JACK

Abstract

 A jack, either the scissor type or the Y type, with a combined nut based on two units, metallic (11) and synthetic (12), as well as a holder plate support arm with special characteristics. The metallic part of the nut is U-shaped and has two necks (13) that fit into the holes in the arm (25) and the synthetic part is longitudinal, has the screw spindle passing through it and is controlled in its movements in the interior of the metallic part. The holder plate support arm (25) is manufactured starting from a sheet or strip of a smaller size, thus achieving a considerable asving in material while making the jack sturdier.

Description

[0001] This invention relates to a jack, in particular for raising vehicles, of the type known as scissor jacks and Y-jacks, in all of which there is a threaded screw spindle that goes through a nut, thus generating the raising and/or lowering movement of one portion of the jack that comes into contact with the bodywork of the vehicle.

[0002] In all these units, nuts are known which are made entirely of synthetic material, plastics, as well as other nuts manufactured in plastic and metal, properly combined, with both versions being used indistinctly, depending on the mechanical stresses that the said nut is going to be subjected to.

[0003] Examples of combined nuts are known in references EP.A. 0320613 and EP.A. 0340551, in which nuts with synthetic bodies and side support lugs are provided, with these logs partially receiving metallic parts of other auxiliary parts that combine with them in order to increase the strength of the said lugs, reducing the amount of friction between the lugs made of synthetic material and the holes cut in the arms of the jack.

[0004] These known solutions are limited because in spite of the contribution of the metallic parts to the plastic logs, the strength of the nut is only increased to a certain degree.

[0005] On the other hand, in this kind of jacks, some are also known which are made of aluminium, whose aim is to reduce the weight of these units for obvious reasons. Nonetheless, the disadvantage of these jacks is that they are considerably more expensive than conventional metal jacks.

[0006] One object of the invention is to provide a jack that has a combined nut, made of synthetic materials and metal, that provides greater strength than conventional nuts of this type.

[0007] Another object of the invention is to provide a jack with a combined nut which is very easy to keep inside it.

[0008] Another object of the invention is to provide a jack with at least one arm made of aluminium, which uses a lower amount of material at the start of manufacturing.

[0009] Another object of the invention is to provide a jack with at least one arm made of aluminium, which is more economical than conventional ones.

[0010] In order to put these objectives into practice, the invention claims a nut produced by means of combining two bodies made of different materials, synthetic and metallic, of which the metallic body has a general U-shape, with outwardly projecting necks made on its wings or sides, with these necks duly aligned and through which insertion of the nut into the wings of the corresponding arm of the jack is carried out.

[0011] This U-shaped part is provided with a centrally-situated hole in its base to allow the screw spindle to pass through, while between its wings or sides it receives another part made of synthetic material, generally cylindrical in shape and longitudinally hollow, with its interior screw threaded for the passage of the above mentioned screw spindle.

[0012] Both bodies, synthetic and metallic, are provided with the corresponding means both to control the possible axial movements of the internal synthetic body in relation to the metallic exterior, and to prevent the turning of the said interior inside the exterior. As will be explained later, these means can be of diverse types.

[0013] The nut which is so produced is situated in the arm of the jack, fitting firstly the metallic body, which is inserted at pressure between the wings that the U-shaped section of the said arm provides, so that the two projecting necks, produced by pressing or drawing, for instance, become housed in the corresponding holes in the said wings.

[0014] After this, the synthetic part is placed inside the metallic part, fitting one of its longitudinal ends in the hole in the base of the metallic part.

[0015] As already stated, this synthetic part is controlled between the internal walls of the wings of the metallic part, so that the synthetic part is prevented from turning. At the same time, the means provided in the corresponding shape in both parts, metallic and synthetic, also allow the latter to be controlled in its possible axial movements inside the metallic part.

[0016] As will be easily deduced, the metallic part is the part of the nut that is submitted to stresses, although no wear or maladjustment is produced due to the metal contact between the arm and the said part. The synthetic part of the nut works under compression inside the metallic part and, for this reason, its working life can be considered unlimited.

[0017] In order to achieve the other objectives of the invention, it proposes an arm, particularly one made of aluminium, as stated previously.

[0018] In the same way that in the conventional technique the forward portion of the arm of the jack turns on the base body, in Y-jacks the forward portion that supports the holder plate has wings or sides whose height is substantially greater than the greatest height of the rest of the wings of the arm.

[0019] This make it necessary to start from a metal sheet or strip whose width corresponds to the sum of the lengths of the base of the U-section and of the heights of the wings at the point of the arm with the greatest height, which corresponds to the end where the holder plate is positioned.

[0020] In accordance with the invention, the starting height of this metal sheet or strip can be reduced, so that a considerable saving of material is obtained, which in practice means a noticeable reduction in the cost of the raw material, aluminium, a very important detail that enables the jack to be produced more cheaply.

[0021] To do this, the invention proposes an arm in which the height of the wings at the end toward the holder plate position is essentially equal to the maximum height of the wing in the rest of the arm. This is achieved by providing the end of the U-shaped base, at the end near the holder plate, with an outwardly convex curvature that rises toward the forward part of the arm at the said end of the holder plate position.

[0022] As will be described later in relation to the accompanying drawings, the outwardly convex curvature can also reach to the lower edges of the wings at the end of the arm.

[0023] All these and other details of the invention will be appreciated in greater detail and clarity by referring to the sheets of drawings which are attached, in which the following are represented in a non-restrictive manner.

• Figure 1 is an elevation of a Y-type jack that includes the two aspects of the invention.
• Figure 2 is a perspective that shows a preferred solution of the nut, in accordance with the invention.
• Figures 3, 4 and 5 are three views of the nut shown in Figure 2.
• Figure 6 is a perspective view of a preferred solution for the synthetic part of the nut, according to the invention.
• Figures 7, 8 and 9 show three views of the synthetic part of the nut shown in Figure 6.
• Figure 10 is a perspective view of the metallic part of the nut, according to the invention.
• Figures 11, 12 and 13 are three views of the metallic part shown in Figure 10.
• Figures 14 and 15 are an elevation and the top view of the same for a conventional arm.
• Figure 16 is a development of the conventional arm.
• Figures 17 and 18 are an elevation and a top view of the same for the arm in accordance with the invention.
• Figure 19 is a development of the arm shown in Figures 17 and 18.

[0024] In accordance with Figure 1, we can observe a Y-jack with a main body (1) articulated on a support foot (2), an arm (3) articulated to the body (1) by the shaft (9), with the free end of this arm receiving the holder plate (7), on which the bodywork of the vehicle is received. A crank winding handle (6) is connected to the threaded screw spindle (4), which connects the nut (5) in the body (1) and the cross member of the position (10) in the arm (3). On the arm (3), we can see its outwardly convex curved area (8) that constitutes one of the objects of the invention.

[0025] Looking now at Figure 2 and also at Figures 3, 4 and 5, we can appreciate the nut unit, with the external U-shaped metallic part (11) and the internal synthetic part (12). The wings or sides of the metallic part (11) have the protruding aligned necks (13), as well as the hole (14) cut in its base to enable the screw spindle (4) to pass through, and the seating for the synthetic part by means of one of the conical chamfers (12') of the synthetic part (12).

[0026] As far as the synthetic part (12) is concerned, it has a generally cylindrical shape and its interior is hollow and screw threaded longitudinally in order to house the threaded screw spindle.

[0027] In this preferred solution, which is not excluding, the turning of the synthetic part is controlled by means of the rectangular ledges or ribs (15) that it is provided with, whose side faces (15A) (Fig. 6) are adjusted to or are close to the internal sides of the wings of the metallic part, which means that it is impossible for the synthetic part to rotate once that it has been received inside the metallic part.

[0028] It can also be appreciated how the forward portion of the wings have facing legs (16) on which one of the external faces (29) of the ledges (15) is supported, thus preventing the axial movement of this synthetic part.

[0029] It will be understood that there might be innumerable practical solutions, either to prevent the turning of the synthetic part (12) in the interior of the metallic part (11) or to prevent the axial movement of the synthetic part in the said interior.

[0030] It is possible to adjust or not the faces or sides (15A) of the rectangular ledges (15) to the internal surfaces of the wings.

[0031] It would also be possible to make recesses in the internal faces of the wings in order to receive the oversized end faces (15A), with which the axial control of the synthetic part (12) would also be carried out.

[0032] Although two ledges (15) are procured on the synthetic part (12), a single ledge could also be used, etc.

[0033] Technically, any expert can devise solutions to achieve this objective very easily and it must be well understood that, as stated previously, there might be innumerable possibilities.

[0034] In the same way, the axial control of the synthetic part (12) in the interior of the metallic part (11) can be put into practice in accordance with the way described or by any other means. For example, holes or recesses could be made in the base of the metallic part, into which protrusions on the synthetic part could be received by pressure, by clipping together, etc.

[0035] To this effect, it must also be pointed out that any expert can work out mutual corresponding means between both parts in order to prevent the axial play of the synthetic part.

[0036] From Figures 6, 7, 8 and 9, we can deduce the particular geometry of the synthetic part (12), whose ends (12') are chamfered or bevelled so that one of them can fit into the hole in the base of the metallic part. The two rectangular ledges or ribs (15) are evenly distributed, with their side faces (15A) being responsible for preventing the part from turning and the other sides (18, 19) being responsible for the axial control.

[0037] According to Figures 10, 11, 12 and 13, we can appreciate the shape of the metallic part (11), on which we point out the necks (13) for housing in the wings of the body-arm (1), the hole (14) to allow the screw spindle (4) to pass through, and the seating in the chamfered area (12') of the synthetic part (12), as well as the forward lugs (16) for the axial control of this part

[0038] In accordance with Figures 14 and 15, we can appreciate the elevation of a conventional arm with its end (9) to establish its rotation on the body (1) and its other end for placing the holder plate (7) and the point (10) for fixing the cross member.

[0039] According to this known traditional technique, the height between the upper end (20) and the lower end (21, 22) is considerably greater than the maximum height of the rest of the arm, determined in this case by the corresponding height between the end points (A, B) of the wings. All this means that on manufacturing the arm, starting from a longitudinal metal plate or strip, the plate or strip needed must take in the development of the arm in Figure 16, according to which the width of this plate or strip must be at least equal to the distance between the curved areas of the positions (29) and normally a little more.

[0040] If we observe the scope of the arm of the jack (25) according to the invention, Figure 17, we can appreciate that the lower left end (26) is shaped with an outwardly convex curved area (26), so that it makes the height of the forward or front end (27), between its highest point (20) and its lowest point (24) essentially equal to the maximum height between the two end points (A, B) of the rest of the wing of the arm. Therefore, if we observe the development of the arm in Figure 19, we can see how the width of the starting plate or strip is limited by the distance A-B, essentially equal to the distance existing between the points (20), thus achieving, compared to the development of the conventional arm, an appreciable saving in material, as the plate or strip is narrower.

[0041] In practice this means a saving in material corresponding to the width of each longitudinal end, i.e. with a side length equal to that of the arm, and normally slightly more, and double. As the starting material used is aluminium, which is considerably expensive, the saving in material means a considerable economic saving on the arm and consequently on the jack, which is another of the objectives of this invention.

[0042] Once that the nature and advantages of this invention have been described, it is important to point out its non-restrictive character, inasmuch as changes in the shape, materials or dimensions of its constituent parts will not in any way alter its essence, as long as they do not mean a substantial variation of the whole assembly.

Claims

1. Jack, applicable either to scissor type jacks or to Y type jacks, that have a body (1) mounted on a support foot or base (2) and an arm (3) that pivots on the body, in which the upper end of the body (1) and the arm (3) are connected by means of a screw spindle (4) that passes through a nut (5) in the said body and connects to a cross member in the arm (3), that supports the holder plate, with this nut (5) being composed of two parts made of different materials, metallic and synthetic, respectively, which are connected to each other, in that the arm (3), at the holder plate connection end (20) has a wing dimension or height greater than the greatest average height between the ends (A) of the wings and their base (B), which is characterised by:

- a nut (5) based on a U-shaped metallic body (11), on whose wings or sides are established outwardly protruding aligned necks (13) for their insertion into holes in the wings of the body (1) and a central hole (14) in its base for the passage of the screw spindle (4), with the hollow interior of this part receiving another part made of synthetic material (12) which occupies a position perpendicular to the said base and is screw threaded internally for the passage and connection of the screw spindle,

- corresponding means arranged in the external metallic body (11) and on the internal synthetic body (12) that control the possible relative axial movements of the body (12) in relation to the body (11).

- corresponding means in the external metallic body (11) and on the internal synthetic body (12) to prevent the rotation of the said internal body in relation to the external one.

- an arm (25) with a U-shaped transversal cross section, in which the greatest height of the wings, from their base (B) to the free upper end (A) of these wings, in the portion of the wings starting from their forward or front end, to which the holder plate (7) is connected, is noticeably equal to the height or maximum dimension (27) between the lower front end (24) of the base (B) and the upper one (20) on which the holder plate is fitted, with the base (B) having an outwardly convex curvature area on its forward portion (8), that extends to the forwards end of the arm.

2. Jack, in accordance with claim 1, characterised in that the internal synthetic part (12) is preferably of a generally cylindrical shape and is provided with at least one centred ledge or rib (15) of a quadrangular shape, that procures two parallel faces on its sides (15A) that are vertical and are close, at least, to the internal side faces of the wings of the external part (11), with the free ends of the cylindrical portions of the internal part (12) being provided with annular chamfers (12'), one of which becomes housed in the entrance of the hole (14) in the base of the external body (11).

3. Jack, in accordance with claim 1, characterised in that the means to control the internal part made of synthetic material (12) in its housing in the external part (11) consist of a set of facing inwardly protruding lugs (16) formed at the ends of the wings of the said external part, with the cylindrical portion of the internal part (12) resting on these lugs, while in turn one of the ledges or ribs (15) of the internal part is supported on the rear faces of these lugs.

4. Jack, in accordance with claim 1, characterised in that the means of axial control between the external body (11) and the internal body (12) is established between the ledges or ribs (15) of the said internal body and the side walls of the wings of the external body.

5. Jack, in accordance with claim 1, characterised in that the means of axial control between the external body (11) and the internal body (12) is established between the ledges or ribs (15) of the said internal body and the walls of the base of the external body.

Drawing