the support part 16).
An important feature of the support structure 13a is to be seen in that the support part 16 and the two ends of the bearing shaft 18 are always coupled to the base support 14 via the elastomer bodies 46 of the two first spring elements 32a, wherein the elastomer bodies 46 can accommodate a load, which acts radially on the bearing shaft 18. In the case of the support structure 13a, the bearing shaft 18 accordingly does not require a separate swivel, which supports the bearing shaft 18 rotatably on the base support 14. In the instant case, the first spring elements 32a serve as bearing for the bearing shaft 18, in particular when none of the second spring elements 33′-33″′ is switched into the coupled state. In the event that one of the second spring elements 33′-33″′ is in the coupled state, this spring element also serves as support for the bearing shaft 18 with reference to the base support 14.
The spring elements 32a thus carry out a double function: as means for generating a reset force/torque acting on the support part 16 and as bearing for the support of the bearing shaft 18. An advantage of this arrangement lies in that separate swivels are not necessary through this. Costs are thus reduced. In addition, this arrangement saves space. A further advantage lies in that forces appearing radially to the bearing shaft 18 can be accommodated by means of the elastomer body 46 between the inner housing 43 and the outer housing 44 of the first spring element 32a. This arrangement thus achieves an advantageous elastic coupling between the base support 14 and the support part 16, which increases the seating comfort.
While the invention has been described and illustrated with reference to certain particular embodiments thereof, those skilled in the art will appreciate that various adaptations, changes, modifications, substitutions, deletions, or additions of procedures and protocols may be made without departing from the spirit and scope of the invention. It is intended, therefore, that the invention be defined by the scope of the claims that follow and that such claims be interpreted as broadly as is reasonable.
| Number | Date | Country | Kind |
|---|---|---|---|
| EP 10405014.1 | Jan 2010 | EP | regional |
