AN ADJUSTABLE OLEOPNEUMATIC AMORTIZED SUPPORT COLUMN, FOR CHAIRS AND ARMCHAIRS

Abstract: A chair oleopneumatic adjustable and amortized column support comprising: a first empty cylindric body (A), which basis is rigidly connected to the basement of the chair and a second cylindric body (B) as an upper coaxial slidable stem inside the first, which upper end is secured under the seat of the chair; a coaxial bar internal of command movable vertically (8) by command lever under the seat that protracts inside the second and the first body, associated to: first slidable piston means (5) into the first body and blocked externally to seal on the second body (B), that form two chambers respectively upper and lower chamber (X-Y), containing oil, with valve means (10) to allow or to prevent the passage of oil by one chamber to the other to the purposes to make possible the height variation by means of the actuation of said command under the seat; characterized in that: two second floating piston means are provided set between said first and second body, one above (6) and one under (4) said first piston means realizing a couple of oil chambers displace ensemble inside the first body (A).

Description: An adjustable oleopneumatic amortized support column, for chairs and armchairs. The present invention has for object an adjustable oleopneumatic amortized support column, for chairs and armchairs. The innovation finds particular even if not exclusive application as support sprung structure regulable in height for office chairs. In prior art adjustable oleopneumatic amortized support comumn with an oil and an air chamber in the column is known. A first solution is disclosed in DE-1529432 ( Biltein ) which describes the realization of a regulable central column oleopneumatic support, particularly for chairs comprising: - a first tube, which basis is rigidly connected to the basement of the chair and - a second, wrapping the first, superior tube coaxially slidable as a stem in it, which upper end is secured under the seat of the chair; - an internal command coaxial bar vertically movable by lever under the seat, that protracts within the the first and second body, associated to - first piston slidable means, slidable inside the first body forming two chambers respectively an upper chamber and a lower chamber, containing oil, with valve means to allow or to prevent the passage of oil by one chamber to the other to the purposes to make possible the height variation by means of the actuation of said lever under the seat; - second freely slidable floating piston means into said first tube and under said first piston means, that defines and delimits said lower chamber and realizes a bottom chamber that contains air or compressible gas to offer a function of spring. A second disclosed solution is IT-41632A/85 (in the name of same applicant) that provides the realization of a similar support but wherein the second tube is slidable internally to the first rather than externally; - the second piston means are fixedly inserted in the first tube and the second tube slides inside said second piston means; - the bottom chamber presents a lower plug valve for charging and discharging respectively the air chamber pressure. Both the aforesaid first and second solutions present however substantial structural lacks and such to prevent a practice and reliable realization: - the first solution in particular does not allow an automatic elongation of the column, but for said elongation it is necessary to operate a pull in open condition of the intercommunication device, this operating being complex and tiresome and over all hindered from the presence of the air basis chamber that involves an elastic yelding even in drive. - if the second solution solves this problem (for the presence of the second tube (body) that immerses as a further piston inside the basis chamber) allowing an autoelongation of the column by intercommunication open device between the two oil chambers, presents moreover structural complexity of fixation of the second means to the piston, resolvable only by high production costs particularly for the internal working necessity (annular fixation recess) of the first body. Further disadvantages of the second solution derive by a system of practical small valve means ensemble and less reliable, principally for the lack (in a oil hole passageways) where the ring seal or gaskets (OR or O-Ring) are obliged to pass in reciprocation from one chamber to the other, each time that the operator acts on the command lever to lower or to lift the seat, said moving across the open holes causing the inevitably breaking of said gaskets. Finally the device does not present valid axial guide means as in the first solution, that involves the further damaging of said seals and an inevitable misalignment for oscillation. Furthermore is to point out that in the solution disclosed in IT-41632A/85 does not provide amortisement means, and in the solution of DE-1529432 (Biltein) there are always resistances to the elongation, forming frequent upper air infiltrations for the depression created action during the extraction in elongation. For both the solutions: - there is presence of a necessarily limited chamber of air, (in the first solution for said second piston means and in the second solution for said second body (tube) that is interiorly shut and acts as a piston stem as impenetrable body); - there is always resistances to the elongation; - present seal problems of the oil. Purpose of the present invention is to obviate the mentioned drawbacks. This and other purposes are reached with the present invention as claimed solving the exposed problems by means of a chair oleopneumatic adjustable and amortized column support e comprising: - a first empty cylindric body, which basis is rigidly connected to the basement of the chair and - a second cylindric body as an upper coaxial slidable stem inside the first, which upper end is secured under the seat of the chair; - a coaxial bar internal of command movable vertically by command lever under the seat that protracts inside the second and the first body, associated to: - first slidable piston means inside the first body and blocked externally to seal on the second body, that form two chambers respectively upper and lower chamber, containing oil, with valve means to allow or to prevent the passage of oil by one chamber to the other to the purposes to make possible the height variation by means of the actuation of said command under the seat; characterized in that: - two second floating piston means are provided, set between said first and second body, one above and one under said first piston means realizing a couple of oil chambers displaceable ensemble inside the first body, in the moment of the sat, with amortizing effect. This solution makes possible a displacement of the oil chambers ensemble inside the first body (being, said chambers, above the compressed air chamber) and simultaneously eliminate the decompression effect and any oil leakage that easily could happen in the previous solutions. Said valve means include an axial puil-reciprocable (axially alternately movable in reciprocation by said means of a lever command) that involves three ring seals and slides into said second body in an intermediate chamber formed by a cartridge case and counter cartridge case that involves two series of holes of different height level and in which the excursion of said draw deplaces: - by a closed position with the intermediate sealing means between said two series of holes, interdicting for this the flow of the oil from one chamber to the other, - at an opened position, with intermediate sealing means coincident with one of said holes series in cyclic coincidence, but not besides this with openings of the flow of oil. With this solution, the interested sealing cannot deteriore or underlie damaging. Advantageously said second body is: - internally hollow and - its hollow is opened interiorly toward said basis chamber and extends until under said intercommunication device between the two oil chambers in said second body. Being the second body inferiorly hollow, the lower air/gas chamber is notably widened improving sensitively the elastic effect without modify the external encumber. As much advantageously, in the lower part of said first body, is set a compass of guides and beaten that allows: - to guide axially the lower part of said first body and - to act as lower stop means of said first piston means interposed with a respective floating piston means. In such way realizes the limit condition to control the excursion downwards of the second body if compared to the first even if the pressure of the gas in the basis chamber does not ditch to contain the upperplaced charge. Condition particularly important in the dynamic actuation (dynamic charge) that can overcome (at the moment of the sitting) sensitively the static charge (person position already sat). Important is the fact that this column is utilizable even in absence of air or gas in the chamber, because, putting the valve means in intermediate position, the seat can be placed manually to the desired height and in that blocked point, putting said valve means in rest position. These and other advantages will appear by the successive specified solutions preferentially described in one way of realization with the help of the accompanying drawings which particulars of execution are not to be considered limitative but exemplificative solely. Figure 1 represents a view in axial section of the column; Figure 2 represents an enlarged view in axial section of the central portion of the column with the valve means in rest position (interdict flow). Figure 3 represents a view with the valve means in intermediate position (consented flow) . In the figures is well disclosed a chair oleopneumatic adjustable and amortized column support e comprising: - a first empty cylindric body (A), which basis is rigidly connected to the basement of the chair and - a second cylindric body (B) as an upper coaxial slidable stem inside the first, which upper end is secured under the seat of the chair; - a coaxial bar internal of command movable vertically (8) by command lever under the seat that protracts inside the second and the first body, associated to: - first slidable piston means (5) inside the first body and blocked externally to seal on the second body (B), by means of blockage means (5', 5") comprising sealing means (OR-5"' and 5""), that form two chambers respectively upper and lower chamber (X-Y), containing oil, with valve means (10) to allow or to prevent the passage of oil by one chamber to the other to the purposes to make possible the height variation by means of the actuation of said command under the seat; characterized in that: - two second floating piston means are provided set between said first and second body, one above (6) and one under (4) said first piston means realizing a couple of oil chambers displace ensemble inside the first body (A). Advantageously said second body (B) is internally empty and its hollow is opened interiorly toward said basis chamber (Z) and extends until under said intercommunication device between the two oil chambers. inferiorly in said first body is set a cylinder guide stop (3) that allows: - axially guiding the lower part of said first body and - first piston means (interposed in a respective floating piston) stroke delimiter stop means. 1 The two floating pistons (4, 6) are in O-Ring seal shape and are slidable freely both 2 long the first body and long the second body, in this way the oil chamber (X, Y) 3 becomes floating also and above and under this, forms two air chambers, one 4 principal lower chamber (Z) for the amortisement and one upper chamber for 5 interspace (Z') in the moment of the sat. 6 The lower guide (3) is conveniently in plastic material. 7 The structure of the entire device includes furthermore in the internal of the second 8 body (B):- 9 - a command bar (8) to consent the opening and so the flow of the oil from a chamber I 0 to the other and so the regulation of the height of the seat. I I - an upper tubular stop means (9) to hold in guide the upper part of the command 1 2 bar (8). 1 3 - a piston casing (12) to hold in guide the lower part of the bar of command (8) 1 4 with stop function by means of two seal rings (12' and 12"), placed externally above 1 5 and under the holes series 10n' of said piston casing and the holes series Bn' of said 1 6 second body (B), the seal ring 12' to prevent the passage oil in the upper interspace 1 7 and the seal ring 12" to prevent the passage oil through the two holes series Bn' and 1 8 Bn" of the second body (B). 1 9 - a piston (10) that slides, enlivened from the bar of command (X), internally the 2 0 piston casing (12) with three external seal rings. One upper seal ring (10') to 2 1 prevent the passage oil in the interspace between command bar (X) and guide means 2 2 (9) through the hole above the piston casing (12), one intermediate seal ring 2 3 (10") to consent or to interdict the passage of the oil from a chamber to the other 2 4 (x-y), one lower seal ring (10"') to prevent the passage of the oil to the internal of 2 5 the lower piston casing guide means (13). 2 6 - a lower piston casing guide means (13) inferiorly closed as a cartdridge case to 2 7 house a helical spring (11 ) with a annular with an upper external seal ring (13') to prevent the passage of the oil in the air chamber (2). - a helical spring (11 ) to cause the push of the valve means (10 and 8) in rest position and to close so the flow of the oil by one chamber to the other and to block the regulation of the height of the seat. - a lower inside tubular stop (14) to sustain the lower piston casing (13). - a seal ring "Seeger" for holes (7") for the blockage of all the inserts in the interior of the second body (B). The inserts 8, 9, 12, 10, 13, 14 are conveniently in plastic material. We understands that moving the draw valve (Fig. 2 - Fig. 3) is possible interconnect or not the two oil chambers (X-Y) allowing the elongation or shortcut of the column (lifting or lowering the seat of the chair) (passage allowed fig. 3) or its respective blockage (passage interdict Fig. 2). The channels for the passage of the oil through the valve system and the holes series have been calculated to consent the control of the descending speed and climbed of the seat. In the lower part of the column is foreseen a valve with closure (1 -2) for air charging in the air chamber (Z). In the upper part of the first cylindric body (A) is inserted the upper guide (7') in plastic material of the second body (B) blocked by the hole ring "Seeger" that acts even by hookup means of the closure upper ring (7) also realized in plastic material that however allow the passage of the air in inlet and in exit in the moment of the sat (when the two floating seals (6 and 4) and consequently the internal oil chambers (x and y), displace ensemble downward and then upward for effect of the push of the compressed air in the lower air chamber (Z).

Claims: Claims 1. A chair oleopneumatic adjustable and amortized column support comprising: - a first empty cylindric body (A), which basis is rigidly connected to the basement of the chair and - a second cylindric body (B) as an upper coaxial slidable stem inside the first, which upper end is secured under the seat of the chair; - a coaxial bar internal of command movable vertically (8) by command lever under the seat that protracts inside the second and the first body, associated to: - first slidable piston means (5) inside the first body and blocked externally to seal on the second body (B), that form two chambers respectively upper and lower chamber (X-Y), containing oil, with valve means (10) to allow or to prevent the passage of oil by one chamber to the other to the purposes to make possible the height variation by means of the actuation of said command under the seat; characterized in that: - two second floating piston means are provided set between said first and second body, one above (6) and one under (4) said first piston means realizing a couple of oil chambers displace ensemble inside the first body (A). 2. A seat support column as claimed in claim 1., characterized in that said valve means (10) include a reciprocable draw piston (10) that involves three seal rings (10', 10", 10"') sliding inside said second body (B) in an intermediate chamber formed by a lower piston case (13) and an upper piston case (12) that involves two series of holes to different height level (10n\ 10n") and in which the excursion of said draw piston (10) deplaces: - from a position with the intermediate sel ring between said two series of holes (Fig. 2), interdicting for this the flow of the oil from one chamber (X) to the other (Y) , - to a position substantially coincident with these which holes series in cyclic coincidence (10n") but not besides this, with opening of the flow of oil. 3. A seat support column as claimed in claim 1., characterized in that said valve means (10) include a reciprocable draw piston (10) that involves three seal rings (10', 10", 10"') sliding inside said second body (B) in an intermediate chamber formed by a lower piston case (13) and an upper piston case (12) that involves two series of holes to different height level (10n\ 10n") and in which the excursion of said draw piston (10) deplaces: - from a position with the intermediate sel ring between said two series of holes (Fig. 2), interdicting for this the flow of the oil from one chamber (X) to the other ( Y) , - to a position substantially coincident with these which holes series in cyclic coincidence (10n") but not besides this, with opening of the flow of oil; - said holes series being at least in cyclic coincidence (10n") bevelled or joined. 4. A seat support column as claimed in claim 1., characterized in that said second body (B) is internally hollow and its hollow is opened inferiorly toward said basis chamber (Z) and extends until under said intercommunication device between the two oil chambers in said second body that extends until under said valve means. 5. A seat support column as claimed in claim 1., characterized in that inferiorly in said first body is set a lower tubular stop guide means (3) allowing: - axiaily guiding the lower part of said first body and - to act as lower stroke delimiter stop means of said first piston means interposed with a respective floating piston means. 6. A seat support column as claimed in claim 1 ., characterized in that the two floating pistons (4, 6) are in seal ring shape and are slidable freely both long the first body and long the second body, in order that the oil chamber (X, Y) becomes also floating and above and under this, a respective two air chambers if formed, one principal lower air chamber for the amortisement (Z) and one upper air chamber for interspace (Z'). 7. A seat support column as claimed in claim 1., characterized in that the structure of the entire device includes furthermore in the internal of the second body (B) a lower tubular stop means (14) in plastic material that bears a lower closed piston case (13) also in plastic material containing an helical spring means (11) and superiorly a seal ring (13') to prevent to the compressed contained air in the lower air chamber (Z) to pass in the oil upper chamber and wherein said lower closed piston case (13) operates together with an upper piston case (12) and with two respective hole means (10n'-10n") and two exterior seal rings (12'-2") against the second body (B) that have the corresponding pitch radial holes (Bn'-Bn") in said second body, being intercalated at them in intermediate position and in upper position, containing a draw piston valve (10). SUBSTITUTE SHEET

Inventors: DE SABBATA CLAUDIO, DE SABBATA RENATO, FANTINI LUCIO, DE SABBATA, CLAUDIO, DE SABBATA, RENATO, FANTINI, LUCIO
Applicants: LIFTER SRL, LIFTER S.R.L.
Application year: 1990
Main classification: A47B9
IPC codes: A47B9, A47C3, A47C7, F16F9