GB2265082A

GB2265082A - Extensible and tiltable supporting device

Info

Publication number: GB2265082A
Application number: GB9125937A
Authority: GB
Inventors: Philippe Rothschild
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-04-11
Filing date: 1991-11-16
Publication date: 1993-09-22
Also published as: GB9125937D0; FR2660984A1; FR2660984B1

Abstract

The maximum amplitude of an extensible and tiltable supporting device, is increased, for a given size of the device in its collapsed position, the device being formed by two telescopic elements 1 and 2, a cam-system 3, laid out as a closed circuit on one of the elements, a finger 6 engaging the cam system, said increased amplitude being the result of inserting the cam-finger between the male 1 and female 2 elements, and of said finger being shaped with a shoulder 20 (Fig. 2 - not shown), its tapered opposite part being introduced into the cam through a junction segment 7 linking the cam to the top horizontal plane 4 of the male component part, and the result of designing the cam grooves with a section of which at least one side is splayed towards the outside 21 (Fig. 2 - not shown), thus cooperating with said tapered finger 6. <IMAGE>

Description

EXTENSIBLE AND TILTABLE SUPPORTING DEVICE The present invention relates mainly to the increase of the gain in amplitude, for a given height, of an extensible and tiltable supporting device, manufactured through molding, and formed by two telescopic elements, of which the relative position is controlled by a cam-finger system, the cam system constituting a closed circuit, with only one possible position of the finger for the collapsed position of the device, on one of the elements, and layed out on a portion of the cylinder described by same element.

A hitherto known telescopic supporting device has the drawback of preventing a maximum extension, on account of the need to insert the finger, from outside towards the inside, through an opening of a diameter that is larger or at best equal to that of the operating part of the finger, at the bottom of the female part; on account also, for a device operating without the thrust of a coil spring, of the need to design cam segments, on a cylindrically shaped male component part of a given weight, with a strong slant, to allow the finger to slide through the cam segments, along their upper edges, without the intervention of a force, other than the one exerted by this weight (European Patent NOO 165 190, held by the present applicant).It also has the drawback of imposing a high precision manufacture to limit the clearance between the lateral contact points on the bottom of the female componenent part and those on the male component part, in particular when the device is in its extended position (European Patent 0 165 190).

The present invention relates to the increase of the reliability, the durableness, as well as that of the maximum amplitude of an extensible and tiltable supporting device, for a given size of the device in its collapsed position, manufactured through molding and and formed by two telescopic elements, of which the relative position is controlled by a cam-finger system, the cam system constituting a closed circuit, with only one possible position of the finger for the collapsed position of the device, on one of the elements, and layed out on an angular portion of the cylinder described by same element, in which a finger, solid with the other element, is moving, the finger being shaped with a shoulder which ensures a precise positioning in the housing provided at the bottom of the female component part, and introduced into the cam through a segment linking it to the top horizontal plane of the male component part, said cam having a section of which at least one side is splayed towards the outside, and cooperating with a tapered finger; the male component part being weighed down at its bottom end, by the increase of its diameter, and shaped in order to reduce the resistance to lateral movements, and in order to avoid notching the floor coating when in a tilted position, and last, in order to improve its sliding within the female component part, by the mere action of its own weight.

The invention also provides for one or two of the sides of the sections of some of the cam segments to be splayed, those sides being close to perpandicular with regard to a diametrical plane of reference, the other or both sides having a radial orientation to same diametrical plane, and also provides that the radial and perpandicular sides are reversed in the two sectors as defined on the one hand by the reference diameter, and on the other, by the radius perpandicular to same diameter, the sides perpandicular to the reference diameter being those closest to the groove, itself closest to the perpandicular radius, or being astride that radius.

The invention provides also for the adding of pin-point thicknesses, on the surface of the male component part, oriented in line with its generating line, or transversely in the shape of a discontinuous ring, positioned at the level corresponding to the lateral points of contact of the bottom end of the female component part with the male component part, in its extended position, lending more stability to the device, by reducing in this position, the magnitude of oscillations of the female component part, resting on at least one abutment, without tightening the measurements and manufacturing margins of the upper part of the male component part, prone to ovalization when cooling after moulding.

The invention also provides for the improvement of its gliding coefficient and for the diminishing of its wear rate, the finger is produced in a material different from the one used for the moulding of the male and female component parts.

The invention also provides for the enlargement and the mushroom-like shaping of the bottom part of the male component part, thus allowing for the decrease of the angle of the cam segments, thanks to the resulting increase in weight of the male component part.

The invention also provides for the positioning of the finger so as to have the lower part of the cylinder described by the finger's generating line, tangent to plane P that delimits the female component part at its lower end.

The invention also provides for the narrowing of the junction segment, close to where it leads into segment E of the camsystem, so as to avoid the finger's unwanted escape from the cam-system.

The invention also provides for the width of the junction section to grow narrow close to where it meets with segment E of the cam-system, thus preventing the cam-finger's unwanted escape from the cam-system.

The invention also provides for the beveling of the tip of the finger which slides into the housing at the bottom end of the female component part, so as to enable its fitting by sheer strength.

The invention also provides for the enlarged lower end of the male component part, to be elliptically shaped, thus reducing the resistance to lateral movements of the extensible supporting device when carrying heavy loads, and avoiding that it notches the floor lining when in a tilted position.

The invention also provides for the enlarged lower end of the male component part, to have a splayed shape, of which the level and bend are such, with regard to the plane described by the lower end of the female component part, that it helps preventing vibrations of the female component part with regard to the male component part, when the device is in a collapsed position, and the upper horizontal plane of the male component part is therefor resting on at least part of the inner horizontal surface of the female component part.

The described invention accordingly allows for the maximization of the device's extension as compared with its length when in a collapsed position, whilst facilitating the nesting/disengagement of its male and female parts, and increasing its stability, reliability and life-length.

A preferred embodiment of the extensible and tilting supporting device according to the present invention and as described in fig.1, is made up of a cam system (3) engraved on the male component part (1), a setback (9) and its paired abutment (8), a junction-section (7), made up of a section (12) with a narrow passage (13), and layed out angularly, joining section (E) of the cam system (3), followed by a bend and a vertical section leading to the upper horizontal plane (4), the slope of said section (12) being sufficient to avoid any bearing of the camfinger (6) moving exceptionally upwards in section (E), and penetrating the junction-section (7), of the upper horizontal plane (4) to the cam-system (3), said cam-finger (6) being integral with the female component part in its housing (26), and inner surface, the cam-system's lay-out (3) being made up in sequence of section (A), running upwards, then of section (B) running upwards with a slant towards the left hand side, then of section (C) running downwards with a slant towards the left hand side, then of section (D), running upwards, then after a bend, slanted towards the right, then of section (E) running downwards, with a bend before coming together with the upper part of section (A).

Figure 1 also shows the semi-elliptical part (5) of the lower end of the male component part (1), linked to its cylindrically shaped upper part by means of a splay (14).

Figure 2 is a sectional drawing of the male (1) and female (2) component parts of the device, at the AA' level of figure 1, representing the abutment (8) and its paired setback (9), the finger's profile (6), with a shouldering (20) and of which the tip moving inside the cam has a tapered shape, the cam being made up of grooves with a bottom (25), which apart from their sides with a near to radial orientation (21), have sides (22 and 24), at close to a right angle with the diametrical plane of reference BB', and therefor close to parallel to the radius (23) perpandicular to it, whilst having clearance angles to facilitate the withdrawing from the mould according to the joint plane BB'.

The characteristics of the cam-finger (6) and the junction section (7) determine the way the male and female component parts of the device are being nested and disengaged, as well as the way the cam-finger is being introduced and positioned into the female component part (2).

The characteristics of the cam-system (3) determine four phases in the functionning of the device, corresponding to the passing of the cam-finger through the cam sections A, B, C, D, and E.

The passing through section A corresponds to the disengaging of the male component part (1) from at least one support bearing system, defined on the female component part (2) by at least one projecting part (8), and on the male component part (1) by at least one setback (9).

The passing through segments B and C is a preliminary to reaching a support bearing position. By raising gradually the piece of equipment fast with its underlying supporting device, and as a result, the supporting device having been extended up to a pre-determined point, one triggers the rotation of the male component part (1). When the angle of that rotation is such that the cam-finger (6) is vertically in line with section D, the piece of equipment can again come to rest on the extensible supporting device, the extension of which corresponds to the height of the abutment (8).

The passing through section (D) disengages the paired abutment (8) from the cooresponding setback (9), whilst allowing for the possible return of the cam-finger (6) to the support bearing position, before reaching the highest point of its course through the combined effect of the piece of equipment's weight and of the opposite thrust applied by the lower side of the cam section that precedes this point.

The plotting of the cam-segment corresponding to phase E allows for the return of the male component part to a position, reached at the junction point with the phase A segment, allowing for the re-nesting of the abutment (8) fast with the female component part (2), though avoiding that cam-finger (6) enter it in the opposite direction, at the end of phase (A).

The last leg of th e extension/compression cycle permits the return of finger (6) to the position it held at the beginning of the cycle, by moving through segment A, from top to bottom.

The telescopic extensible supporting device according to the invention, is particularly suited to the manufacturing of legs with both a constrained height and a high extension ratio, without impacting the stability of the device, for all support +bearing positions.

Claims

1 Extensible and tiltable supporting device, of the type manufactured through moulding, and made-up of a male component part (1) and a female component part (2), a cam sytem (3) on one of the telescopic elements, the cam system constituting a closed circuit, and layed out on an angular portion of the cylinder described by same element, in which circuit a finger (6), solid with the other element is moving, and on the surface of which same element, at least one setback (9) is provided on the periphery, to house at least one abutment (8) fast with the other element, wherein, in combination, the cam-finger (6) aimed at being inserted between the male (2) and female (1) component parts, is shaped on the one hand with a shoulder (20) coming to rest on the inner surface of the female component part, insuring the precision of its positionning from the inside, in the housing (26) open-ended or not, provided at the bottom of the female component part (2), and on the other hand, is introduced into said cam system (3) through a junction segment (7) linking it to the top horizontal plane (4) of the male component part, certain segments of said cam system (3) having sections of which at least one side is splayed towards the outside, and on the other hand made up of a guiding tapered part moving within the cam system (3), and cooperating with segments which remain visible both when coupling and disassembling the telescopic elements, grooved on a male element, the bottom end of which, that always protrudes from the female element during the extension/compression cycle, having an increased diameter, shaped in order to reduce the resistance to lateral movements, and in order to avoid notching the floor coating when in a tilted position, and being thus weighed down to improve the sliding of the male (2) within the female (1) component part, whilst improving the extension ratio of the device.

2 Extensible and tiltable supporting device, as claimed in claim 1, wherein one or two of the segment section sides of the cam segments (3) are splayed, those sides being close to perpandicular with regard to a diametrical plane of reference (BB') corresponding to the molding plane, the other or both sides having a radial orientation to same diametrical plane, and also provides that the radial and perpandicular sides are reversed in the two sectors as defined on the one hand by the reference diameter, and on the other, by the radius perpandicular to same diameter (23), the sides perpandicular to the reference diameter being those closest to the groove, itself closest to the perpandicular radius, or being astride that radius.

3 Extensible and tiltable supporting device, as claimed in claim 1, wherein through the adding of pin-point thicknesses (10), on the surface of the male component part (1), oriented in line with its generating line, or transversely in the shape of a discontinuous ring, positioned at the level corresponding to the lateral points of contacts of the bottom end of the female component part with the male component part, in its extended position, lending more stability to the device, by reducing in this position, the magnitude of oscillations of the female component part (2), resting on at least one abutment (8), without tightening the measurements and manufacturing margins of the upper part of the male component part (1), prone to ovalization when cooling after moulding.

4 Extensible and tiltable supporting device as claimed in claim 1, wherein to improve the finger's (6) gliding coefficient and to diminish its wear rate, it is manufactured in a material different form the one used for the moulding of the male and female component part.

5 Extensible and tiltable supporting device as claimed in claim 1, wherein the bottom part male component part is enlarged and given a mushroom-like shape, thus allowing for the decrease of the angle of the cam segments, thanks to the resulting increase in weight of the male component part.

6 Extensible and tiltable supporting device as claimed in claim 1, wherein the cam-finger is positionned in such a way as to have the lower part of the cylinder described by the finger's generating line, tangent to plane P that delimits the female component part at its lower end.

7 Extensible and tiltable supporting device as claimed in claim 1, wherein the junction segment (7) width grows narrow at point (13), preventing the cam-finger's unwanted escape from the cam system (3).

8 Extensible and tiltable supporting device as claimed in claim 1, wherein the beveling of the finger's (6) outer tip, that penetrates the housing (26) at the bottom of the female component part, enables its fitting by sheer strength.

9 Extensible and tiltable supporting device as claimed in claim 1, wherein the enlarged lower end of the male component part is elliptically shaped, thus reducing the resistance to lateral movements of the extensible supporting device when carrying heavy loads, and avoiding that it notches the floor lining when in a tilted position.

10 Extensible and tiltable supporting device as claimed in claim 1, wherein the enlarged lower end of the male component part has a splayed shape, of which the level and bend are such, with regard to the plane described by the lower end of the female component part, that it helps prevent vibrations of the female component part with regard to the male component part, when the device is in a collapsed position, and the upper horizontal plane of the male component part is therefor resting on at least part of the inner horizontal surface of the female component part.