Apparatus comprising a stationary frame and a load carrying linkage construction

Abstract

An apparatus (1) comprising a stationary frame (2) and a load (4) carrying linkage construction (3) which is movable with respect to the stationary frame (2), wherein the linkage construction (3) and the stationary frame (2) are connected to each other with at least a first spring (5) and at least a second spring (6), wherein opposite ends (5', 5' ') of the first spring (5) are directly connected to the stationary frame (2) and the linkage construction (3) so as to provide positive stiffness in moving the linkage construction (3), and the second spring (6) is embedded in the linkage construction (3) so as to provide negative stiffness in moving the linkage construction (3).

Description

[0001] Apparatus comprising a stationary frame and a load carrying linkage construction

[0002] The invention relates to an apparatus comprising a stationary frame and a load carrying linkage construction which is movable with respect to the stationary frame. The invention further relates to an apparatus comprising a stationary frame and a load carrying movable frame which is movable with respect to the stationary frame.

[0003] US2023 / 408027 teaches an apparatus comprising a wall frame and an application frame. The application frame is movable with respect to the wall frame. The apparatus includes a first spring system and a second spring system, which two spring systems are each coupled with the wall frame and the application frame to apply forces on the application frame. The first spring system has its opposite ends connected to the wall frame and the application frame respectively. The second spring system is at a first end connected to the wall frame and the second spring system is at a second end distant from the first end connected to an adjusting device which is coupled with the application frame. The adjusting device is arranged to vary an extension of the second spring system when the application frame moves with respect to the wall frame. The adjusting device includes a single trajectory profile element, and only a first arm and a second arm that are connected to each other at a first hinge. An end of the first arm distant from the first hinge is with a second hinge connected to the application frame. An end of the second arm distant from the first hinge is with a third hinge connected to the second spring system. The first hinge that joins the first arm and the second arm is movably connected to and guided by the single trajectory profile element.EP-2 223 004 Bl teaches an apparatus for exerting a force on a load, comprising at least a first spring system and a second spring system, which two spring systems are coupled with the load and produce forces that are applied to the load, wherein an adjusting device is provided coupled with the load, which is equipped with at least one coupling with which the first spring system and / or the second spring system are / is coupled, and which adjusting device is designed for moving the coupling subject to an adjustment of the load, wherein the first spring system has a linear spring characteristic and is coupled with the load, and wherein the second spring system is coupled with the coupling at a side of the coupling removed from the load, and wherein the coupling is designed for adjusting the second spring system subject to a predetermined spring characteristic of the second spring system such that, at the side of the load, the combination of the coupling with the second spring system possesses a force path diagram having a linear characteristic.

[0004] An object of the invention is to simplify the apparatus that is known from the prior art. Another object of the invention is to provide an apparatus which is capable to balance a load using linear springs only, without need of pretensioning.

[0005] The apparatus according to the invention has the features of one or more of the appended claims.

[0006] A first embodiment of the apparatus according to the invention comprises a stationary frame and a load carrying movable frame which is movable with respect to the stationary frame. The movable frame and the stationary frame are connected to each other with at least a first spring and at least a second spring, wherein opposite ends of the first spring are directly connected to the stationary frame and the movable frame so as to provide positive stiffness in moving the movable frame. Thesecond spring is indirectly connected through an intermediate linkage construction to the stationary frame and the movable frame so as to provide negative stiffness in moving the movable frame. The linkage construction comprises a first leg and a second leg that have a j oint in common that connects said legs with the stationary frame. The first leg and second leg enclose an angle at the j oint, wherein distant from the joint there are two base j oints. A first base joint is provided with a first link connected to the movable frame, wherein opposite ends of said first link are rotatably connected with respectively the first base joint and with the movable frame. A second base j oint is rotatably connected to a second link on a first end of the second link, whereas a second end of the second link that is distant from the first end is guided along the movable frame, and wherein opposite ends of the second spring connect the stationary frame to the second end of the second link.

[0007] A second embodiment of the apparatus according to the invention apparatus comprises a stationary frame and a load carrying linkage construction which is movable with respect to the stationary frame. The linkage construction and the stationary frame are connected to each other with at least a first spring and at least a second spring, wherein opposite ends of the first spring are directly connected to the stationary frame and the linkage construction so as to provide positive stiffness in moving the linkage construction. The second spring is embedded in the linkage construction so as to provide negative stiffness in moving the linkage construction. The linkage construction comprises a first leg and a second leg that have a j oint in common that connects said legs with the stationary frame, and which first leg and second leg enclose an angle at the j oint. Distant from the joint there are two base j oints, a first base j oint being provided with a first link slidably connected to the stationary frame, whereinopposite ends of said first link are rotatably connected with respectively the first base joint and with the stationary frame. Further there is a second base joint which is rotatably connected to a second link on a first end of the second link, whereas a second end of the second link that is distant from the first end is slidably connected to the stationary frame, and wherein opposite ends of the second spring connect the stationary frame to the second end of the second link.

[0008] In both embodiments it is preferable that a distance between the opposite ends of the first spring is adjustable to accommodate the apparatus to different loads.

[0009] It may also be beneficial that a distance between the opposite ends of the second spring is adjustable so as to control the amount of negative stiffness that the second spring provides to the apparatus.

[0010] It is further remarked that preferably the angle between the first leg and the second leg is 90 °.

[0011] Preferably in the first embodiment the stationary frame and the movable frame are slidably connected to each other.

[0012] Suitably the stationary frame and the movable frame are connected through guide rails.

[0013] In a preferred embodiment the second end of the second link is provided with a guide wheel which is movably pressed against the movable frame.

[0014] The accompanying drawing, which is incorporated into and forms a part of the specif ication, illustrates one or more embodiments of the present invention and, together with the description, serves to explain the principles of theinvention. The drawing is only for the purpose of illustrating one or more embodiments of the invention and is not to be construed as limiting the invention.

[0015] In the drawing:

[0016] Figures 1A-1F depict a first embodiment of an apparatus according to the invention;

[0017] Figures 2A-2F depict a second embodiment of an apparatus according to the invention;

[0018] Figures 3A-3F depict a third embodiment of an apparatus according to the invention;

[0019] Figures 4A-4F depict a fourth embodiment of an apparatus according to the invention;

[0020] Figures 5A-5F depict a fifth embodiment of an apparatus according to the invention; and

[0021] Figures 6A-6B depict a sixth embodiment of an apparatus according to the invention.

[0022] Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts.

[0023] Turning now to the first embodiment as shown in figures 1A-1F and variations of this first embodiment in respectively figures 3A-3F, figures 4A-4F, and figures 5A-5D, it shows a stationary frame 2 and a load carrying movable frame 15 which is movable with respect to the stationary frame 2. The movable frame 15 and the stationary frame 2 are connected to each other with at least a first spring 5 and at least a second spring 6, wherein opposite ends 5', 5' ' of the first spring 5 are directly connected to the stationary frame 2 and the movable frame 15 so as to provide positive stiffness in moving the movable frame 15.

[0024] The second spring 6 is indirectly connected through an intermediate linkage construction 3 to the stationary frame 2and the movable frame 15 so as to provide negative stiffness in moving the movable frame 15.

[0025] The parts of the construction 3 providing positive stiffness and negative stiffness are indicated in figures 1B, 3B, 4B and 6B.

[0026] The intermediate linkage construction 3 comprises a first leg 7 and a second leg 8 that have a joint 10 in common that connects said legs 7, 8 with the stationary frame 2, and which first leg 7 and second leg 8 enclose an angle of preferably 90 ° at the joint 10.

[0027] Distant from the joint 10 the legs 7, 8 are provided with two base j oints 11, 12, a first base j oint 11 being provided with a first link 13 connected to the movable frame 15, wherein opposite ends 13', 13' ' of said first link 13 are rotatably connected with respectively the first base joint 11 and with the movable frame 15. Further a second base j oint 12 is rotatably connected to a second link 14 on a first end 14' of the second link 14, whereas a second end 14 ' ' of the second link 14 that is distant from the first end 14' is guided along the movable frame 15. Opposite ends 6', 6' ' of the second spring 6 connect the stationary frame 2 to the second end 14' ' of the second link 14.

[0028] The stationary frame 2 and the movable frame 15 are slidably connected to each other, preferably through guide rails 16. It is also preferred that the second end 14 ' ' of the second link 14 is provided with a guide wheel 17 which is movably pressed against the movable frame 15.

[0029] Figures 1C-1F illustrate the downward movement of the movable frame 15 with respect to the stationary frame 2, and the varying extension of the springs 5, 6 with varying position of the movable frame 15.Figures 3C-3F show a variation of the first embodiment and illustrate the downward movement of the movable frame 15 with respect to the stationary frame 2, and the varying extension of the springs 5, 6 with varying position of the movable frame 15.

[0030] Figures 4C-4F and figures 5A-5F show further variations of the first embodiment and illustrate the downward movement of the movable frame 15 with respect to the stationary frame 2, and the varying extension of the springs 5, 6 with varying position of the movable frame 15.

[0031] In figures 5A-5F it is further shown that a distance between the opposite ends 5', 5' ’ of the first spring (5) may be made adjustable by application of a slide 17 which provides for the possibility to adjust the position of one spring end 5' which is thus made slidable along the stationary frame 2.

[0032] Still a further variation to the embodiments discussed above is shown in figures 6A and 6B. In these figures a distance between the opposite ends 6', 6' ' of the second spring 6 is adjustable with a slide 19 which is movable along the movable frame 15. This provides for the possibility to adjust the amount of negative stiffness. In this embodiment it is also shown that a third spring 18 can counteract the operation of the second spring 6, which enables that the negative stiffness mechanism comprising the second spring 6 as depicted in figures 6A / 6B can be adjusted energy neutral.

[0033] It is to be stressed that all the features that are discussed with reference to particular embodiments as depicted in the figures 1A-1F, 3A-3F, 4A-4F. 5A-5F, and 6A-6F can be applied independently from each other but definitely also j ointly. Therefore mentioning a particular feature with reference to aspecific embodiment does not imply that such feature can only be applied with the other features shown in such a particular embodiment. Any such feature can also be applied generally independent but also in combination with other features shown in relation to other embodiments. The EPO jurisprudence with respect to intermediate generalization does therefore explicitly not apply to the disclosure of the respective embodiments provided herein. Not to mention the fact that such EPO jurisprudence is not in accordance with how a humanly skilled person would read and understand the disclosure provided by this specification, as opposed to the artificial skilled person as brought to life in the EPO jurisprudence.

[0034] With reference now to figure 2A it shows yet another embodiment of the apparatus 1 according to the invention, which apparatus comprises a stationary frame 2 and a load 4 carrying linkage construction 3 which is movable with respect to the stationary frame 2. The linkage construction 3 and the stationary frame 2 are connected to each other with at least a first spring 5 and at least a second spring 6, wherein opposite ends 5', 5' ' of the first spring 5 are directly connected to the stationary frame 2 and the linkage construction 3 so as to provide positive stiffness in moving the linkage construction 3.

[0035] The second spring 6 is embedded in the linkage construction 3 so as to provide negative stiffness in moving the linkage construction 3. The parts of the construction 3 providing positive stiffness and negative stiffness are indicated in figure IB.

[0036] The linkage construction 3 comprises a first leg 7 and a second leg 8 that have a joint 10 in common that connects said legs 7, 8 with the stationary frame 2. The first leg 7 and second leg 8 enclose an angle of preferably 90 ° at the joint10, wherein distant from the j oint 10 the legs 7, 8 are provided with two base joints 11, 12.

[0037] A first base j oint 11 is provided with a first link 13 slidably connected to the stationary frame 2, wherein opposite ends 13', 13' ' of said first link 13 are rotatably connected with respectively the first base joint 11 and with the stationary frame 2, and a second base joint 12 is rotatably connected to a second link 14 on a first end 14 ' of the second link 14, whereas a second end 14' ' of the second link 14 that is distant from the first end 14 ' is slidably connected to the stationary frame 2. Opposite ends 6', 6' ' of the second spring 6 connect the stationary frame 2 to the second end 14 ' ' of the second link 14.

[0038] Figures 2C-2F illustrate the movement of the construction 3 and the springs 5, 6 with varying position of the load 4.

[0039] Although the invention has been discussed in the foregoing with reference to exemplary embodiments of the invention, the invention is not restricted to these particular embodiments which can be varied in many ways without departing from the invention. The discussed exemplary embodiments shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiments are merely intended to explain the wording of the appended claims without intent to limit the claim to these exemplary embodiments. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using these exemplary embodiments.

[0040] Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications andequivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference. Unless specifically stated as being "essential" above, none of the various components or the interrelationship thereof are essential to the operation of the invention. Rather, desirable results can be achieved by substituting various components and / or reconfiguration of their relationships with one another.

Claims

CLAIMS1. An apparatus (1) comprising a stationary frame (2) and a load carrying movable frame (15) which is movable with respect to the stationary frame (2), wherein the movable frame (15) and the stationary frame (2) are connected to each other with at least a first spring (5) and at least a second spring ( 6), wherein opposite ends (5', 5' ' ) of the first spring (5) are directly connected to the stationary frame (2) and the movable frame (15) so as to provide positive stiffness in moving the movable frame (15), and the second spring ( 6) is indirectly connected through an intermediate linkage construction (3) to the stationary frame (2) and the movable frame (15) so as to provide negative stiffness in moving the movable frame (15), characterized in that the linkage construction (3) comprises a first leg (7) and a second leg (8) that have a joint (10) in common that connects said legs (7, 8) with the stationary frame (2), and which first leg (7) and second leg (8) enclose an angle at the joint (10), wherein distant from the joint (10) there are two base joints (11, 12), a first base j oint (11) being provided with a first link (13) connected to the movable frame (15), wherein opposite ends (13', 13' ' ) of said first link (13) are rotatably connected with respectively the first base joint (11) and with the movable frame (15), and a second base joint (12 ) being rotatably connected to a second link (14) on a first end (14' ) of the second link (14), whereas a second end (14 ' ' ) of the second link (14) that is distant from the first end (14' ) is guided along the movable frame (15), and wherein opposite ends ( 6', 6' ' ) of the second spring ( 6) connect the stationary frame (2) to the second end (14' ' ) of the second link (14).

2. An apparatus (1) comprising a stationary frame (2) and a load (4 ) carrying linkage construction (3) which is movable with respect to the stationary frame (2), wherein the linkage construction (3) and the stationary frame (2) areconnected to each other with at least a first spring ( 5 ) and at least a second spring ( 6 ), wherein opposite ends ( 5 ', 5 ' ' ) of the first spring ( 5 ) are directly connected to the stationary frame ( 2 ) and the linkage construction ( 3 ) so as to provide positive stiffness in moving the linkage construction ( 3 ), and the second spring ( 6 ) is embedded in the linkage construction ( 3 ) so as to provide negative stiffness in moving the linkage construction ( 3 ), characterized in that the linkage construction ( 3 ) comprises a first leg ( 7 ) and a second leg ( 8 ) that have a joint ( 10 ) in common that connects said legs ( 7, 8 ) with the stationary frame ( 2 ), and which first leg ( 7 ) and second leg ( 8 ) enclose an angle at the joint ( 10 ), wherein distant from the joint ( 10 ) there are two base joints ( 11, 12 ), a first base joint ( 11 ) being provided with a first link ( 13 ) slidably connected to the stationary frame ( 2 ), wherein opposite ends ( 13 ', 13 ' ' ) of said first link ( 13 ) are rotatably connected with respectively the first base joint ( 11 ) and with the stationary frame ( 2 ), and a second base joint ( 12 ) is rotatably connected to a second link ( 14 ) on a first end ( 14 ' ) of the second link ( 14 ), whereas a second end ( 14 ' ' ) of the second link ( 14 ) that is distant from the first end ( 14 ' ) is slidably connected to the stationary frame ( 2 ), and wherein opposite ends ( 6 ', 6 ' ' ) of the second spring ( 6 ) connect the stationary frame ( 2 ) to the second end ( 14 ' ' ) of the second link ( 14 ).

3. The apparatus according to claim 1 or claim 2, characterized in that the angle enclosed by the first leg ( 7 ) and the second leg ( 8 ) is 90 °.

4. The apparatus of claim 1, 2 or 3, characterized in that a distance between the opposite ends ( 5 ', 5 ' ' ) of the first spring ( 5 ) is adj ustable.

5. The apparatus of claim 4, characterized in that one of the ends of the first spring ( 5 ) is connected to a slide ( 17 ) which is slidable along the stationary frame ( 2 ).

6. The apparatus of any one of claims 1-5, characterized in that a distance between the opposite ends ( 6', 6' ' ) of the second spring ( 6) is adjustable.

7. The apparatus of claim 6, characterized in that one of the ends of the second spring ( 6) is connected to a slide (19) which is slidable along the movable frame (15).

8. The apparatus of claim 7, characterized in that the second spring ( 6) is loadable with a third spring (18) counteracting the operation of the second spring ( 6).

9. The apparatus according to any one of claims 1, and 3-8, characterized in that the stationary frame (2) and the movable frame (15) are slidably connected to each other.

10. The apparatus according to any one of claims 1, and 3-9, characterized in that the stationary frame (2) and the movable frame (15) are connected through guide rails (16).

11. The apparatus according to any one of claims 1, and 3-10, characterized in that the second end (14' ' ) of the second link (14) is provided with a guide wheel (17) which is movably pressed against the movable frame (15).

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