FR2689950A3 - Gas powered fluid spring for height adjustment of a seat. - Google Patents

Abstract

The gas spring comprises a first tubular element (1) at the closed upper end and at the open lower end and a second tubular element (2), with closed upper and lower end, which slides in the first tubular element (1 ). A piston (4), placed in the second tubular member (2), divides it into an upper chamber (25) and a lower chamber (24) filled with pressurized gas. The piston rod, connected to the upper end of the first tubular member (1), is crossed by a push rod (52) which opens a valve (53).

Description

i

  GAS-OPERATED FLUID SPRING

  FOR ADJUSTING A HEIGHT SEAT

  The invention relates to a fluid spring, more particularly a fluid spring using a pressurized gas instead of hydraulic oil to give better resistance than that given.

  by the fluid springs of the prior art.

  A fluid spring of the prior art comprises an inner cylinder and an outer cylinder, vertical and tubular The inner cylinder is arranged coaxially in the outer cylinder so as to define an annular space between them A lower hooking element ensures the sealing lower ends of the inner cylinder and the outer cylinder A piston is arranged,

  with freedom of movement, in the internal cylinder

  laughing so as to divide the interior of the interior cylinder into an interior hydraulic chamber,

  waterproof, and a non-hydraulic interior chamber.

  A piston rod connects the piston to the base assembly and passes through the lower fixed element. An annular seal is arranged, with freedom of movement, in the annular space so as to divide the annular space into a hydraulic, sealed outer chamber and a non-hydraulic outer chamber One element

  upper hooking ensures the watertightness of the

  upper mounts of the inner cylinder and the outer cylinder and has a passage which communicates between them the inner hydraulic chamber and the outer hydraulic chamber All the inner and outer hydraulic chambers, as well as

  the passage, are filled with a hydraulic fluid.

  A seat structure is carried on the upper hooking element A valve, actuated by 1 hand, is mounted on the upper hooking element and is operated selectively to open or close

  the passage An elastic body is arranged inside

  of the non-hydraulic outer chamber so as to force the annular seal to move in the direction of the element

upper hooking.

  When the valve is actuated to open the passage, that is to say when a force, directed downwards, greater than the stress force of the elastic body is applied to the upper hooking element, the inner cylinder and the outer cylinder move downward relative to the piston rod so as to pass the liquid, from the inner chamber, into the outer hydraulic chamber, through the passage Similarly, if one applies to the element upper catching force, directed downwards, lower than the stressing force of the elastic body, the elastic body pushes the annular seal in the direction of the upper catching member

  way to pass the liquid, from the hydrau-

  outer link, in the inner hydraulic chamber, thus moving the inner cylinder and the outer cylinder, up relative

to the piston rod.

  The assembly forming the base of a seat has a threaded hole for screwing with the threaded end of the piston. A sleeve is fixed on the assembly forming the base so as to prevent dust from entering the internal cylinder and the outer cylinder. Although you can easily adjust the height

  seat by means of the fluid spring mentioned above

  above, it turns out that the piston rod has a diameter of 8 mm It is not easy to support a seat structure (P) in a stable position with a piston rod of diameter 8 mm Build a larger diameter piston rod would increase the cost of producing the fluid spring due to the complex specific structure of the

piston rod.

  A main feature of the present invention is to provide a fluid spring which can give greater stability than the previous fluid spring while reducing its manufacturing cost. A second feature of this

  invention is to provide a fluid spring used

  reading a gas under pressure which can be used in a seat support so as to provide an effect

  stable elastic in said seat support.

  According to the present invention, the fluid spring comprises a first tubular element having a closed upper end and an open lower end and a second tubular element which can slide in the first tubular element The second tubular element contains a piston which divides it into a upper sealed chamber and a lower sealed chamber The piston rod passes through the closed upper end of the second tubular member to connect to the end

  upper, sealed, of the first tubular element.

  The piston has a valve which opens or closes when a push button provided on the upper, closed end of the first tubular member is operated. Other features and benefits of the

  present invention will appear better in the descrip-

  The following detailed description, including the drawings, which all represent a non-limiting form of the present invention and in which: Figure 1 shows a gas spring of the present invention; Figure 2 shows the gas spring of the present invention in service; Figure 3 shows the gas spring of the present invention attached to a sleeve of the seat member; Figure 4 shows, on an enlarged scale, a view of a second valve used in the gas spring of the present invention; and FIG. 5 represents, on an enlarged scale,

  a view of the second valve illustrating the configuration

  when closing the passage interconnecting the upper portion and the lower portion of an inner cylinder used in the gas spring

of the present invention.

  Referring to Figures 1 and 2, a gas spring of the present invention for use in a seat has a first tubular member (1) having an open bottom end, an open top end and a first sealing member (11) which hermetically seals the open upper end, as well as a second tubular element (2) having an open lower end which is sealed by means of a second sealing element (21), and an upper end open which is sealed

  by means of a third sealing element (22).

  It is important to note that the third sealing element (22) consists of several portions, each of which has a through central opening (23), the lower portion having, as shown in FIG. 1, a central opening 1 (231) larger whose purpose will be described below. A piston (4) is placed, with freedom of sliding, in the second tubular element (2) and divides the latter into a sealed upper chamber (25) and a sealed lower chamber (24) filled with a gas under pressure such as nitrogen The piston has an axial opening (41) which is closed by a valve (53) placed in the lower chamber

waterproof (24).

  In the preferred embodiment, the piston rod (4) has the shape of an elongated hollow tube (3) whose outside diameter is exactly the same as that of the opening (23) of two portions, thus allowing it to slide. , in an adjusted manner, in these two portions with a clearance existing between the exterior of the elongated tube (3) and the interior wall of the portion

  bottom of the third sealing element (22).

  The elongated hollow tube (3) has a radial opening (31) formed in its wall, near the place where the lower end of this same wall is joined to the piston (4) The upper end of the elongated tube ( 3) is securely connected to the first sealing element (11) placed in the first tubular element (1) In this way, the first and second tubular elements

  (1, 2) are connected to each other.

  In the elongated tube (3) is placed a push rod (5), one lower end of which is connected to the piston valve (4) and one upper end of which comes out of the elongated tube (3) to connect with a push button (52) The push button (52) contains an elastic body (51) which constrains the push rod (5) in the high position, thus pulling the lower end of the 1 push rod (5) so that in normal condition it

  closes the globe valve (53) of the piston (4).

  One thing to note is that the elongated tube (3) and the push rod (5) are made, in a known manner, to pass hermetically sealed in the central opening of the two portions of the third sealing element (22) and in the axial opening (41) of the piston (4), respectively The lower end of the second tubular element (2) is then fixed to an element forming the base of a seat support (6) and a seat part (not shown) on the upper end of the first

tubular element (1).

  In the upper part of the seat support, a handle element (61) can be placed to hold the first tubular element in the axis.

  (1), as shown in Figure 3.

  After a person sits on the seating part, they press the push button

  (52) downwards, thus pushing the lower end

  of the push rod (5) to open the globe valve (53) of the piston (4) The pressurized gas which is in the lower sealed chamber (24) will pass through the upper sealed chamber (25) through the axial opening (41) of the piston (4) and through the radial opening (31) of the elongated tube (3) The gas which enters the upper sealed chamber (25) continues to push the piston (4) downwards until the first tubular element (1) arrives at a predetermined height or until it is deliberately stopped At this time the globe valve (53) closes due to the descent of the piston (4) While the seat part descends, the person can release the push button (52), thereby closing the valve 1 with valve (53), when he believes he has obtained the

correct height.

  When the first tubular element (1) is at the predetermined height, the gas which is in the upper sealed chamber and the gas which is in the lower sealed chamber (24,25) are under the same pressure and the valve to valve (53) is in the closed position The upper chamber (25) has a volume smaller than that of the lower chamber (24) due to the presence of the elongated tube (3) and the gas therein is more compressed than the gas in the lower chamber (24) After a certain period of time, if the person wishes to raise the height of the seat part, they need only press the push button (52) again, thereby opening the globe valve The pressurized gas in the upper sealed chamber (25) is compressed by the weight of the seated person so that the gas will flow back into the lower sealed chamber (24) through the radial opening ( 31) of the tube

  elongated (3) and through the axial opening (41) of the piston.

  The gas entering the lower sealed chamber pushes the piston (4) upwards so that the

  seat portion, mounted on the first tube

  area (1), will rise to a height greater than the predetermined height The user can choose

  the height as in the previous way.

  Referring to Figure 4, in a preferred embodiment, the push rod (5) has

  an enlarged lower end (55) with a shoulder

  element (56) formed therein and it is connected to the valve (53) The piston (4) has a portion

  (42) of narrow section which is formed in the opening

  axial ture (41) of the piston (4) and which has an inner diameter 1 greater than that of the enlarged end (55), and a sealing element (7) grips the push rod (5) and it is placed in the axial opening (41) of the piston (4) near the portion (42) of narrow section The sealing element (7) has an annular projection (31) whose internal diameter is less than the diameter of the end enlarged (55) but greater than that of the portion (42) of narrow cross section of the piston (4) When the push rod (5) is pushed down to open the globe valve (53), the gas under pressure which is in the lower chamber (24) will pass into the upper chamber (25) by the clearance formed between the outer surface of the enlarged end

  (55) and the annular projection (71) of the sealing element

  size (7) and by the clearance formed between the outer surface of the enlarged end (55) and the surface

  interior of the portion (42) of narrow section.

  After closing the globe valve (53), as shown in Figure 5, the annular projection (71) serves as an additional seal, preventing the pressurized gas in the upper chamber (25) from backing up. bedroom

lower (24).

  An important characteristic of the seat which uses the gas spring of the present invention is that this seat is stable in comparison with the seat used with the fluid spring of the prior art The production cost of the gas spring of the present invention is weak, so that the seat made with such a gas spring is comparatively less expensive than with the spring

fluid of the prior art.

Claims (4)

  1 gas-operated fluid spring for adjusting the height of a seat comprising a first tubular element (1) and a second tubular element (2); characterized in that said first tubular member (1) has an open lower end, an open upper end and a first sealing member (11) which hermetically seals said open upper end; in that said second tubular element (2) has an open lower end, an open upper end, a second sealing element (21) which hermetically seals said open lower end, and a third   sealing element (22) which hermetically seals   ticks said open upper end, said third sealing element (22) having a through central opening (23), said upper end of said second tubular element (2) being fitted, with freedom of sliding, into said open lower end of said first element tubular (1); by the fact that a piston (4) is placed, with sliding adjustment, in said second tubular element (2) and that it divides said second tubular element (2) into an upper part (25) and a lower part (24 ) which is filled with pressurized gas, said piston (4) having an opening   (41) coaxial with the axis of said second tubular element   milk (2); in that an elongated tubular element (3) is placed in said first tubular element (1) and has a wall body having an axial opening aligned with said opening (41) of said piston (4), a first end fixed to said first sealing element (11) of said first 1 O tubular element (1) and a second end which, passing through said central opening (23) of said third sealing element (22), extends into said second tubular element (2 ) to securely connect with said piston (4), said wall body having a radial opening (31) formed therein near said piston (4); in that a push rod (5) is placed in said axial opening of said elongated tubular element (3) and has a first end which comes out of said axial opening of said elongated tubular element (3) and a second end which, in passing through said opening (41) of said piston (4), is connected with a valve (53) placed in said lower portion (24) of said second tubular element (2), to connect said first tubular element (1) with said second tubular element (2); by the fact that an elastic body (51) is placed on said upper end of said first tubular element (1) and constrains said push rod (5) upward to allow said valve (53) to close said opening (41 ) of said piston (4); in that a push button (52) is connected to said first end of said elongated tubular member (3) to push said valve (53) to open said opening (41) of said piston (4), thereby allowing gas under pressure penetrating into said upper part (25) of said second tubular element (2); and   by the fact that hermetic sealing elements   tick and holding are respectively placed in said central opening of said third sealing element (22), between said third sealing element (22) and said elongated tubular element 1 1 1 (3) and in said axial opening of said tubular element elongated (3), between said push rod   (5) and said elongated tubular element (3).   2 fluid spring as claimed in claim 1, characterized in that said third sealing element (22) consists of at least two portions of sealing elements, each of which has a central opening, said central opening (231 ) of said sealing element portion (221) which is adjacent to said piston (4) having a diameter greater than that of said sealing element portion which is remote from said piston (4).   3 fluid spring as claimed in claim 1, characterized in that said lower end of said second tubular element (2) is fitted and fixed in a lower end of said third tubular element (6), said third tubular element (6) having an upper end in which a handle element (61) is placed to hold in the axis said lower end of said first tubular element (1) when the latter (1) is placed in   said handle member (61).   4 fluid spring as claimed in claim 1, characterized in that said opening (41) of said piston (4) further has a section (42) which is narrower than the remaining section of said opening and which is formed therein spaced from said valve (53), said push rod (5) having a portion (55) which has a diameter greater than that of the remaining portion of said push rod (5), said narrow section (42) having an inner diameter greater than the diameter of said portion, a sealing element 1 (7) being installed around said push rod (5) in said remaining section and having an inner diameter less than the diameter of said portion (55) but greater than that of the remaining portion of said push rod (5).