Seat of adjustable height having an adjustable back
United States Patent Scheben [4 Apr. 29, 1975 1541 SEAT OF ADJUSTABLE HEIGHT HAV]N(, 3368.845 2/1968 Watanabe 297/3311 AN ADJUSTABLE BACK jgowns ettali 1 i i, i:  
  A dUl&#39;Ll&#39;C 1 i t t 1 i i 4. s. [75] Inventor: Hans Schehen. K hl m-Ruhcn h. 3.71 171154 1/1973 Bauer 2411/400 Germany 3.756.654 9/1973 Bauer i i t 297/345 3.765.721] 10/1973 Sakai 297/330 1731 Assgflcei Kmlcm- Germlm) 3.817.575 6/1974 Bocksch ct a1. .1 297/355 [22] Filed: May 14, 1973 Primurr l:&#39;v\&#39;un11&#39;nc1-Rov D. Frazier 7 .4 App1&#39; 360988 .4ssis1unl E.\&#39;umimrWilliam E. Lyddane Attorney Age/11. or Firm-Hans Berman [30] Foreign Application Priority Data Ma 17. 1972 German 2223886 |57] ABSTRACT U s Cl 297/Hq 748/16, 248,400 A stool or like body supporting device having a seat 797/155 and a back. a first pneumatically expandable column I Int Cl 5 6 supporting the seat on a base, and a second such collg l Fie&#39;ld 3 154 umn holding the back in a desired angular relationship to the seat is equipped with a single operating lever 7 pivotally mounted on the seat for alternative engaget. ment with the release pins of the two columns so that 1561 References a user may adjust both the height of the seat and the FED STATES PATENTS slope of the back while manipulating the single lever. 3,137.71111 4/]964 Martens 297/355 x 3.33am: 8/1967 Kleinsorge a. 297/3311 Clmmm 8 Drawmg Flgures 1 2; m u t 1, e  
 SEAT ()F ADJUSTABLE HEIGHT HAVING AN ADJUSTABLE BACK This invention relates to a body supporting device having two columns of variable length operatively in terposed between a base and. respectively. a seat assembly and a back. and more particularly to an operating arrangement for controlling the length of the columns.  
  It is known to mount the seat of a stool, of a passenger car or utility vehicle. and like body-supporting devices on a pneumatic or hydropneumatic column of adjustable length which permits the height of the seat to be adjusted. It is also known to provide such a body supporting device with a tilting back whose angular position relative to the seat is maintained by means of a second column of the same type. A body of gas under pressure in each column tends to change the effective length of the column. and a control valve is provided to limit the biasing action of the gas. A releasing member outside the casing of the column is accessible for opening the normally closed control valve and for thereby changing the column length. A typical column of the type described has been disclosed in Axthammer US. Pat. No. 3.388.883.  
 In the known body-supporting devices which employ two such columns, separate operating elements are provided for the two columns and permit the seat height and the angle of the back to be adjusted to the shape and position of the supported body. For esthetic and other reasons. the two conventional operating elements are normally mounted out of the field of sight of a person whose body is supported on the seat. and it is inconvenient to grope for the two elements and to dis tinguish between them. An error in identification may have serious consequences if the drivers seat in a moving automotive vehicle is to be adjusted while the vehi cle moves.  
  It is the primary object of this invention to provide a body-supporting device of the type described in which the height ofthe seat and the angle ofthe back may be adjusted after manipulating a single operating member only.  
  With this object and others in view. the bodysupporting device of the invention comprises a base. a seat assembly. and a back connected to the base for pivoting movement relative to the seat assembly. The two longitudinally terminal portions ofa first column of variable length are respectively secured to the base and the seat assembly, and the corresponding portions of a second such column are respectively secured to the base and the back. Each column further includes yieldably resilient biasing means which bias the terminal portions to move longitudinally relative to each other, a control device normally limiting the biasing action of the biasing means. and a releasing member operatively connected to the control device and movable for inactivating the same and thereby releasing the biasing means. A single operating member is movably mounted on the base for alternative engagement with each of the two releasing members and for thereby moving the en gaged releasing member to inactivate the associated control device.  
  Other features. additional objects. and many of the attendant advantages of this invention will become better understood from the following detailed description ofa preferred embodiment when considered in connection with the appended drawing in which:  
  FIG. I is a fragmentary. side-elevational, and partly sectional view of a body supporting device of the inven tion;  
  FIG. 2 shows the device ofFIG. I in fragmentary plan section on the line [I II;  
  FIGS. 3 to 5 respectively illustrate the apparatus of FIG. 2 in fragmentary sections on the lines I III. IV IV. and V V:  
  FIG. 6 shows an element of the device in rear elevation;  
  FIG. 7 shows the element of FIG. 7 in side elevation; and  
  FIG. 8 shows a portion of the body supporting device largely omitted from FIG. I in elevational section.  
  Referring now to the drawing in detail. and initially to FIG. I, there is shown only as much of a stool of the invention as is needed for an understanding of the invention. Only the top portion of the upright. tubular base 13;; of the stool is visible in FIG. 1. The cylinder 13a of a first pneumatic. expandable column l3 movably projects upward from the base 13g and is connected to the supporting frame 40 of a seat cushion I4 by a coaxial extension tube 1. A single operating lever 4 projects outward of the tube I in a generally radial direction between two mounting brackets 20,29, and is astened to the brackets by a pivot pin 5 for angular movement in a plane which includes the common vertical axis of the tube I. the cylinder 13a. and the base 13g.  
  A bracket 44 is pivotally attached to the seat frame 40 by a pivot pin 44a remote from the tube 1. and the back 43 of the stool is fixedly attached to the bracket 44, and thereby pivotally secured to the base 13g. A second bracket. identical with the bracket 44, is obscured in the drawing. and also attached to the frame 40 by the pin 44a. A pin 4] connecting respective parts of the two brackets provides a pivot for an eye 42 at the axial end of an approximately horizontal cylinder 15a of a second pneumatic, expandable column IS. The piston rod 33 of the column 15 is hingedly attached to a fork 30 radially projecting from the tube 1, as will presently be described in more detail.  
  As is conventional in itself. the piston rod 33 carries a piston [5b in the cavity of the cylinder 15a and nor mally separates two axial compartments of the cavity. An axial bore 15c in the piston 15b connects the two compartments when a normally closed control valve 15d in the bore is opened by means ofa linkage 15c extending in the piston 15b and the tubular piston rod 33 toward the tube 1, as shown in more detail in FIG. 2 of the afore-mentioned patent.  
  As is seen in FIG. 2. the outer end of the piston rod 33 is externally threaded, and a pivot head 9 is threadedly fastened on the rod 33 and secured in position by a locking nut 39. The linkage l5e, not otherwise seen in FIG. 2. terminates in a releasing pin 12 longitudinally movable in the rod 33 and carrying a spherically arcuate head or button. The pin 12 is obscured in FIG. I by the fork 30.  
  The tube I has three openings 24,2526 in the common radial plane of FIG. 2. The openings 24.25 are diametrically opposite each other. and the opening 26 is angularly equidistant from the other two openings. The aforementioned brackets 20.29 are respective straight. parallel end portions of two flat bars 3.6 which pass through the opening 24 together with the lever 4. They are secured to each other and to the lever 4 by the aforementioned pin 5 and a retaining ring 2 on the pin. The circumferential width ofthe opening 24 is only suf ficiently greater than the combined corresponding dimensions of the bars 3,6 and the lever 4 to permit the angular movement of the latter.  
  The other end portion 45 of the bar 3 and the end portion 19 of a flat bar 8 are jointly received in the opening in conforming engagement with the walls of the opening. An intermediate portion 46 of the bar 3 is laterally offset from the end portions 29,45 for partial conforming engagement with the cylindrieally concave inner wall of the tube 1 and for thus longitudinally securing the bar 3.  
  The bars 6 and 8 ha\e each two leg portions offset at right angles to each other. The leg portion 23 of the bar 6 and the leg portion 21 of the bar 8 pass in spaced, paraliel alignment outward through the opening 26 in the tube 1. and their free ends. offset away from each other jointly constitute the fork 30. Each of the free ends has a longitudinally open, longitudinal slot 31 whose inner end 32 is cylindrically enlarged. Integral pins 34 on the pivot head 9 are received in the enlarged slot portions 32, thereby pivotally connecting the rod 33 to the tube 1 and to the base 13g. A a motion transmitting push rod 7 passes through the opening 26 between the leg portions 21.23 with minimal circumferential clearance. A cam face ll on the lever 4 in the tube I cooperates with the push rod 7 in a manner presently to be explained.  
  As is shown in FIG. 8. the Cylinder 13a encloses an axially movable piston 13b from which a piston rod 13c passes axially downward through the bottom wall of the cylinder 130 into abutting engagement with the bottom wall of the generally cup-shaped base 13g. A conduit 13f is permanently open toward the compartment in the cavity of the cylinder I below the piston 13b, and has an orifice toward the upper cylinder compartment which is normally closed by another control valve [3e biased toward the closed position by a non-illustrated spring. A valve stem or releasing pin 17 passes upward from the valve 130 and axially out of the cylinder 13a in sealing engagement with the latter. The upper end portion of the cylinder 13a is provided with external threads I311 for engagement with mating threads of the tube l.  
  The two compartments of the cylinder [3a are filled with compressed air which may hold the piston 13b in a position in which the forces of the gas acting on the two radial piston faces balance each other. When the valve 131 is opened, the connected gas portions act as yieldably resilient biasing means which tend to expel the piston rod 131&#39; from the cylinder, and to increase the overall length of the column I3 by driving the cylinder I311 outward of the base 13g unless the gas pressure is overcome by a stronger external force driving the piston [31&#39; inward of the cylinder, and the cylinder inward of the base 13g.  
  The combined weight of the seat frame 40 and, of portions of the stool attached to the frame 40 is insuffient to overcome the internal gas pressure in the cylinder 130. When the valve [3e is opened by depressing the pin [7. the column 13 expands, and the seat cushion 14 is raised. The dimensions of the column [3 and the gas pressure are selected so that the weight of any adult seated on the cushion 14 can shorten the column I3 when the valve l3e is opened. Then the valve is closed, the biasing action of the gas in the cylinder 13a is limited to resilient response to the applied load. The full biasing action of the gas is released by the control valve when the pin 17, acting as a releasing member. displaces the valve from the illustrated position.  
  The column 15 interposed between the seat back 43 and the tube 1 operates in the same manner. When the releasing pin [2 is pushed inward of the piston rod 33, the control valve 15a is opened, the biasing action of the gas in the cylinder [5a no longer is limited by the inactivated valve, and the back 43 is tilted clockwise, as viewed in FIG. 1, by the expanding column 15 unless the occupant of the seat pushes the back toward the position shown in broken lines while the valve [Se] is open.  
  The portion of the pin 17 projecting from the column 13 is in the path of pivoting movement of the operating lever 4 in the tube 1, as best seen in FIG. 3. When the outer end of the lever 4, not itself seen in FIG. 4, is lifted, the pin 17 opens the valve [32, and the seat frame 40 together with associated elements is raised unless sufficient opposite forces cause a shortening of the column.  
  Referring to FIGS. 5 and 6, it is seen that the push rod 7 has a longitudinal groove 18 which is guidingly engaged by a guide rib 22 of the leg portion 21. The part of the push rod 7 normally received in the tube 1 is axially wider than the leg portions 21,23, and the opening 26 of the tube I is shaped and dimensioned to confine the leg portions 21,23 and the enlarged part of the push rod 7 with just enough clearance to permit longitudinal movement of the rod 7. The inner end of the rod has an oblique cam face 16 located for cooperation with the cam face 11 ofthe lever 4 in such a manner that the rod 7, guided by the rib 22 and the walls of the opening 26 in a direction which has at least a major component axial relative to the cylinder 15a, is moved longitudinally outward of the opening 26 when the outer free end ofthe operating lever 4 is depressed. A concave abutment face 38 on the outer end of the rod 7 engages the head of the pin 12 under the pressure of a non-illustrated return spring acting on the valve 15d. The rod 7 thus transmits the motion of the lever 4 to the pin 12 and causes the valve 15d to be opened so that the angular position of the back 43 may be changed.  
  The assembly of the control mechanism for the illustrated stool is facilitated by the configuration of the integral pins 34 on the pivot head 9. As is best seen in FIGS. 6 and 7, the pins are of oblong cross section, having two flat long faces 35 connected by shorter convex faces. The width of the pins between the faces 35 is small enough to permit the pins 34 to be moved into the slots 3] in a position in which the threaded bore 47 of the head 9 is perpendicular to its position illustrated in FIG. 4. After the pins 34 enter the enlarged slot portions 32. the pivot head may be turned into its normal operating position, and may then be assembled with the piston rod 33 and the nut 39.  
  It will be appreciated that the bars 3,6,8 are to be assembled with the tube 1, to be followed by the lever 4 and the rod 7. before the pivot head 9 is installed and connected with the column 15. The sequence in which other elements ofthe stool are assembled is too obvious to require more detailed description.  
  While the back 43 and the lever 4 are mounted on the seat assembly constituted by the tube 1, the frame 40 and the cushion l4, and are connected to the base 13g by the seat assembly and the first column 13., the advantages of the invention are also available in devices in which the back and the operating lever are connected to the base 13g in any other manner. and the connection between the second column 15 and the base may have to be modified accordingly.  
  The disclosed columns 13,15 are preferred in a stool of the type disclosed, but neither their orientation nor their specific details are critical for achieving the desired simple and foolproof inactivation of their respective control valves l3e.l5d. Either column may be inverted so that the cylinder 13a and the piston rod 33 are near each other. The cylinders of both columns may be near the tube 1. or the cylinders may both be remote from the tube 1. as is the cylinder lSa in the illustrative embodiment. The necessary changes in the valve arrangements will be obvious. Valve arrangements other than those specifically disclosed. but known in this art. may be substituted for the valve arrangements illustrated and described.  
  It should be understood. therefore. that the foregoing disclosure relates only to a preferred embodiment of the invention. and that it is intended to cover all changes and modifications ofthe example of the invention herein chosen for the purpose of the disclosure which do not constitute departures from the spirit and scope of the appended claims.  
 What is claimed is:  
  l. A body supporting device comprising. in combina tion:  
 a. a base;  
 b. a seat assembly;  
 c. a first column of variable length including 1. two longitudinally terminal portions respectively secured to said base and said seat assembly.  
 2. yieldably resilient first biasing means biasing said terminal portions to move relative to each other in a predetermined longitudinal direction.  
 3. first control means normally limiting the biasing action of said biasing means. and  
 4. first releasing means operatively connected to said control means and movable for inactivating said control means and thereby releasing said biasing means;  
 d. a back connected to said base for pivoting movement relative to said seat assembly;  
 e. a second column of variable length including 1. two longitudinally terminal portions respectively secured to said base and to said back.  
 2. yieldably resilient second biasing means biasing said terminal portions of said second column to move relative to each other in a predetermined longitudinal direction and for thereby pivoting said back.  
 3. second control means normally limiting the biasing action of said second biasing means. and  
 4. second releasing means operatively connected to said second control means and movable for inactivating said second control means and thereby releasing said second biasing means;  
 f. a single operating member; and  
 g. mounting means movably mounting said operating member on said base for alternative engagement with said first and second releasing means and for thereby moving the engaged releasing means to inactivate the associated control means.  
  2. A device as set forth in claim I. wherein each of said first and second releasing means includes a releasing member mounted on one of the two terminal portions of the associated column. the other terminal portion of said associated column being spaced from said releasing member in a direction away from the other column.  
  3. A device as set forth in claim 2. wherein each col umn includes an elongated cylinder having a longitudinal axis. and a piston rod axially projecting from said cylinder. respective axial end portions of said piston rod and of said cylinder constituting said longitudinally terminal portionsv 4. A device as set forth in claim 3. wherein said seat assembly is mounted on the terminal portion of said first column carrying the releasing member of said first column. the terminal portion of said second column carrying the releasing member of said first column being secured to said seat assembly.  
  5. A device as set forth in claim 4, wherein the axes of the cylinders in said columns are approximately perpendicular to each other.  
  6. A device as set forth in claim 4, wherein said operating member is movably mounted on said seat assembly. said seat assembly and said first column constituting elements of said mounting means.  
  7. A device as set forth in claim 6. wherein said mounting means further include a pivot securing said operating member to said seat assembly for angular movement from an inoperative position in two opposite directions. said operating member during movement in said opposite directions respectively engaging said releasing means of said first and second column.  
  8. A device as set forth in claim 7. wherein the releas ing means of one of said columns include a motion transmitting member operatively interposed between the releasing member of said one column and said op erating member. said motion transmitting member and said operating member having respective cam faces engaging each other during said angular movement of the operating member in one of said opposite directions.  
  9. A device as set forth in claim 8, further comprising guide means on said seat assembly guiding said motion transmitting member in a direction having a major component axial relative to the cylinder of said one column.  
  10. A device as set forth in claim 2, said mounting means securing said operating member for angular movement from an inoperative position in two opposite directions. said operating member during angular movement from said inoperative position in one direction engaging the releasing member of one of said first and second releasing means. the other one of said first and second releasing means including a motion transmitting member operatively interposed between said operating member and the releasing member of the other releasing means for movement in a direction toward and away from said releasing member of the other releasing means. said operating member during angular movement from said inoperative position in the other direction engaging said motion transmitting member and moving the motion transmitting member toward said releasing member.