EP0416606A1 - Hydraulisches Hubgerät - Google Patents

Hydraulisches Hubgerät Download PDF

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Publication number
EP0416606A1
EP0416606A1 EP90117163A EP90117163A EP0416606A1 EP 0416606 A1 EP0416606 A1 EP 0416606A1 EP 90117163 A EP90117163 A EP 90117163A EP 90117163 A EP90117163 A EP 90117163A EP 0416606 A1 EP0416606 A1 EP 0416606A1
Authority
EP
European Patent Office
Prior art keywords
piston
pump
valve
lifting
cylinder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP90117163A
Other languages
German (de)
English (en)
French (fr)
Inventor
Wilhelm Lupold
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP0416606A1 publication Critical patent/EP0416606A1/de
Ceased legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47C—CHAIRS; SOFAS; BEDS
    • A47C3/00—Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats
    • A47C3/20—Chairs or stools with vertically-adjustable seats
    • A47C3/30—Chairs or stools with vertically-adjustable seats with vertically-acting fluid cylinder

Definitions

  • the invention relates to a hydraulic lifting device which, in particular for a chair with pedal-operated seat height adjustment, e.g. is intended for a barber or similar treatment chair.
  • the present invention is therefore based on the object to improve the hydraulic piston device of the type specified in the preamble of the main claim with regard to the valve unit and the piston brake in such a way that an undesired return of the piston, whether at the end of the pump stroke or after reaching the desired working position, is avoided becomes.
  • the units mentioned should be optimally combined with one another in a space-saving and cost-saving manner, it being ensured that the lifting and lowering movement and the clamping of the lifting piston are achieved with simple design means only by actuating the lifting lever.
  • valve unit is proposed according to the features of claim 1.
  • a separate spring is provided to generate the pressure point to be overcome, which acts on its own valve piston, which is to be actuated by means of the pump piston to initiate the lowering process.
  • the spring acting on the valve piston can be dimensioned independently of the spring acting on the valve ball.
  • the pressure prevailing in the lifting cylinder acts on this valve piston, which increases proportionally with the load acting on the lifting piston.
  • the force to be overcome at the end of the pump stroke to initiate the lowering movement increases with the load on the reciprocating piston, as a result of which the inadvertent initiation of the lowering movement of the loaded reciprocating piston, for example lowering the seat of a hairdresser's chair, on which a customer can take place what would turn out to be an uncomfortable shock, is prevented with greater certainty.
  • the mutually movable parts of the valve consist of a metal, in particular steel / plastic pairing, which ensures a better sealing function than with a steel / steel pairing even with hydraulic fluid contaminated by foreign bodies.
  • Claims 4 and 5 relate to the design of the piston brake, which additionally serves to secure the position of the piston.
  • the lifting piston is locked by means of an eccentric shaft actuated by the lifting lever, the eccentric of which is offset laterally to the axis of the lifting piston and acts on the lifting piston via a pressure piece.
  • This construction is relatively space-consuming and complex and, moreover, is difficult to readjust, but this is necessary in the event of wear.
  • the hydraulic lifting device shown is for a chair with pedal-operated seat height adjustment, e.g. for a barber chair, determined and suitable.
  • the load to be lifted e.g. the seat of the chair is connected to the piston 13 via the piston rod 13a.
  • the reciprocating piston 13 can be moved axially within the cylinder space 12 and is sealed with sealing rings 14 with respect to the reciprocating cylinder housing 10.
  • the lifting cylinder housing itself consists of an upper housing part 10 and a lower housing part 11 which is screwed into the upper one.
  • a cylinder liner 6 which is sealed off from the cylinder housing parts 10 and 11 by a sealing ring 7.
  • the pump unit To generate the hydraulic pressure, the pump unit is provided, the pump cylinder housing 30 of which is screwed into the valve housing 31.
  • the pump piston 32 which is sealed with respect to the pump cylinder housing 30 by a sealing ring 33, is mounted axially displaceably within the pump cylinder housing 30.
  • a helical spring 37 is provided, which is located at one end on an annular surface che 39 of the pump cylinder housing 30 and at the other end on a pressure plate 35 which is connected via a connecting ring 36 to the upper end of the pump piston 32.
  • a pressure arm 27 acts on the pump piston 32 and is connected to the two pump lever arms 20 and 21 (cf. also FIG. 3).
  • the pump lever arms 20 and 21, which are connected in a manner not shown to an actuation pedal, are, as is particularly clear from FIG. 3, pivotally mounted on the upper lifting cylinder housing part 10.
  • the pump lever arm 20 is firmly connected to a bearing pin 22 which is rotatably mounted in a pivot bearing 16.
  • the second pump lever arm 21, on the other hand, is connected to a clamping spindle 23, the right-hand thread 23a of which is rotatably inserted into the threaded bore 10a of the lifting cylinder housing part 10.
  • the clamping spindle 23 is moved radially inwards in the direction of the piston rod 13a and exerts a locking force on the latter via a pressure piece 24.
  • the clamping spindle 23 is firmly screwed to the pump lever arm 21 by means of a screw 25, a toothed disc 26, which is inserted between the end faces of the pump lever arm 21 and the clamping spindle 23, providing the required anti-rotation device.
  • the screw 25 can be loosened and the clamping spindle 24 rotated.
  • the reciprocating piston brake is to be set such that the piston rod 13 is blocked in the upper position of the pair of pump levers 20, 21, while when the hydraulics are actuated, that is to say when the pair of pump levers 20, 21 in the counterclockwise direction according to FIG. 1, the brake is released and the pistons 13 can be raised via the hydraulics.
  • the valve unit arranged in the path of the hydraulic medium line ensures the control of the hydraulic medium in the manner explained below.
  • the valve unit consists of a valve insert 40 which is inserted into the valve housing 31 and is axially fixed and sealed in this with a ring 48.
  • a sealing ring 49 seals the valve insert 40 from the inner wall of the valve housing 31.
  • a valve piston 42 is provided in a central bore of the valve insert 40 and can be axially displaced inward against the action of a prestressed compression spring 45.
  • the valve piston 42 consists of an upper cylindrical valve piston part 42e and a lower frustoconical valve piston part 42f. It has an axially extending through-bore 42a which widens in the lower area to form a valve ball housing 42g.
  • the transition between the bore 42a and the valve ball housing 42g forms a valve ball seat against which the valve ball 42b bears. It is under the action of a conical spring 44, which is supported on a support ring 50 at the other end.
  • a sealing ring 51 on the upper valve piston part 42 ensures liquid-tight guidance of the valve piston 42.
  • the valve insert 40 together with the inner wall of the valve housing 31, delimits a suction chamber 46 which is connected to the tank chamber 19 via a connecting bore 17 in the lifting cylinder housing 10 and a connecting tube 18.
  • a throttle bore 40c opens into this suction space 46, which bores with an annular space 40a in Neighboring the surface of the lower frustoconical valve piston part 42f is connected.
  • the suction space 46 is connected to the cylinder space 38 of the pump cylinder housing 30 via the connection bore 40d, the outlet opening of the connection bore 40d being normally closed by a liftable valve plate 41.
  • the surface 40b adjoining the annular space 40a of the valve insert 40 forms the valve seat for the valve piston 42.
  • the elements of the valve unit which are moved relative to one another consist of a plastic-metal pairing.
  • the valve insert 40 and the valve ball 43 are made of metal, namely steel, while the valve plate 41 and the valve piston 42 are made of plastic, e.g. Polyamide.
  • the valve unit is less sensitive to penetrating foreign bodies than a valve construction made entirely of steel.
  • the described lifting device works as follows:
  • the pair of pump levers 20, 21 is to be moved downward, that is to say against the direction of the arrow Z.
  • the pump piston 32 is moved down.
  • the piston 32 and with it the pair of pump levers 20, 21 are returned to their starting position.
  • the valve plate 41 is raised and the connecting hole 40d is released.
  • the hydraulic medium located in the tank chamber 19 is released via the connecting pipe 18, the connecting bore 17, the suction chamber 46 and finally Connection bore 40d sucked into the cylinder space 38 of the pump unit.
  • the valve plate 41 closes the connection bore 40d.
  • the hydraulic medium under pressure in the cylinder chamber 38 opens the ball valve with the valve ball 43 against the action of the conical spring 44, so that the hydraulic medium passes through the axially extending bore 42a of the valve piston 42 via the pressure chamber 47 of the valve unit into the cylinder chamber 12 of the lifting cylinder and the Piston 13 lifts.
  • the compression spring 45 acting on the valve piston 42 is dimensioned such that the valve piston 42 does not move during this pumping process and rests sealingly on the valve seat 40b.
  • the valve ball 43 closes the bore 42a under the action of the conical spring 44, so that the pressure chamber 47 remains closed until the next pump stroke or until the lowering process described below.
  • the pumping process can be repeated until the piston 13 has reached its uppermost position. As soon as the overflow bore 52 of piston 13 has reached the overflow 8, the hydraulic medium flows back into the tank space 19 via the overflow 8 and the return line 9. A further lifting of the piston 13 is prevented.
  • the piston is mechanically secured in the respective position, in particular against twisting, but also against inadvertent lowering.
  • the pump piston 32 To lower the reciprocating piston 13, the pump piston 32 is to be moved into its lowest position by means of the pair of pump levers 20, 21. In this he strikes the end of the valve piston 42 protruding into the cylinder space 38. The further downward movement of the pump piston 32 counteracts a precisely defined force, which is composed of the constant mechanical spring force of the compression spring 45 and a pressure force which is proportional to the system pressure prevailing in the pressure chamber 47 or in the cylinder chamber 12 connected to it. This force acts on the lower valve piston surface 42d facing the pressure chamber 47.
  • the effective counterforce derived from the system pressure results from the product of the system pressure prevailing in the pressure chamber 47 and the effective surface part of the lower valve piston surface 42d, which corresponds approximately to the effective surface of the annular space 40a.

Landscapes

  • Details Of Reciprocating Pumps (AREA)
  • Reciprocating Pumps (AREA)
EP90117163A 1989-09-08 1990-09-06 Hydraulisches Hubgerät Ceased EP0416606A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19893929851 DE3929851A1 (de) 1989-09-08 1989-09-08 Hydraulisches hubgeraet
DE3929851 1989-09-08

Publications (1)

Publication Number Publication Date
EP0416606A1 true EP0416606A1 (de) 1991-03-13

Family

ID=6388893

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90117163A Ceased EP0416606A1 (de) 1989-09-08 1990-09-06 Hydraulisches Hubgerät

Country Status (2)

Country Link
EP (1) EP0416606A1 (enrdf_load_stackoverflow)
DE (1) DE3929851A1 (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1707078A1 (en) * 2005-03-31 2006-10-04 Takara Belmont Corporation Hydraulic device for elevating/lowering chair
CN103982485A (zh) * 2014-06-04 2014-08-13 宁波科艺医疗器械有限公司 一种升降油缸

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE9321048U1 (de) * 1992-11-26 1995-11-16 Lupold, Wilhelm, 72189 Vöhringen Pumpen-Ventileinheit für einen Hydraulikzylinder

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3146592A (en) * 1959-05-20 1964-09-01 F & F Koenigkramer Company Hydraulic lift with rotation lock for beauty chair
US3763651A (en) * 1970-07-10 1973-10-09 M Okiyama Seat lifting device for use in barbers or beauty parlors and medical facilities
US3777617A (en) * 1970-12-14 1973-12-11 M Okiyama Automatic braking device for hydraulic pressure chair

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE7312079U (de) * 1973-09-27 Gebr Dickertmann Hebezeugfabrik Ag Druckmittel-Hebebock
DE1956722U (de) * 1966-11-10 1967-03-09 Luchtenberg K G Hagus Metallwa Wagenheber, insbesondere fuer kraftfahrzeuge.

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3146592A (en) * 1959-05-20 1964-09-01 F & F Koenigkramer Company Hydraulic lift with rotation lock for beauty chair
US3763651A (en) * 1970-07-10 1973-10-09 M Okiyama Seat lifting device for use in barbers or beauty parlors and medical facilities
US3777617A (en) * 1970-12-14 1973-12-11 M Okiyama Automatic braking device for hydraulic pressure chair

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1707078A1 (en) * 2005-03-31 2006-10-04 Takara Belmont Corporation Hydraulic device for elevating/lowering chair
US7281374B2 (en) 2005-03-31 2007-10-16 Takara Belmont Corporation Hydraulic device for elevating/lowering chair
CN103982485A (zh) * 2014-06-04 2014-08-13 宁波科艺医疗器械有限公司 一种升降油缸

Also Published As

Publication number Publication date
DE3929851C2 (enrdf_load_stackoverflow) 1993-04-01
DE3929851A1 (de) 1991-03-21

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