US 2522246 A
Description (OCR text may contain errors)
Sept. 12, 1950 A. D. ARMSTRONG RECLINING CHAIR Fila Aug. 28, 1945 4 Sheets-Sheet l Ae w/e QAZ/w wA/a INVENTOR.
7/77'OP/Yf) Sept. 12, 1950 A. D. ARMSTRONG 2,522,246
RECLINING CHAIR Filed Aug. 28, 1945 4 SheetS-Sheet 2 IN V EN TOR.
4rroe/vi/ A. D. ARMSTRONG Sept. 12, 1950 RECLINING CHAIR 4 Sheets-Sheet 5 Filed Aug. 28, 1945 6 m 2 v M 4 w w 2 A Sept. 1950 A. D. ARMSTRONG I 2,522,246
RECLINING CHAIR Filed Aug. 28, 1945. 4 Sheets-Sheet 4 Ed MW Arrow f) Patented Sept. 12, 1950 RECLINING cn'Am Arthur D. Armstrong, Los Angeles, -Calif., assignor of one-half to Percy ;L. Porter, Los Angeles,
Application August 28, 1945, Serial No. 613,040
12 Claims. I 1
This invention relates to adjustable chairs, and more particularly to such a chair having means for locking the chair in any desired position of adjustment.
Adjustable chairs provided with means for locking the same in some positions of adjustment, have been heretofore proposed. These prior chairs were objectionable for a number of reasons. The principal objection to the chairs previously proposed was that the locking devices did not lock the chairs in any desired position of adjustment, but merely in one of a plurality of positions. I
, The locking devices of prior chairs generally consisted of a plurality of detents carried by one movable element of the chair and a dog or the like formed on another element, which when engaged in any one of the detents held the two elements against relative movement. The positions of adjustment of the chair were fixed by the relative disposition of the detents, and oftentimes a user found that the more comfortable position of the chair was one in which the dog was disposed between two adjacent detents and the chair could not be locked in the position desired. In such cases the user was forced to adjust the chair until the dog engaged one or the other of the two adjacent detents.
Attempts to remedy this defect were made by increasing the number of detents, but little success was had as it was found that if the number of detents was increased and more closely spaced, the lock did not have the strength sufficient to withstand the stresses set up therein in use. This was particularly true where the chairs were used in railway cars, buses, and aircraft where changes in acceleration or momentum of the vehicle caused high transient stresses in the lock. Efforts to obviate these diificulties by proposing frictional locks were also unsuccessful,
as it was found that the service life of such locks was quite short, and the locking action was'not suliiciently positive to warrant their use in public conveyances.
The present invention obviates the difiiculties had with prior locking devices as adjustable body supporting members of the chair of the present invention will remain in any adjusted position desired. The locking device of the chair herein shown is positive in action and will take even those abnormally high transient loads to which chairs are subjected in railway cars, buses, aircraft and like public conveyances.
In one embodiment of the chair of the present invention, a seatrest is pivotally connected at the lower end thereof to a back rest for supporting the back of the user. The back rest is pivotally carried by a suitable frame to be fixed to a support such as the floor and as the front edge of the seat rest is supported for movement longitudinally of the same, the relative position of the seat and back rest can be adjusted.
In another embodiment of the chair of the present invention, the seat rest is fixed against .movement longitudinally of the chair While the back rest is supported for pivotal movement. As one body supporting member is movable the relative positions of the body supporting members. can be adjusted to accommodate different users.
The locking device of the chair of the present invention comprises a hydraulic cylinder and a piston operating therein connected respectively to @relatively movable elements of the chair. The cylinder is provided with a passage extending from one end of the same to the other in which is mounted a manually controllable valve. The passage forms a bypass around the piston ofthe locking device so that when the valve is open the seat and back rest may move relative to each other, the fluid in the cylinder being forced by movement of the piston from the cylinder on one side of the piston through the bypass passage and back to the cylinder on the other side of the piston.
The valve in the bypass passage is normally held closed but may be opened by the user througha suitable mechanism having an operator located on a portion of the chair convenient to the user. As the fluid filling the cylinder is non-compressible, the chair will be locked against movement as long as the valve is closed. and the chair will be held in any desired position.
To permit an adjustment of the chair it is only necessary to operate the valve controlling mechanism to open the valve, after which the chair may be adjusted by merely applying forces to a movable element of the chair.
, In one embodiment of the present invention the cylinder is supported by the frame of the chair and the end of the rod of the piston is pivotally connected to the seat rest. As the seat rest is held against movement relative to the frame by the cylinder and piston, the back rest cannot be moved and consequently the chair will be securely locked against accidental movement from a desired adjusted position.-
In another embodiment of the invention herein disclosed, the cylinder is carried by the seat rest and the piston rod connected to the back rest. Thus as two relatively movable body supporting members of the chair are interconnected by the cylinder and piston no accidental relative movement can occur as long as the valve controlling the flow of fluid through the bypass is closed. 1
In the embodiments of the presentinvention herein shown, the valve is normally held closed by a spring and is so constructed and arranged that any force tending to recline the chair causes the fluid of the cylinder to augment the normal action of the spring. The valve, however, will open against the action of'the sprin'gif *a'relatively large force is exerted against the back rest in the direction necessary to move the fcha'ir to an upright position. Thus a user or an attendant, if the chair is used in a public conveyance, can move the chair to an upright position without the necessity of opening the valve by znere'ly urging the E back r rest 1 to '1 the: uprightposition.
*Qtherife'atures and advantages of the present invention :will :be ap arent from the following description-taken in connection with the accompanying drawings, llll which:
Figure 11 iis La perspective :view from below of one f ormof i the chair' of the present invention with certain partsnnsection -and certain parts broken: away to more clearly: illustrate the lockin'g device of the -chair with 'parts of the leeking device shnwnin phantom;
ffiigure .2 '-is anielevational view of the form of'lth'e chair-showniniFigui-e1 with certain parts in sectioneandficertain parts lbroken away-to more clearly illustrate the invention;
AFigureSAsatvieW partly in section-and partly in 'Jelevati'onof thelloc'king device -of the chair of the present invention;
Figure i l is' a sectional view taken along line M l-ref Eigu'refi;
iFi'gure ris a. sectional -view=of afragm'entary part :of the lockingcdevice of the present inverition;
. Figurezd is a viovwsimilar to Figurefi-but showinga :modifiedio'rnm of the chair of the present invention ;:and
Figure isia'n'other view-similar 'to Figure 2 but showing a-i still further modified form'of the cliair of the-present invention.
The chair of the present invention, "referring now'to thedrawing, and particularly to Figure l 1 thereof, comprises a frame i I 0, formed of side inen'ibers l l rigidly interconnected by cross members l 2. Each si'de member "ll terminates ina pair-ofsuppcrting legs l3 whichmay be provided' with some means not shown for securing thesame to the floor'or other-supporting structure.
The front cross member I2 carries a pair of substantially L-shap'ed brackets M, and in'the preferred formof the present invention the "one arm "of ea'ch'bracket is sli'dably-mounted in an aperture 'formed inthe-cross member l2. The lower end of this is formed with a head [5 on which seats a large washer '16 forming a shoulder for receiving a coiled spring '11. The springsurrounds the portion of thearm extending through the'aperture 'an'dacts agains'tthe underneath surface of the front crossmember II to normally urge the washer and the arm carrying the same-downwardly; as viewed in Figure2.
The other armof the bracketzextends'forwardly of the aperture and carries "intermediate the ends, thereof a roller l8 which is resiliently held down by the spring I! against the upper surface of the front cross member. A larger roller I9 is rotatably mounted to the end of each of the arms carried above the front cross member, and serves to slidably support a seat member 2|. The frame 22 of the seat member 2| is formed ton the underneath :surface thereof with a'pair of spaced parallel'tracks 23 for operating over the larger rollers l9.
The rear edge portion of the seat frame 22 is (provided with a pair of ears 24 at the opposite sides thereof to which are pivotally connected. respectively, -spaced 1'ugs 25 formed at opposite "sideso'f the'lowerrportion of a back rest frame 26. The ears in'aybe pivotally connected to the flugsvfifbyw-anylmeans desired, such as a suitable pivot pin.
Ri'g'idly-secured to opposite sides of the back rest frame 26, intermediate the ends thereof, are a -pair of brackets 2 1, each-carrying a-suitable pin' i fl for pivotally mounting the 'back restfrarn'e between' the upper p'ortionsof the side member ll of the frame I0. As showng'the pins1Z8 are mounted in brackets 29 carried-by the "side: members H.
It-will'now 'be: seen -that as the'seatis 'pivotally connected to I the back rest, "which in "turn is pivotally carried by-the 'sidemembers H, movement of'the seat -over -'the 'rollers l9 will bring about a pivotal movementof theb'ackrest'. Thus it will be --seen that :the -"relative position-of' the seat and the back rest can be adjusted "by a user merely by shifting-the position of the seat relativeto theframe.
"The side members I l 0f the-frame "l U"carry suitable armq'ests 3 I which may be padded and covered with any material desired, depending upon -theuseto *which the chair is=to be put. Itshould be understood how that the seat member 2l,=as well asthebak-rest, is also padded and upholstered with some material suitable for a'c'overing in the intended use of the chair.
To hold or lock the body :supporting "members-in"any=desired position-of adjustment, the present invention-provides a hydraulic locking element which i-n one illustrative embodiment 'of the invention comprises a 'fluid fil-ledcylinder "34 pivotally connected to the frame l0, and a'piston 35 connected'throu'gh a-rodand a pivotal conmotion to the =frarne 22 of the seat '1 I. "In the form of the invention illustrated, the *piston' 35 comprises arr-annular member'fixed in any manner desired. to -an-elong-ate rod 35 'intermdia'te the'ends'ther'eof. "Thepi'ston is formed'with a circumferential groovewhi'ch'carries an O-ring 31"to effectively seal the sliding seat between the wall of the cylinder andthepiston. The rod Sis-extends outwardly ofboth ends of the cylin'der which-are-sea1ed againstieakage by'sealed bearings '38. The one-end of the piston rod '36 carriesa connection m'ember' 39 formed with an eyefor freely-'receivin'g'a headed'p'in" 40 adapted to be-passed through alignedapertures in an eared bracket 4| rigidly fixed'tothe frame 22 of the seat 2|. The"pin 4fl -is held against removal from the "bracket by 'any conventional means such as pe'ening the projecting end :of the-same.
The cylinder"housing'carries at the one end thereof-a mountinf fixture 52. The fixture-can be secured-to the cylin'der housing in any mannerdesired=as longas the fixture-is free to-rotate or rock relative to the housing. In the form of the invention illustrated the housing is proyid d witlpa pair Of.:.-oppositely directed pins 43 for reception in aligned openings formed in the fixture. The outenends of the pins are formed with circumferential grooves for anchoring re- The cylinder is completely filled with somesuitable fluid which is non-compressible, and it willbe seen that as the cylinder is connected to the cross member of the frame ill, and the rod 36 f the piston 35 to the frame 22 of the seat member, no relative movement of the seat and back rest can occur.
To v permit conjoint movement of the body supportingmembers; means are provided in the present invention forby p-assing the piston 35 so that the same can be moved relative to the cylinder Although any means desired can be provided for by-passing the piston, in the form of the invention illustrated; this means comprises a passageway 44 extending substantially the length of the cylindrical-housing, and communicating with the cylinder through'ports 45 and 46. The port 45 is formed-in an enlarged portion of the cylinder housingand-i-ts course extends outwardly from the cylinder and then leads to the one end of the same. The purpose. of this construction will be hereinafter more fully explained. The ports 45 and. 45, as wellas the passageway .44, are filled with the liquidof the cylinder.
As the ports lead from the passageway 44 to opposite ends of the cylinder theliquid may pass from the cylinder through one port into the passageway and then return through the other of the ports to the cylinder. It will thus be seen that as long as fluid may pass through the one port and passageway and return to the cylinder through the other of the ports, the piston is free to move relative to the cylinder. I
To prevent the flow of liquid except when it is desiredfltoz adjust the relative position ofthe seat and back rest of the chair, a valve is interposed intermediate the ends of the port 45. The valve, as best seen in Figures 3 and 5, comprises a ball 48 normally held by a spring 49 on a spherical seatl. The spring, disposed in the enlarged portionof the housing, is retained in resilient engagement with the ball 48 by means of a small plate 52 fixed to the side wall of the cylindrical housing.
To open the valve and to cause the ball 48 to move upwardly of its seat against the action of the spring 49, a small shaft 53 is rotatably mounted within the cylinder housing. The shaft is formed with a cut-away portion having a cylindrical surface 54, the major axis of which is displaced from the axis of the shaft. so that when the surface54 is engaged by a second ball 55, the ball 48 is held on the seat 5|. When the shaft 53, however, i rotated to move the surface 54 out of engagement with the ball 55, thecam formed by the cylindrical surface of the shaft 53 cams the ball 55 upwardly, as viewed in Figure 5, and forces the ball '48 from its seat 5i. Fluid is now free to pass from the one end of the cylinder through the port 45 into the passageway 44 or from the other end of the cylinder into the passageway 44 through the port 46. As the liquid of the cylinder can be thus displaced, the piston can move relatively to the cylinder and the \chair adjusted. I H
,An operating arm 56 i fixed to one end of the I vention illustrated in Figuresl and 2, the mountlever 56 and at the other end to the front cross member l2 of the frame I0.
, So that an occupant of the chair may conveniently manipulate the operating arm 55, a
flexible-cable 58 has one, end thereof fixed to the .Loperating arm 55- and the other end is passed over: the pulleys 59, .60 and 6! and secured to a ffinger. 52 carried by a push-rod 63 mounted in clcsedho relative movement can occur between one arm rest of the chair for reciprocal movement. fI'hepush-rod is journaled in the arm rest andone side member ll of the frame ill of the chair by bearing members 64 and 65, respectively.
The outer end of' the push rod 63 is formed with an operating button 56, which is normally held substantiallyflush with the front surface of the arm rest by a spring G'l, coiled about the front end of the push-rod- 63 and disposed between the operating knob 55 and a bracket 68 which carries engagement with the ball 55. As heretofore ex plained, this movement of the shaft cams the ball 55 upwardly to force the ball 48 off its seat 5!. As soon as theball 53 is forced off its seat,
the piston is free to move longitudinally of the cylinder, and the seat and back rest arerelased for conjoint movement to any desired position of adjustment. After the seat and back rest have been moved to the particular position of adjustmentdesired by the occupant, the operatingflknob 55 is released, whereupon the spring BTQI'E'filllhS the push-rod to its normal position and thespring 5'7 returns the operating lever 56 to the'position in which the surface 54 of theshart 53 is again engaging the ball 55. The
spring 45 is now free to move the ball 48 back the piston 'andthe cylinder. The movement elements of the chair are now locked against move- I'nent.
It will be seen, referring now to Figure 5, that "any movement of the piston rod to the left, as view ed in the figure referred to, will cause the liquid in the port 45 to more tightl force the ball ili'ag'ainstthe seat 5| and thereby augment the action of the spring 49. The cylinder is connected to'the chair to take advantage of this feature and aurore'es exerted against the back rest whieh tend to move the same toward the re cliriedpdsition will cause the ball to more tightly engageits seat.
It should be seen, however, that if sufiicient pressurefis'created on the underside of the ball 4B,las'viewed in Figure 5, the ball can be forced off the seat without rotation of the shaft 53. This is a feature of the lock of the chair of the presentinvention for the chair can thus be moved "from a reclining to an erect position without first opening the'by-pass valve. This feature of the chair is particularly important where the chair is used in a public conveyance such as an aircraft orthe like for a stewardess or other attend-ant I can move all chairs in the airplane to a uniform erect position merely by urging the seat rest to an pright position. The force necessary to urge thebal1-48 off its seatiisfrelativelyllarg'e butlit will be tnoted that "the force :applied to the top edge ofthe back restlisima'gnifie d by the lever arm formed by'the pivotally'mounted backrest so that a relative small force will create the pressure in liquid .necessary 'tOurge the aball ofi its seat.
lItshould be understood now ithat'ithedockih device of "the chair of thezpresentsinvention will actually hold the body supportingmembers of thechair 'in any position oftadjustm'erit desired. The positions of adjustment. are infinitesimal'and are not limite'dto any mechanical spacing of ele- =ments of:thelocking.device as in the prior:pr-oposed chairs. The locking device of thepresent invention is positive in :action but yet can 'be easily released when it is desired 'to adjust the relativeposition of the seat-and baokmemberof the chair.
The chair of the :present invention :is much easier to 1 adjust :than chairs heretofore .l proposed and supplied with some "mechanical locking imeans, for there is considerablylessfriction between thecylinder andpiston than there is-between the movable elements ofthe priormechanical locks.
Inthe embodiment of the invention illustrated inFigures 1-and'2, the cylinderhasibeenlshown secured to thefrontrcross-member of the-chair,
and the piston rod pivotally fixed by means of member. It is obvious that this relationship could be reversed and-the same desirable'results obtained,.-for in the-broadest aspectsof the.present invention .it is. merely necessary that-the hydraulic locking device interconnect tworelatively movable body supporting-members .or the chair. In the embodiment of theinventionshown in .Figure 6, the chair illustrated .is substantially identical with the. chair heretofore..described, and the-same reference characters-havebeen applied to elements common inlboth chairs. .Inthis form of the invention, the cylinder ispivotally mounted to the frame "22 of theseat member 21 an'dlthe ,piston rodlis secured to-an extensionmember carried by the back rest frame-H. 'The; pi'ston rod in this embodiment of the inventioncan'be formed with abifurcate'd connectionmember .12 having a pair of aligned aperturesiormed therein for receiving oppositely directed pins Iii-carried by 'the extension member 'lU ofthe back rest frame 'H.
It should be understood that the cylinder and piston of the chair illustratedin Figure 6 'hold the body supporting members against relative.
movement asinthe earlier'described' form ofthe chair, and that the opening of the valvenormally closing the by-passconduit permitsitlie seatlmemher and back "restto be relatively adjusted.
In the form of the'chair of the'present invention Carried y ajour'nal bracket 85 fixed to'eachsid'e member I I.
"Tlie'backu'estframe B2 is formed at the lower "edge "thereof with a downwardly extending farm si'intermediate the "opposite side edges thereof. 'The'arm carries aipint'l 'and'the opposite ends "ofthisjpin are held in aligned"aperturesformed in'a bifurcated connection member 88 carried by the angle member Al to theframe 22 of theseat thcepiston rod 3th of theihydraulic unit heretofore described.
The cylinder and pistonas long as the'by-pass is closedbythe occupant-operated valve as in the earlier described forms of 'theinvention holds the body-supporting members of 'the chairagainst relative movement but yet permits 'rea'dy adjustinerit as'soon as the valve is opened to, permitioil to flow through the .by-pass conduit.
.In this'embodirnent ofthe chair .of'the present invention, a coil spring '89 J sleeving the-piston. rod. '36 'isinterposed between 'the'one endo'f the cyl- .inder'tt andthe arm86. It will'be seen-that the spring89 normally tends to urge the'back rest frame '82 to an upright position such as 'illustrated in Figure 7. Thus a steward .Orother-attendant .of a public .conveyance equipped with chairs of this embodiment of the present. inventicncan .by merely actuating .the button 6B of .each chair cause all chairs to assume identical .positionswith the backrests in an uprightposition such as illustrated in the figure referred 'to above.
It-willnowbe seen that'in all illustrated embodimentsof the present invention-the body supporting members of the chair herein disclosed can be held in any relative position of adjustiinent desired. Thezpositions' of adjustment of the chair are :in "no way limited by the lockingtdevice of the chair yet the locking device is positive in action and readily released'when it is desired to adjust thebody'supporting members of the chair.
Although the 'now preferred embodiments of "the present invention have beenshown and described herein, it isto be'understood thatthe inventionis not to be limited thereto,for it is sus- -ceptibleto changes'inform and detail within the scope of the appended claims.
1. In an adjustable'chair of the type described, a frame; a seat member slidably'mounted thereon; a backrest pivotally supported by said-"frame; means for pivotally interconnecting said seat member and back rest for conjoint movement; a cylinder; apiston operating in said cylinder, said cylinder and piston interconnecting two relatively movable elements of said 'chairpsaid cylinder being completely filled with a non-compressible fiuidwhereby said seat member and backrest are' hld' against movement relative to said frame means for conducting'the fiuid'held "bysaid cylinder from one end thereof to the'other so that-sai'd piston-may move relative to said :cylinder when an occupant of. said'chair desires to change the'relative position of said backrest and seat member; 'an'dmeans operable by said "occupant-for controlling said last-named means.
2. An-adjustable-chair-of the type described l comprising a frame; a seat member mounted on last-named means including means on said frame and convenient to an occupant of the chair.
3. An adjustable chair of the type described said frame; means for pivotally connecting said seat member to said back rest so that movement of said seat member causes movement of said back rest; a cylinder; a piston operating in said,
members of said chair; a non-compressible fluid completely filling said cylinder and holding said piston against movement therein; and means controlled by the occupant of said chair for bypassing'the fluid around said piston whereby said j rest and the frame of said ch air, said cylinder being completely filled with "a non-compressible fluid whereby said back rest may be held against movement relative to said frame; a bypass means around said piston; means normally closing said bypass means; and means, including, means mounted on said chair convenient to the occupant thereof and adapted to be operated by said occupant, for rendering said last-named means inoperative so that said piston may move relative to said cylinder to permit the occupant to change the angular position of said back rest relative to said seat member.
5. In an adjustable chair of the type described, a frame; a seat member mounted thereon; a back rest; means for pivotally mounting said back rest to said frame for movement relative to said frame and seat member; a liquid filled cylinder; a piston operating in said cylinder, said cylinder and piston interconnecting and holding said seat member and back rest against relative movement; a bypass interconnecting opposite ends of said cylinder whereby the liquid of the cylinder may flow from one side of said piston to the other when the occupant of said chair desires to change the relative position of said seat member and back rest and a force is applied to said piston; and means under the control of said occupant for closing said bypass to hold said piston against movement relative to said cylinder and lock said back rest in a desired position of adjustment relative to said seat member.
6. In an adjustable chair of the type described, a frame; a seat member; a back rest; means for pivotally interconnecting said seat and back rest to said frame for relative movement; means including a liquid filled cylinder and piston operating in said cylinder, said cylinder and piston interconnecting and holding said seat and back rest against relative movement; liquid by pass means interconnecting opposite ends of said cylinder; means for closing said bypass means; and means under the control of the occupant of said chair for opening said bypass means whereby the liquid of the cylinder may flow from one side of said piston to the other when a force is applied to said piston to permit the occupant of said chair to relatively adjust said seat member and back rest.
7. An adjustable chair of the type described comprising a frame; a seat member mounted on said frame; a back rest; means for pivotally" seat member; a piston in said cylinder, said piston having a rod connected to said back member;a non-compressible fluid completely filling saidcylinder; a passageway extending from one v sideof said piston to the opposite side of the jlo same; a valve normally closing said passageway; cylinder; means for connecting said cylinder and piston between a pair of relatively movable andmeans for opening said valve to open said passageway to the flow of fluid to permit movement" of said back rest relative to said seat member, said last-named means including means on lfi said fra'me and convenient to an occupant of the chair for operation by said occupant.
'8'. lhn adjustable chair of the type described comprising a frame; a seat member mounted on said frame for reciprocal movement; a back rest;
26"--mea'ns'for pivotally mounting said b c rest to saidframe; means for pivotally connectingsaid seat, member to said back rest so that movement of said seat member causes movement of said backrest; a cylinder; means for connecting said cylinder to said frame; a piston operating in said cylinder and having a rod connected to said backrest; a non-compressible fluid completely fillingsaid cylinder; means, including a passage, for flowing fluid from one end of said cylinder mi' to the opposite end when said seat member is moved; and means for closing said passage to the flow of fluid to lock said seat member against movement relative to said back rest.
9. In an adjustable chair of the type described,
a frame; a seat member; a back rest; means for mounting said seat member and back rest to said frame for relative movement; a liquid-filled cylinder; a piston operating in said cylinder; a rod carried by said piston projecting outwardly 4c of said cylinder; means for connecting said cylinder to said frame; means for connecting an end of said rod to said back rest; a passageway interconnecting opposite ends of said cylinder; a valve in said passageway; resilient means urging said valve to a position closing said passageway to the flow of liquid; means for opening said valve against the action of said resilient means to open said passageway whereby said piston may move relative to said cylinder; and means mounted on said chair convenient to an occupant of the same der; means for connecting said cylinder to said chair; a piston operating in said cylinder and having a rod connected to said back rest; a noncompressible fluid completely filling said cylinder; a passageway extending from one side of 5 said piston to the opposite side of the same so that said fluid may flow from one side of said piston to the other side thereof upon a force being exerted against said back rest; means normally closing said passageway to the flow of fluid whereby said cylinder and piston are normally held against relative movement to lock said back rest against movement; means, including means mounted on said chair convenient to the occupant thereof and adapted to be operated by said oc- 7c cupant, for rendering said last-named means inarea- 2.45;
operative sothatsaid piston may move relative. to saidcylinder to permit the occupant tochange.
the angular position of. said back rest relative to said seat member; and a coilspring, sleeving said rod and normally tending tonrge saidbaclz. rest to an upright. position whereby said: back.
rest when the chair isnot in use. willbe returned toan upright position from any adjustedangular position by operation of said; occupantsoperated'. means.
lhAnadjustable chair of thetype described,
comprising: a frame; a pair. of relatively movable.
body-supporting members mounted: thereon; a cylinder; means for mounting said cylinder to.
theundersideof said chair; apiston operatingin. said cylinder; meansfor connecting saidpiston toone. of. said. body-supporting members movable relative. to saidframe; saidcylincler being. com-v pletely filled. with a non-compressible liquid for. holding. said piston against. displacement therein whereby. said body-supporting elements are. held.
against relative movement; a by-pass, means around said. piston. valve means normally closing. said by-passv means to the flow. of. liquid; and
means,v including. means. mounted on said. chair convenient to. the occupant thereof and. operable by. saidoccupant, for rendering said valve means. operative. to. open the by-pass means to liquid flow. thereby permitting saidpiston to movewithin said cylinder and. the body-supportingmembers relative to eachother.
12 An adjustable. chair ofthe-type-described,
comprising: a frame; a. backrestangularly. ex-' tendin upwardly from said. frame; means for mounting saidback rest to. said frame for movement relative thereto whereby the angularrelationshipbetween said. frame. and. back rest can be varied; a cylinder carried by said, chair; a
piston-operating in. said. cylinder; said cylinder being completely filled with anon-compressible.
liquidwhereby said; piston may be held against movementwithinosaid cylinder; means for interconnecting.saidpistonandsaid back restwhereby said back rest may, be held against movement relative to said frame; a fluid passageway interoonnectingopposite end portions of said cylinder wherein vfiuidmay flow from one sideof the piston to. the. other; as the piston is moved relative to the, cylinder; a valve normally closing said passagewamand means for operating said valve to openlsaidpassageway to the flow of liquid to per-mitmovement of said piston relative to said cylinder. whereby said back rest may be moved. relative to saidv frame, said last-named, means including means on said frame and convenient toanoccupant of the chair for operation by said.
occupantv ARTHUR D. ARMSTRONG.
REFERENCES CITED The following references are of record in th file of this. patent: