Stroke and adjustment device, particularly for adjusting the height of tables and the like

Abstract

 A stroke end adjustment device, particularly for adjusting the height of tables and the like, which is meant to be associated with a transmission shaft (2) for adjusting the height of a table which is actuated by a corresponding gearmotor (9), comprising a threaded screw (1) which is meant to be fitted on the transmission shaft (2), a female threaded element (4) which is adapted to move along the threaded screw (1) as a consequence of the rotation of the transmission shaft (2), and at least one limit microswitch (3), which is meant to disconnect the gearmotor (9) from the power supply when the female threaded element (4) passes thereat; the device (100) is accommodated in a protective enclosure (8).

Description

[0001] The present invention relates to a stroke end adjustment device, particularly for adjusting the height of adjustable tables and the like.

[0002] More particularly, the invention relates to a stroke end adjustment device which can be actuated from outside.

[0003] It is known, for example in the case of vertically-adjustable tables actuated by motors, that in order to perform the chosen adjustment it is necessary to adjust the minimum and maximum strokes so as to determine the minimum and maximum height which can be reached by the table.

[0004] This adjustment is performed by means of a stroke end system which uses microswitches and corresponding wiring which are located in points where they can be broken, both during transport and during assembly, because they are arranged outside the table movement device.

[0005] This drawback combines with the fact that the external connections of the microswitches that determine the stroke end of the device for adjusting the height of the table are unsightly, since they are clearly visible under said table.

[0006] The aim of the present invention is to provide a stroke end adjustment device, particularly for adjusting the height of tables or of other movable elements and the like, which can be actuated from the outside in a simple manner.

[0007] Within the scope of this aim, an object of the present invention is to provide a stroke end adjustment device, particularly for adjusting the height of tables and the like, in which the limit microswitches and the associated wiring are arranged in points where they cannot be damaged.

[0008] Another object of the present invention is to provide a stroke end adjustment device, particularly for adjusting the height of tables and the like, in which the absence of microswitches arranged in positions in which they can be damaged accordingly leads to high reliability of the device.

[0009] Another object of the present invention is to provide a stroke end adjustment device, particularly for adjusting the height of tables and the like, which is aesthetically improved with respect to conventional devices because of the absence of microswitches and associated wiring arranged in a visible position.

[0010] Another object of the present invention is to provide a stroke end adjustment device, particularly for adjusting the height of tables and the like, which is highly reliable, relatively easy to provide and at competitive costs.

[0011] These and others objects which will become better apparent hereinafter are achieved by a stroke end adjustment device, particularly for adjusting the height of tables and the like, which is meant to be associated with a transmission shaft for adjusting the height of a table which is actuated by a corresponding gearmotor, characterized in that it comprises a threaded screw which is meant to be fitted on said transmission shaft, a female threaded element which is adapted to move along said threaded screw as a consequence of the rotation of said transmission shaft, and at least one limit microswitch, which is meant to disconnect said gearmotor from the power supply when said female threaded element passes thereat, said device being accommodated in a protective enclosure.

[0012] Further characteristics and advantages of the present invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of the device according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein:

Figure 1 is a plan view of the device according to the present invention;

Figure 2 is a front elevation view of the device according to the present invention;

Figure 3 is a view of a detail of the device according to the invention;

Figure 4 is a sectional view of the element shown in Figure 3; and

Figure 5 is a schematic view of the connection of a gearmotor to the transmission shaft to which the device according to the present invention is connected.

[0013] With reference to the above figures, the device according to the present invention, generally designated by the reference numeral 100, comprises a threaded screw 1, shown in detail in Figures 3 and 4, in association with a transmission shaft 2 for adjusting the height of a table; said shaft has, for example, a hexagonal cross-section, and is meant to be actuated by a gearmotor 9 which is directly connected thereto (as shown in Figure 5). The transmission shaft is connected to two bevel gear pairs with a screw-and-nut element which raise and lower the table (not shown in the figures). The threaded screw 1 is screwed onto the transmission shaft 2.

[0014] The threaded screw 1 is hollow and is provided, at its ends, with hexagonal holes 10 which allow to insert the transmission shaft 2 and therefore rigidly couple the screw 1 to the shaft 2.

[0015] A female threaded element 4 engages the threaded screw 1, which rotates synchronously with the transmission shaft 2, which is actuated by the gearmotor 9.

[0016] Therefore, the rotation of the transmission shaft 2 produces the correlated rotation of the threaded screw 1 and accordingly the female threaded element 4 moves on the threaded screw 1 in the direction dictated by the direction of rotation of the transmission shaft 2.

[0017] The adjustment device according to the invention further has a pair of microswitches 3 which determine the stroke ends of the transmission shaft 2, i.e., respectively, the maximum- and minimum-height positions in the case of a vertically-adjustable table.

[0018] The microswitches 3 can slide along a slotted guide 7, as shown in Figure 2, and this allows to determine at will the position of the microswitches and therefore to set the length of the stroke of the female threaded element 4, at the same time determining the minimum and maximum heights that can be achieved for the table that is vertically adjusted by said device.

[0019] The adjustment of the microswitches 3 along the slotted guide 7 is provided by means of knobs 5 which can be easily actuated from the outside of the device, which is entirely accommodated in an enclosure 8 which encloses the threaded screw 1, the female threaded element and the microswitches 3. The enclosure 8 is provided with holes for the passage of the adjustment shaft 2.

[0020] In practice, the rotation of the transmission shaft 2, produced by the gearmotor 9 connected thereto, turns the threaded screw 1, which is rigidly coupled to the shaft 2, and the female threaded element 4 moves along the threaded screw 1 in order to move in one direction or in the opposite direction, according to the direction of rotation of the transmission shaft 2.

[0021] When the female thread overlaps one of the two microswitches 3, the gearmotor 9 stops automatically; this accordingly determines the stroke end of the transmission shaft 2 to which two bevel gear pairs with a screw-and-nut element are connected, as explained earlier, which raise and lower the table to which the above-described adjustment device is connected.

[0022] In this manner, the enclosure 8, which is meant to contain all the elements of the adjustment device, allows to protect the microswitches 3 and the associated wiring, thus avoiding damage thereto caused by impacts that the device can suffer as a consequence of transport.

[0023] Moreover, the enclosure 8 allows to conceal the microswitches 3 and the wiring, which do not give the table an aesthetically pleasant appearance.

[0024] The knobs 5 allow to adjust the position of the stroke end microswitches 3 by acting outside the enclosure 8, in a very simple and practical manner.

[0025] The threaded screw 1, shown in cross-section in Figure 4, has, as mentioned, a threaded outer surface for the rotation of the female threaded element 4 and for its translatory motion along the threaded screw 1, while its internal surface has a hexagonal cross-section in order to couple to the outer surface of the transmission shaft 2, which is actuated by the gearmotor 9.

[0026] In practice it has been observed that the adjustment device according to the invention fully achieves the intended aim and objects, since it allows to provide a stroke end adjustment which can be performed very simply and most of all can be adapted to the most disparate dimensions to be obtained.

[0027] The adjustment device thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; moreover, all the details may be replaced with other technically equivalent elements.

[0028] In practice, the materials used, so long as they are compatible with the specific use, as well as the dimensions, may be any according to requirements and to the state of the art.

[0029] The disclosures in Italian Patent Application No. M199A000992 from which this application claims priority are incorporated herein by reference.

[0030] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A stroke end adjustment device, particularly for adjusting the height of tables and the like, meant to be associated with a transmission shaft (2) for adjusting the height of a table which is actuated by a corresponding gearmotor (9), characterized in that it comprises a threaded screw (1) which is meant to be fitted on said transmission shaft (2), a female threaded element (4) which is adapted to move along said threaded screw (1) as a consequence of the rotation of said transmission shaft (2), and at least one limit microswitch (3), which is meant to disconnect said gearmotor (9) from the power supply when said female threaded element (4) passes thereat, said device (100) being accommodated in a protective enclosure (8).

2. The device according to claim 1, characterized in that said threaded screw (1) has an externally threaded surface for engagement with said female threaded element (4) and an internal cavity which is meant to accommodate said transmission shaft (2).

3. The device according to claim 1, characterized in that said limit microswitches (3) are movable along a slotted guide (7) formed in said enclosure (8) and can be actuated by means of adjustment knobs (5) arranged outside said enclosure (8).

4. The device according to claim 1, characterized in that said transmission shaft (2) has a hexagonal cross-section.

5. The device according to one or more of the preceding claims, characterized in that said threaded screw (1) has a hexagonal internal crosssection for engagement with said transmission shaft (2).

6. The device according to claim 1, characterized in that said outer enclosure (8) has a passage hole for said transmission shaft (2) on which said threaded screw (1) is engaged.

Drawing