PT96918B - GAS CYLINDER - Google Patents

Description

DESCRIPTION

GIVES

INVENTION PATENT

No. 96,918

APPLICANT: Talleres GAIN, S. COOP. R.L., Spanish, based in Industrialdea-Pab. 20100-Lezo, Gipuzkoa, Spain

EPIGRAPH: Gas cylinder

INVENTORS: Javier Barandiaran,

Claim of the right of priority under Article 4? of the Paris Convention of 20 March 1883.

Spain, April 23, 1990, under the NQ 90.01140 'NP' MCC

RF 16722

-1Tallers GAIN, S, COOP. R.L,

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GAS CYLINDER

The present invention relates to gas-damping cylinders, normally used in industry for the regulation of different units, such as seat height, seat back, etc. and others, where it is necessary to absorb efforts.

It is known from the German patent P. 18 12 282.2, a type of gas cylinder consisting of a piston housed inside a cylinder, which is limited in its ride by extreme plugs, one called axle plug and the other plug valve. This cylinder is in communication- with another, concentric exterior, thus forming a chamber between them and a gas being disposed in that chamber and on both sides of the plunger, passing that gas from one chamber to the other through said plugs, depending on the requests to which the set is submitted from abroad.

These gas cylinders are usually assembled embraced by a bushing and a column tube, the column tube being closed at its free end by a washer in which the end of the main shaft or rod is received.

In this type of cylinders, the plunger limiting parts, called the shaft plug and valve plug, generally present very complicated geometries, being generally made of duralumin, with a considerable raw material cost and a va.¾

added machining value certainly high.

On the other hand, the difficulty of machining these parts has the consequence of limiting their geometric shapes, which implies a degradation of the technical characteristics and the effectiveness of the said plugs.

In turn, the column tubes receive the end of the cylinder's main shaft or rod through a set of washer, bearing and safety washer that are fixed to a larger and extreme flat washer, which also closes the end of the column tube . In certain cases, this washer, which has a reduced thickness, is welded to the edge of the end of the column tube and, in others, a washer, also flat, of greater thickness, which is fitted to the column tube by means of built-in points that serve as a seat for the washer.

In the first case, welding leads to a high manufacturing cost for this closing zone, and even so the necessary strength is not guaranteed.

In the second case, and despite the greater thickness of the washer, the problem of a lack of resistance in the washer is also not eliminated.

The object of the present invention is the constitution of the caps, shaft and valve, each constituted by three parts intertwined with each other and capable of being reinforced.

Another object of the present invention is the adoption of a ring washer for the column tube formed with the configuration of receptacle to which the end of said

column tube, fixing afterwards by embedded points, made according to a circular path.

To achieve these objectives, the valve shaft plugs that limit the stroke of the piston and receive the tube for the stroke of said piston, are made of thermoplastic material, preferably injected into the same mold and the same machine.

Axle plug is traversed by the cylinder's main shaft or rod and consists of three components, which are armed after being obtained. One of the aforementioned components leans as a stop inside the end of the outer tube of the cylinder and is provided inside with two boxes, one of smaller diameter that receives a scraper that acts against the rod and another of larger diameter, extreme, in which the end of the second component is housed.

This second component is also fitted inside the outer tube and comprises a circular recess, on the side of the previous one, for the arrangement of a toroidal seal. In turn, it is equipped with a box, facing upwards, in which another toroidal joint and the lower end are housed, as a circular protrusion of the first component.

the first component has a circular skirt that contacts the inside of the cylinder tube. and.receives.frontly the end of the inner tube that constitutes the chamber through which the piston circulates. In addition, this part is provided with an outer groove that establishes the communication between the piston chamber and the chamber that is established between the two main tubes of the cylinder.μΛ *

-4dro.

Each of these three components of the axle plug can be provided with other interior and / or exterior recesses, in which sealing joints can be placed to obtain the tightness of the assembly, both in the outer tube and inside and in relation to to the cylinder rod. These possibilities will be observed more specifically with reference to the attached drawings that will be described later.

valve plug is, in turn, made up of three components which are axially traversed by the valve shaft, which is provided at its lower end with a washer.

the first component of the valve plug receives in a lower box the washer, the diameter of its axial bore for the passage of the valve shaft being somewhat larger than the diameter of said shaft. Its exterior has a circular lower skirt that fits inside the piston chamber, with a trunk-conical elevation above it. The skirt, in turn, receives a toroidal gasket over it.

the second component is provided with a recess, partially occupied by the trunk-conical projection of the previous one, a circular lower recess in which the upper end of the inner tube fits and an upper frontal projection for its connection with the third component. At the same time, this second component is provided with an outer groove that establishes the communication between the chambers with its trunk-conical interior and with the axial bore of the first component.

third component is established between said second component and the upper stop tube of the cylinder. In this third component there is a washer on which the front of the stop tube rests, which is secured on an upper frontal projection of this third component.

The exterior of the third component is retracted on the wall of the inner tube, providing for a toroidal joint that is inserted in a circular recess. The second component partially receives from the lower end, facilitating the provision of a small internal box for a toroidal joint that embraces the valve shaft.

In turn, the column tube that receives the cylinder is provided with a rounded circular edge, on the inside of which sits a receptacle that fits by its own edge to the inside of the edge of the column tube. Once the receptacle is housed, embedding points are made, for example 3 or 4, according to a circular component, on which the end of said receptacle rests, being controlled between said points and the end of the column tube .

These and other details of the present invention can be seen in the embodiment given as a non-limiting example in the accompanying drawings, whose figures represent:

Fig. 1, a sectional elevation of a known gas cylinder;

Fig. 2, a gas cylinder that includes the plugs according to the present invention;

-6Α fig. 3, the valve cover components according to the present invention;

Fig. 4, the components of the axle cover according to the present invention;

Fig. 5, a sectional elevation of the column tube and its connection to the cylinder axis; and

Fig. 6, a section of the column tube closure receptacle.

According to fig. 1, there is a conventional gas cylinder, consisting of two tubes, ^ (1) exterior and (2) interior, between which the chamber (3) which includes gas is formed. The interior of the tube (2) receives the piston (5) and the shaft (6), which protrudes downwards. The displacements of the piston (5) by the action of the shaft (6) result in the gas in the inner chamber (4) passing either through (A) the valve plug (9) to the chamber (3) or through ( B) from the axle plug (8) to the same chamber (3), making an appropriate damping in both directions.

As can be seen, the upper valve plug (9) receives the stop tube (10) and is traversed by the valve shaft (7), its position being adjustable from above. This axis (7) is the one that shows a movement that allows gas to pass from the chamber (4), over the piston (5), to the groove (A) and to the chamber (3).

In this fig. 1, it is seen how the two valve caps (9) and the shaft caps (8) are made as single bodies, usually of duralumin, with complicated configurations, so that they are obtained

high cost parts, as a specialist in the field can appreciate.

In fig. 2 the formal modification of the present invention is observed, by separating the mentioned unit parts by sets of parts, three in this particular case, for each one. Of the other two fig. 3 and 4, it can be concluded that the realization of each of the components represented in them does not present any major mechanization problems because they are simple units and simple geometric configuration. If, in addition, they are made of thermoplastic material so that, by injection into a single mold, each group of three parts is carried out in one operation, the cost of each of them is greatly reduced.

In the case of fig. 2, it is seen how in this way the shaft plug can include a scraper (42) for the shaft (6), instead of a simple toroidal joint. Likewise, other formal variants for the components can be adopted to modify the situation of the same joints as the parts of fig. 1 or different ones.

In this regard, it also refers to the assembly, which raises problems in the conventional case, since it is necessary to introduce joints in certain positions of difficult access, which in addition increases the cost of the finished cylinder.

According to the components described in figs. 2, 3 and 4, the accommodation of joints and the like is simple and the components are assembled by pressure once the different joints are placed in the corresponding places.

-8For ο axle cover, fig. 2 and 4, the component (12) adjusts to the end of the tube (1), the axis (6) passes through the cavity (25), in the box (18) and pressures the protrusion (21) of the component (13). The latter has the circular recess (20) for a joint and in its box (22) it receives another joint and the projection (23) of the component (14).

The two components (13) and (14) are drilled axially, as well as (12), to receive the shaft (6). The component (14) has the collar (14) on which the tube (2) rests.

The valve plug, fig. 2 and 3, consists of the component (15), with the annular shoulder (26) for a joint, the inner cavity (29) for the valve shaft washer (7) and the conical stem (30) for its relationship with the component (16). The axial cavity (27) for the passage of the axis (7) is oversized in relation to the diameter of said axis (7).

The component (16) partially receives (31) the trunk-conical projection (30) and is provided with a lateral groove (32) that establishes the communication between the exterior and the housing (31). Above, a shoulder is seen that enters by pressure in the box (35) of the component (17), which includes a joint in its exterior (33).

The upper end (34) receives the gasket (43) on which the stop tube (11) rests.

From fig. 5 shows how the cylinder (1) is embraced by the bushing (36) and this, in turn, by the column tube (37). The end of the column tube has an edge (41) that embraces the edge

-9 of the receptacle (38), the latter being held in position by the sausages (40). The receptacle (38) receives the end of the rod (6) in its central hole, by means of bearings, joints and lock washers. The exact shape of the receptacle (38) is shown in fig. 6, which shows the edge (39) on which the edge (41) of the column tube (37) is also supported.

Claims (8)

1, - Gears cylinder of the type that has a concentric outer and inner tube, separated by a chamber, a plunger that moves inside the inner tube, are two end stops for said rod. equipped with gas passages from the outer chamber to the inner chamber, characterized l essentially because the valve plug, which is crossed centrally by the valve shaft, is divided into three fitted and cylindrical parts, one that receives the stop tube that surrounds the impeller, being supported by its outer part on the outer tube wall , another, underneath that, which is provided with a radial groove, supported on the outer tube wall and which receives the inner tube on its underside and a third whose exterior rests on the inner tube wall, while the axle plug is also consisting of three other pieces crossed by the main axis, one that receives the other end of the inner tube and is provided with a radial groove for communication of the two chambers and rests on the walls of the inner and outer tubes, another second supported on the outer tube wall and a third supported on the outer tube and the closure of said tube. 2. A gas cylinder according to claim 1, characterized in that the first part of the valve plug has a front protrusion which receives a washer on which the upper stop tube rests, a circular cavity at its lower end for reception of a toroidal joint, and a stepped central box, also at its lower end, on whose lower step a toroidal joint is received, and on its largest step a projection of the second part. I 3. Gas cylinder according to claims 1 and 2, characterized in that the second part of the valve plug is provided with an upper projection that fits into the internal step of the first part, connecting the radial groove, of which it is equipped , the exterior with the inferior interior of this part which presents a conical trunk housing for the reception of the third part and an inferior outer cavity for the reception 12 section of the cylinder's inner tube. 4.- Gas cylinder according to claims 1 and 3, characterized in that the third part of the valve plug is provided with an upward conical protrusion, on the outside of which cavities with steps are made, one on which the second part and the other for the arrangement of a toroidal joint, while the inner hole is staggered, with an upper cylindrical part with a diameter greater than the diameter of the valve shaft and a conical trunk part on which the lower washer of the shaft rests. valve. 5. Gas cylinder according to claim 1, characterized in that the first part of the axle plug has a smaller diameter projection downwards, which is cylindrical, said projection being fitted in an upper box of the second part together with a gasket, this second part having a lower outer circular cavity for the arrangement another toroidal joint. 6. - Gas cylinder according to claims 1 and 5, characterized in that the third part of the axle plug is provided with a staggered double cavity in its upper part, one of larger diameter that receives the lower circular cavity of the second part, while the smaller diameter includes a necklace -13 scraper for the main axis of the cylinder. 7. - Gas cylinder according to the preceding claims, characterized in that the two plugs, shaft and valve, are made of thermoplastic material and injected into a mold in one operation. 8. - Gas cylinder, with a column tube that embraces a bush that surrounds the outside of the cylinder and with the end of the cylinder shaft connected to the end of the said column, characterized in that the end of the column tube is closed by a piece in the form of a rounded outer receptacle, embraced laterally and by its external front, partially, by the column tube itself.