Foldable standing-base mechanism

Abstract

The invention relates to a standing-base mechanism for objects (12) that can be positioned upright, comprising: a support module (10), which can be attached to the lower end of the object (12) and comprises a plurality of support feet (26) which are arranged in a star-shape and can be pivoted between a support position and a folded-up neutral position; and an actuation device (14), which can be attached further up on the object, for moving the support feet (26) from the neutral position into the support position; characterised in that the support feet (26) are resiliently preloaded into the neutral position and, when they are moved into the support position by means of the actuating device (14), are held in the support position by a catch member, and in that the catch member is designed to yield under excess load and to release the support feet.

Description

[0001] FOLDABLE STAND DEVICE

[0002] The invention relates to a stand device for upright objects, with a support module to be attached to the lower end of the object, which has a plurality of support feet arranged in a star shape, which can be pivoted between a support position and a folded-up rest position, and with an actuating device to be attached further up on the object for transferring the support feet from the rest position to the support position.

[0003] The object to be set up can be, for example, a walking stick or crutch. A crutch with a base device of the above-mentioned type is known from DE 20 2016 006 179 Ul.

[0004] The object of the invention is to create a stand device that is easier to handle. This object is achieved according to the invention in that the support feet are elastically preloaded into the rest position and, once they have been transferred into the support position by the actuating device, are held in the support position by a locking member. The locking member is designed to yield under overload and release the support feet.

[0005] According to the invention, the actuating device is only required to move the support feet from the rest position to the down support position, while the reverse process—i.e., moving the support feet from the support position to the rest position—is triggered by the user exerting a downward force on the object. In addition to the weight of the object, the additional force exerted by hand then acts on the support feet, causing the locking mechanism to yield and release the support feet, allowing them to return automatically to the rest position due to the elastic preload.

[0006] This solution has the advantage that the user, when they want to fold the support legs back in, does not have to operate the actuating device again, but simply needs to apply slightly greater pressure to the object (walking stick or crutch). Another advantage is that the mechanical connection between the actuating device and the support module can be formed by a simple pull cable, since the force only needs to be transmitted in one direction. If the crutch is height-adjustable, this also offers the advantage that the length of the pull cable can be easily adapted to the respective length of the crutch by winding an unused section of the pull cable onto a spool.

[0007] In the following, an embodiment example is explained in more detail using the drawing.

[0008] Shown are: Fig. 1 the stand device according to the invention in the rest position;

[0009] Fig. 2 the stand device in the support position;

[0010] Fig. 3 is a section through a support module, which forms an essential part of the stand device, in a rest position;

[0011] Fig. 4 shows a section through the support module in a section plane rotated compared to Fig. 3;

[0012] Fig. 5 is a section in the same section plane as in Fig. 3, but for an Ab support position of the Ab support module;

[0013] Fig. 6 shows a section through the support module in the support position, in the same section plane as in Fig. 4; and

[0014] Fig. 7 shows a section through an operating device belonging to the stand device.

[0015] The stand device shown in Fig. 1 comprises a support module 10 attached to the lower end of an object 12 to be supported. In this example, the object to be supported is a forearm crutch. The stand device also includes an operating device 14, which is attached to the object 12 in a slightly higher position, below a handle 16 of the crutch, and is connected to the support module 10 via a pull cable 18.

[0016] The support module 10 has a housing 20 that is rigidly attached to the lower end of a tube 22 of the crutch. A rubber buffer 24 attached to the lower end of the tube 22 projects downward from the housing 20. Four support feet 26 are pivotally mounted in the housing 20. The bearing points of the support feet 26 are distributed at equal angular intervals around the circumference of the housing 20. Fig. 1 shows the support feet 26 in a rest position in which they are folded upwards onto the tube 22. In this position, the user can use the crutch normally as a walking aid without the stand device being a hindrance.

[0017] The operating device 14 has a handle 28, which is guided vertically on the tube 22 of the crutch. If the user wishes to place the object 12 down, they pull the handle 28 upwards with their hand, exerting tension on the traction cable 18. This moves the support feet 26 into the support position shown in Fig. 2, in which they project in a star shape from the housing 20 and extend diagonally downwards to the ground. The crutch is thus held firmly in a vertical position, in which the rubber buffer 24 is slightly spaced from the ground, so that the weight of the crutch is borne solely by the four support feet 26.

[0018] Fig. 3 shows an axial section through the housing 20 and through two of the four support feet 26, which are in the rest position according to Fig. 1.

[0019] The housing 20 has a base part 30, an upper part 32, and a fastening ring 34 for fastening the housing 20 to the tube 22 of the crutch (not shown in Fig. 3). When the support module 10 is fastened to the tube of the crutch, the tube 22 runs through a channel 36 formed in the housing 20. The lower part of the channel 36 is formed by a cylindrical sleeve 38, on which an armature 40 is guided for vertical movement. A spring 42 is supported on the upper wall of the upper part 32 and elastically biases the armature 40 downward. Held in the lower part of the armature 40 are four bearing pins 44, each forming a pivot bearing for one of the support feet 26. Four retaining pins 46 are held in the base part 30 of the housing 20 such that they each extend through a guide slot 48 formed in one of the support feet 26. In the embodiment shown in Fig.In the state shown in Figure 3, the bearing pins 44 are pressed downward by the spring 42, so that they tend to pull the support feet 26 downward. In doing so, the retaining pins 46 each slide onto a wall of the associated guide slot 48 and exert an upward force on the support foot. Due to a radial offset between the bearing pins 44 and the retaining pins 46, a torque is generated that tends to hold the support foot in the rest position, in which it is folded against the tube of the walking stick.

[0020] The pull cable 18 is connected to the armature 40 inside the housing 20. Therefore, when the user pulls on the pull cable 18, the armature 40 is pulled upward against the force of the spring 42. Accordingly, the support feet 26 also tend to move upward, with one wall of their guide slot 48 running into the retaining pin 46. Thus, the force couple formed at the bearing pins 44 and retaining pins 46 is reversed, and a torque is generated that tends to pivot the support feet 26 outward.

[0021] A part of the armature 40 lying within the spring 42 forms an inner cone 50, against which a spring arm of locking members 52, only partially visible in Fig. 3, rests.

[0022] In Fig. 4, the section plane is rotated so that the locking elements 52 are more clearly visible. The locking elements are held rigidly by their upper end in the upper wall of the upper part 32, and their spring arms are spread downwards from the sleeve 38. At the lower end, each spring arm forms a horizontal shoulder and a knee 54 that rests against the inner surface of the cone 50. When the armature 40 is pulled upwards, the locking elements 52 are elastically deflected inwards, so that their spring arms pivot against the sleeve 38. The cone 50 of the armature 40 merges into a horizontal support wall 56 at the lower end. When the anchor 40 is pulled further upward and the underside of the support wall 56 reaches the height of the knee 54, the locking members 52 spring back to their original position so that their horizontal shoulders rest against the underside of the support wall 56, as shown in Fig. 6. In this way, the anchor 40 is locked in the raised position. Fig.Figure 5 shows a section corresponding to Figure 3 of the support module in the support position. The anchor 40 is locked in the raised position and has compressed the spring 42. By raising the axle pins 44 while the bearings of the retaining pins 46 remain unchanged, the support feet 26 were pivoted downward. The guide slots 48 allow compensation for the changes in length that arise because the axle pins 44 only move vertically and maintain their radial position. The weight of the walking stick presses the upper ends of the support feet 26 against the ground, and this creates a torque that tends to pivot the support foot around the retaining pin 46 and pull the bearing pin 44 and thus the anchor 40 downwards. This is prevented, however, by the locking of the anchor 40. Figure 6 also shows the support feet 26 in the support position.The upper ends of the support feet enter the interior of the housing 20 through openings 58, where they are mounted on the bearing pins 44 of the armature 40.

[0023] If the support feet 26 are to be returned to the rest position, the user presses on the walking aid with their hand, increasing the torque acting on the support feet 26. The support wall 56 of the armature then exerts a downward force on the horizontal shoulders of the locking elements 52, while the radially inner ends of the locking elements remain fixed to the upper part 32 of the housing. This creates a bending moment that tends to pivot the locking elements back against the sleeve 38. The knees 54 of the locking elements move radially inward. If the force is large enough, the knees 54 pass the inner edge of the support wall 56, and the armature 40 slides off the horizontal shoulders of the locking elements 52 and moves downward again under the force of the spring 42. The support feet 26 are thereby pivoted back into the rest position.

[0024] Fig. 7 shows a cross-sectional view of the operating device 14. The handle 28 is formed by an L-shaped tube, the longer vertical leg of which is slidably guided in a clamp 60 rigidly mounted on the tube 22 of the crutch. Fig. 7 shows a vertical shaft 62 of the clamp, through which the tube 22 passes when mounted.

[0025] A chamber inside the clamp 60 contains a spool 64 onto which an upper end section of the traction cable 18 is wound. The traction cable drawn from the spool 64 enters the interior of the tubular handle through an opening and exits the handle at the lower end. At the exit point, the traction cable is clamped by means of a clamping body 66. When the handle 28 is pulled upward, a pull is therefore triggered on the traction cable 18 in order to pull the armature 40 of the support module 10 upward. Since the armature is then held in the raised position by the locking elements 52, slack forms in the section of the traction cable between the clamping body 66 and the spool 64. However, the spool 64 is pretensioned in the direction of rotation by a spring 68 such that the traction cable is wound up and the slack is thus eliminated. The tension exerted by the spring 68 on the pull cable 18 holds the handle 28 in the raised position.Only when the user presses with his hand on the handle 16 of the walking support (Fig. 1) and thus exerts such a large torque on the support feet 26 that the locking is released, the anchor 40, under the action of the spring 42, pulls the pull cable 18 and thus also the handle 28 downwards again, whereby the pull cable is pulled off the spool 64 against the force of the spring 68 until the starting position according to Fig. 1 is reached again.

[0026] If the object 12 is an object adjustable in length, the length of the pull cable 18 can be easily adapted to the changed length of the object by temporarily releasing the clamp on the clamp body 66 so that the coil 64 can effect the necessary length compensation.

Claims

PATENT CLAIMS 1. Stand device for upright objects (12), with a support module (10) to be attached to the lower end of the object (12), which has a plurality of support feet (26) arranged in a star shape and can be pivoted between a support position and a folded-up rest position, and with an actuating device (14) to be attached further up on the object for transferring the support feet (26) from the rest position into the support position, characterized in that the support feet (26) are elastically pretensioned into the rest position and, when they have been transferred into the support position by means of the actuating device (14), are held in the support position by a locking member (52), and in that the locking member (52) is designed to give way under overload and release the support feet.

2. Stand device according to claim 1, in which the support module (10) has an armature (40) which is vertically movable in a housing (20) and connected to the actuating device (14), and in which each support foot (26) is mounted on a bearing pin (44) which is fixed with respect to the armature (40) and a holding pin (46) which is fixed with respect to the housing (20), wherein the bearing pin (44) and the associated holding pin (46) are offset from one another in the radial direction and at least one of them is received in a slotted guide (48) of the support foot (26).

3. Stand device according to claim 2, wherein the armature (40) is elastically biased downwards by a spring (42) and can be pulled into a raised position by means of the actuating device (14), wherein the armature has a contour (50) running obliquely to the vertical, which causes an elastic deflection of the locking member (52) when the armature is pulled up until it engages a support wall (56) of the armature.

4. Stand device according to claim 3, wherein the locking member (52) has a spring arm which is anchored at its upper end to the housing (20) and extends radially outwards downwards and has a shoulder at the lower end which, depending on the vertical position of the armature (40), rests against the contour (50) of the armature (40) or locks onto the support wall (56).

5. Stand device according to claim 4, in which a plurality of locking members (52) are distributed over the circumference of the housing (20).

6. Stand device according to one of the preceding claims, in which the actuating device (14) is connected to the support module (10) by a pull cable (18).

7. Stand device according to claims 3 and 6, wherein the traction cable (18) engages the anchor (40).

8. Stand device according to claim 7, wherein the actuating device (14) has a clamp (60) which can be fastened to the object (12) and a handle (28) which is guided axially movably in the clamp (60) and is connected to the pull cable (18).

9. Stand device according to claim 8, wherein the handle (28) has a leg extending vertically through the clamp (60) and having a clamping body (66) at its lower end for clamping the traction cable (18), and wherein the clamp (60) carries a spring-loaded spool (64) onto which an upper end portion of the traction cable (18) can be wound.

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