US3230712A

US3230712A - Manual hydraulic jack

Info

Publication number: US3230712A
Application number: US266977A
Authority: US
Inventors: Charles L Redfield
Original assignee: EMIL J PAIDAR CO
Current assignee: EMIL J PAIDAR CO
Priority date: 1963-03-21
Filing date: 1963-03-21
Publication date: 1966-01-25
Anticipated expiration: 1983-01-25

Description

Jan. 25, 1966 1.. REDFIELD MANUAL HYDRAULIC JACK 4 Sheets-Sheet 1 Filed March 21, 1963 IN V EN TOR. (far/5 Z. Pdfz'efd A TTORNEYS Jan. 25, 1966 REDFIELD MANUAL HYDRAULIC JACK 4 Sheets-Sheet 2 Filed March 21, 1963 INVENTOR. (Xar/es [.Redfe'e/d Jan. 25, 1966 L. REDFIELD MANUAL HYDRAULIC JACK 4 Sheets-Sheet 5 Filed March 21, 1965 IN V EN TOR. (iaWZesLRfiifz'e/d Jan. 25, 1966 c. L. REDFIELD MANUAL HYDRAULIC JACK 4 Sheets-Sheet 4.

Filed March 21 1963 WW NW MW INVENTOR. Cfiarfes A. flea/zfa ATTORNEYS United States Patent 3,230,712 MANUAL HYDRAULIC JACK Charles L. Redfield, Downers Grove, Ill., assignor, by

mesne assignments, to Emil J. Paidar Company, Chicago, 111., a corporation of Illinois Filed Mar. 21, 1963, Ser. No. 266,977 8 Claims. (Cl. 6052) The present invention relates to improvements in support bases for beauty and barber chairs and the like having elevating and lowering mechanism for controlling the height of the chair.

More particularly, the invention relates to a chair support mechanism which permits a rotation of the chair and which operates to lock the chair against rotation and at a desired elevation. The chair is elevated by a hydraulic cylinder and piston arrangement operated by a pump of an improved design which is manually operated for elevating the chair and which incorporates a mechanism for controllably lowering the chair.

In hydraulically operated chair operating mechanisms it has been customary to employ a relatively low pressure hydraulic system with a cylinder and elevating piston fitted closely within the cylinder and being of relatively large diameter. A manually operated reciprocating pump has been used to deliver a substantial volume of hydraulic liquid with each stroke for elevating the chair. The present invention embodies a lift piston of relatively very small diameter operated by fluid under a relatively high pressure. A reciprocating pump delivers fluid in a small volume of delivery with each stroke at high pressures. This has heretofore been impractical because of the belief that low pressure large volume systems were necessary because of reduced expense and because of the need for controlled lowering of the piston at slow speeds which can easily be done with various types of release valves where a large volume of hydraulic fluid was used.

A feature of the present invention is the provision of an improved fluid handling system including a pump for delivering hydraulic fluid under high pressure and small volume and including a flow control system for relieving small volumes of fluid under complete control to assure uniform reliable lowering of a chair.

It is accordingly an object of the present invention to provide an improved support base assembly for a power elevated and lowered chair which incorporates easily operated reliably controlled elevating and lowering mechanism for manual operation and which incorporates a brake for releasably locking the chair against rotation.

A further object of the invention is to provide an improved manually operated pumping mechanism which requires less pumping force than required with devices heretofore available so as to be well suited for use on beauty chairs which usually have female operators.

A still further object of the invention is to provide an improved foot operating mechanism for operating the pumping system and braking mechanism of a beauty or barber chair or the like.

A still further object of the invention is to provide an improved operating structure for a brake mechanism for a rotatable power elevatable chair.

Yet another object of the invention is to provide an improved pump for a hydraulically operated chair embodying a fluid release mechanism for lowering the chair or for automatically terminating operation of the pump at an extreme end of the stroke or with excessive resistance to pump operation.

A still further object of the invention is to provide an improved pump embodying a fluid release control system which permits the escape or back flow of pumped fluid from an elevating cylinder for a mechanism of the type above described.

ICC

Other objects, advantages and features will become more apparent with the teaching of the principles of the present invention in connection with the disclosure of the preferred embodiment thereof, in the specification, claims and drawings in which:

FIGURE 1 is a perspective partially exploded view of a support base mechanism embodying the principles of the present invention;

FIGURE 2 is a perspective partially exploded enlarged view of a portion of the mechanism of FIGURE 1 with parts broken away;

FIGURE 3 is a detailed vertical sectional view of the.

pump plunger assembly;

FIGURE 4 is a perspective fragmentary view of the brake mechanism;

FIGURE 5 is a detailed vertical sectional view of cylinder and piston for elevating the chair;

FIGURE 6 is an enlarged fragmentary detailed view of the mechanism for controlling the release of fluid to lower the chair, with parts shown in release position;

FIGURE 7 is a fragmentary detailed sectional view showing the position of parts of the elevating cylinder and piston and of the pump whenthe chair is being lowered; and

FIGURE 8 is a fragmentary detailed elevational view with parts omitted showing an alternative form of a portion of the structure.

On the drawings: 7

The support base for the barber chair incorporates a lower platform member 10 which has a lower support surface for resting on a floor. A vertical column member 11 is mounted on the platform member and extends upright to support a chair or the like at its upper end. The column member 11 includes a hollow tubular column 12 with a post or shaft 13 slidably mounted therein, and at its upper end the post 13 has an attachment plate 14 to which the seat of a chair is secured.

The vertical support column 11 is suitably mounted on the the platform member 10 such as by bolts 15 which ex-' tend upwardly from the platform member and are received by holes in flanges 16 on the column member and nuts fit over the bolts 15 to rigidly secure the column member in an upright position.

Mounted on the column member is a brake 17, shown in detail in FIGURE 4, which is released or locked, and in the locked position the post 13 is held against rotation and held vertically to hold the chair is a fixed position.

The chair is manually operated by a foot pedal 18 which is moved up and down to operate a pump 20. The foot pedal is moved up and down to operate the pump 20 in a normal stroke, or can be pushed down to an extreme lowered position beyond the normal stroke which is a release position for lowering the chair. The foot pedal can also be raised to an extreme upper position which is the braking position for locking the brake 17 to hold the post 13.

The pump 20 delivers fluid to a lift tube or cylinder assembly 19 having a piston therein for raising or lowering the chair. This-structure is shown in greater detail in FIGURE 5, and an alternate form is illustrated in FIGURE 8 and will be described further.

At the base of the tubular column 12 is a shaped base plate 21 to form a reservoir R within the column for bolding a supply of hydraulic fluid. The fluid normally will be at the level L, FIGURE 2, to submerge the lower end of the lift tube 19 and pump 20. The base plate 21 is shaped and provided with threads so that the lift tube or cylinder 19 can be secured by being threaded therein with its lower end 24 being externally threaded.

Within the cylinder 1? is a piston 23 which is in the shape of a rod of uniform diameter smaller than the inner diameter of the cylinder 19. This type of piston permits using rod stock without requiring precise machining. At the lower end of the piston is a guide ring 25 snapped into a groove in the piston 23, and the upper end of the piston is guided by a bushing 27 secured into the upper end of the cylinder. An annular seal 28 surrounds the piston and prevents leakage from the cylinder, and the seal is held in place against a snap ring 29 by the bushing 27. The seal is of a flexible material which prevents the escape of hydraulic fluid under pressure from within the cylinder 19 and since the upper end of the cylinder is within the reservoir R any fluid leakage will flow down the outside of the cylinder down into the pool at the lower end of the reservoir R.

The upper end of the piston isshown at 26 as having a spherically'shaped surface. This will seat into a complementary shaped spherical socket 26a within the post 13so'that the axis of the post 13 and the axis of the positon 23 do not have to be exactly aligned. This permits completely satisfactory operation of the post by the piston.23. do not have to be exactly aligned. This perpensive aligning procedures.

The base plate '21 is also shaped to provide a pump cylinder or chamber 31. The chamber i cylindrically shaped and communicates with the lower end of the chair elevating cylinder 19 through a passageway 30, and at the lower end of the pump cylinder is a fluid delivery port 33. Positioned in this port is a check valve including a spherical v'alve ball 34 with a spring 35 urging it against a valve seat 36 to prevent'theescape of fluid from'the cylinder 19. The pump chamber 31 has a fluid inlet check valve 32 which receives flu'id from the reservoir through a passage 32a of the valve '32. The pump chamber has a bushing 37 at its upper end for receiving the pump plunger 39, and a flexible seal 38 is held beneath the bushing and seats on a shoulder in the pump chamber.

Above the pump plunger 39, FIGURES 2 and 3, is a plunger drive member 40. The drive member projects upwardly'throughan opening in the tubular column and is operated by a brake and drive member operator 41a, FIGURES 1 and 4. Rigid arms 41 extend laterally outwardly from the operator'41a and links 42 connect pivotally to the ends of the arms. Teh lower ends of the links 42 pivotally con'nect to arms 43 on the foot pedal 13.

"The operator 41a also operates the brake 17 which includes an annular :brake band 44 which is split at one side so as to be contractible. The band has an inner wiper ring 45 mounted in a groove therein which acts as a seal and prevents dust from being dragged down with the shaft 13 as it descends, or prevents oil from working upwardly with the shaft when it is elevated. It will be noted that the shaft at its lowered position will extend down beneath the level of the fluid in the reservoir R to provide some lubricant for the shaft, and to lubricate it against its bearing surfaces 132; in the tubular column.

The brake is supported at the upper end of its tubular column by threaded pins 46, FIGURE 1, which extend down through openings 47 in the brake band and are threaded into the holes 46a in the tubular column. The pins 46 are of a diameter less than the holes 47 so as to permit expansion and contraction of the brake band 44, and the pins 46 have shoulders near their lower ends as to limit the distance they are threaded into the column and so that their heads will not bind against the top surface of thebrake band 44.

The brake band is radially contracted and released by

arms

48 and 49. The arm 48 is mounted on a support block 50 secured to one side of the band, and the arm 49 ismountedon a pivot bolt 4% on the other side of the split band 44. The support block 50 may have a shim member 50a beneath it to adjust its position and thereby adjust the clamping pressure of the band.

The arms are interconnected by a pivotal pin 52 which is onthe end of the-arm 48- and which slides in a radially extending slot 53 in the arm 49. As will be observed in FIGURE 4, when the arms are in their solid line locking position the pin 52 is in the base of the slot 53. When the arms are in their dotted line brake release position, the pin 52 is free to slide downwardly in the slot 53. This permits up and down movement of the arm 48 when the pump is operated by the foot pedal '18 being moved up and down. The operator 41a is connected to the arm 48 by a pin 55 which extends through a slot 54 in the arm 48. This permits the operator 41a to move up and down in a straight line motion. Thus the

arms

48 and 49 provide a toggle linkage'which apply the brake in the solid line position of FIGURE 4, and which move down to the dotted line release position'without interfering with the operation of the pump in the release position. The arm 43 is generally curved or may be described'as L-shaped so that the'pivotal supports for the arms may be in a straight horizontal line forthe toggle action of the arms in locking the brake.

The pump plunger 39 is connected tothe plunger drive member 41) through a very strong coil compression spring 50 that remains substantially rigid during normal operation. The compression spring '50 is undersome compression so that when the drive member 40 pushes downwardly on the pump plunger 39the force will be transmitted through the drive spring 50. Return movement ofthe pump plunger in an upward direction is accomplished by a coil compression return spring 51 which rests 'on the base plate 21 at its lower end and engages a spring'supporting collar 54 at its upper end. The collar 54 rests on a lock ring 55 snapped in a groove in the plunger 39..

The lower end 39a of the plunger 39 functions as a plunger stop, and engages an upper stop surface 31a at the range in a downward direction plunger end 39a will engage the stop surface 31aso that continued downward movement of the drive member 40 will compress the strong spring 50. This will release fluid from beneath the elevating piston 23 as will be more fully described.

The upper end of the spring 50 engages a collar 52 which is slidably mounted on a valve housing 59* which forms the upper portion of the pump plunger, and is threadably secured thereto.

A snap ring 53 locks in a groove in the valve housing 59 to limit the upward travel ofthe collar 52. The drive member 40 has an upper elongated tubular portion 40a and a lower cup-shaped flange portion 40b which rests on the collar 52. The force of the plunger drive member 40 is thus transmitted downwardly by theportion 46b engaging the collar 52 which in turn engages the plnnger drive spring 50. The plunger drive spring 50 will compress in either of two situations to relieve the pump and to lower the elevating piston 23. The first situation is when the pedal 18 is pushed down to its extreme lowermost release position. At this position the lower check valve 34 will be opened by a lower tubular sleeve pro jection 57 engaging the valve ball 34 and pushing it off of its seat in the manner shown in FIGURE 7. This permits fluid to flow from the cylinder 19 up through a passage 58 extending through the plunger 39. Compression of the spring 50 will also unseat a-ball check valve 60 from its seat 62 where it is held by a spring 61.

The ball 60 remains seated during normal operation of the pump plunger to prevent the escape of hydraulic fluid. However, when the spring 50 compresses, the ball 60 is,pushed off of its seat by a tubular split projection 65. The projection 65 is carried onthe lower end of a relief plunger 63. carried on the drive member. The. relief plunger slides in the valve housing 59 in a bore. therein, and the relief plunger 63 is sealed to the bore by an annular flexible seal 64. The-drive spring 50 will also compress when the pump is overloaded-such as when v .the lift piston 23 reaches the top of its travel, which is the second situation referred to above.

The relief plunger 6'3 has a central smooth bore 72 which receives a valve stem 73. The valve stem is threaded and the space between the lands of the threads provide a flow path for the relatively slow escape of hydraulic fluid which flows upwardly past the check valve ball 60. The fluid escapes laterally through a radial escape opening 66 and flows downwardly into the reservoir such as through a groove 74 in the collar 52, which will of course move downwardly away from the lock ring 53 as shown in FIGURE 6. The bore 72 could also be threaded to further restrict flow but the size of the threads of the stem 73 will control the range of valve flow.

The valve stem 73 is vertically adjustable, and the length as it is turned down into its bore 72 will determine the escape rate of hydraulic fluid.

For this purpose, the valve stem 73 passes through a retainer bushing 67 at the top of the release plunger 63, and is supported by a threaded head 68 at its upper end. The head is adjustably threaded into the upper portion 40aof the drive 40. A cap 70, FIGURE 2, is threaded into the upper end of the upper portion 40a of the drive 40 and the cap has a tapered head to fit into a recess in the operator 41a.

Since the elevating cylinder 19 is of a relatively small capacity, the amount of fluid released for lowering the elevating piston 23 at a controlled rate must be small. The path of the threads of the valve stem 73 provide this limited path. To prevent any foreign particles from flowing upwardly to block the path of the threads or to prevent the ball 60 from seating, a filter screen pack 69 is positioned across the passage 58 held in place below the check valve spring 61, FIGURE 3.

The upper end of the plunger drive is supported by a .bushing and seal assembly 71 where it passes through the opening in the tubular column 12.

Thus, oil is permitted to bleed from the pump by opening the check valve ball 60 at any time when the drive plunger spring 50 compresses and when the plunger is fully down in its release position the fluid will be released from beneath the elevating piston 23, and when excessive back pressure is encountered by the pump plunger at any time during its stroke, the drive spring 50 will compress to unseat the valve ball 66 in the manner shown in FIG- URE 6. The strength of the spring 50 and its initial compression is chosen so that it will not compress during normal pump operation, but will compress when excessive back pressures are encountered by the pump plunger, such as when the elevating piston reaches the top of its travel and its ring engages the ring 27, FIGURE 5, at the top of the cylinder 19.

FIGURE 8 illustrates a modified form of assembly for the elevating cylinder-and pump chamber. The assembly includes a lower plate 74 and an upper plate 75. The upper plate is fitted with holes so that it may be mounted on the lower end of the tubular column.

The elevating cylinder 76 seats in an opening in the upper plate 75 and rests against the lower plate and is held in place by a lock ring 77 seating in an annular groove in the cylinder and engaging a spacer ring 78 which bears against an annular seal 79. The seal prevents fiuid from escaping past the opening in the lower plate which receives-the cylinder 76. The plates are sealed with respect to each other by an annular seal 86 and the plates are held together by bolts 85. The space between the plates defines a flow passage 87 for delivering oil to the cylinder which is provided with openings, not shown, for the oil to flow up into the cylinder. Fluid is delivered to the passage 87 through a pump discharge .port 90 from the pump plunger chamber 88 which takes hydraulic fluid in from the reservoir through a filter 89. The pump chamber 88 is supported on the upper plate 75 by 1a sock ring 83 and is sealed to the plate by an annular sea 4.

The elevating cylinder 76 is provided with an elevating piston 80. An annular lower limit spring '81 is mounted at the top of the cylinder 76, and this spring has a washer 82 at its upper end which is engaged by a stop collar (not shown) secured to the piston 80. When the piston is dropped to its lowermost position in which it is shown in FIGURE 8, the lower end is prevented from hitting the base of the cylinder, and a cushioned termination of drop is provided by the stop collar engaging the washer at the upper end of the spring 81.

In summary, the mechanism is operated by the foot pedal 18, FIGURE 1, which is raised to its uppermost position to apply the brake band 17 by swinging the

arms

48 and 49 into their aligned locking position.

When the foot pedal 18 is moved downwardly below the breaking position and pumped up and down, the plunger drive 40 operates the pump plunger 39 to force hydraulic fluid out through the plunger discharge port 33, FIGURE 5, up into the cylinder 19 to elevate the elevating piston 23.

When the chair is to be lowered, the pedal 18 is pushed to its lowermost release position, and the projection 57 unseats the check valve ball 34, FIGURE 7. Fluid flows up through the passage 58, FIGURE 3, in the pump plunger 39. The spring 50 will have been compressed 'by the plunger end 39a hitting the upper surface 31a of the pump chamber thus causing the projection 65 to unseat the check valve ball 60. The rate of escape of fluid is determined by the position of the valve stem 73 and the fluidescapes through the threads of the stem out through the lateral opening 66 to gradually lower the chair elevating piston 23.

The ball check 60 also functions to relieve the pump such as when the chair reaches its uppermost position and no more fluid can be pumped into the cylinder 19. This release is accomplished by excessive back pressure stopping further travel of the pump plunger 39 causing the spring 50 to compress.

Thus it will be seen that I have provided an improved chair elevating asembly which meets the objectives, advantages and features above set forth.

The assembly employs an elevating piston 23 of considerably smaller diameter than has heretofore been used and rod stock can be employed without necessitating close machining tolerances. A flexible seal surrounds the rod stock and a simple tube provides the cylinder 19. The small capacity of the elevating mechanism makes it possible to use a pump with a small delivery. This reduces the weight of the parts, and reduces the size of the parts thereby diminishing the frictional surface areas. The resultant pump can be operated with a minimum of effort making the pump and elevating mechanism well suited to use in beauty parlor equipment which usually must be operated by female operators.

As will be recognized from the foregoing the structure is relatively simple and small as compared with mechanism heretofore used wherein low pressure large capacity elevating cylinders and pistons were used requiring large capacity low pressure pumps. Yet the control valve arrangement makes it possible to obtain controlled release of the fluid for lowering of the chair at very small flow rates, and this is accomplished through mechanism embodied in the pump.

The plunger'39 is of small diameter and for a beauty chair has a diameter preferably in the order of /2 inch, and in the range of inch to /8 inch. The pump preferably has a volume delivery of .20 cubic inch per stroke, and in the range of .05 cubic inch to .50 cubic inch per stroke. The pump plunger 39 may be of substantially the same diameter as the lift piston 23 and the pump has a nominal 1 inch stroke.

The drawings and specification present a detailed disclosure of the preferred embodiments of the invention, and it is to be understood that the invention is not limited to the specific forms disclosed, but covers all modifications, changes and alternative constructions and methods falling within the scope of the principles-taught by the invention.

I claim as-my invention:

1. Ina support base for a barber chairor the like having an upright elevating cylinder and piston for supportin'gly connecting to a chair, the combination com prising,

a'pump' chamber having a discharge portat one end communicating with the cylinder,

a one-way check valve in said port, a pump plunger slidable in said chamber in a normal stroke length and movable to unseat said check-valve,

a passage through said plunger extending to an exhaust,

a release valve normally Closing said passage,

a valve operator carried by the pump plunger, means for biasing said valve operator away from saidrelease-valve during said normal stroke,

a valve operating stop engaged by said plunger at the end of said normal stroke of the pump plunger, said valve operator movable relative-to saidplunger and against said biasing means after engagement of said plunger against said stop to open said release valve, and an adjustable fio'w restrictor in said passage carried on the plunger limiting flow through the passage to a predetermined flow with the opening of thevalve.

2. In a support base for a barber chair or the like having an upright elevating cylinder and piston forsupportingly connecting to a chair, the combination comprising,

a pump chamber having a discharge port communicating with the cylinder, a one-way check valve in said port,

a pump plunger slidable in said chamber ina' normal stroke length and-movable to unseat said check valve,

a passage through said plunger extending to an exhaust,

a release valve normally closing said passage,

a plunger drive member,

a strong spring connecting the drive member to the plunger maintaining a substantially non-yieldable connection during'said normal stroke,

a plunger stop engaged by the plunger at the end of said normal stroke so that said spring will yield with the continued travel of the drive member,

and a valve operator for opening said release valve operated by movement of the drive member relative to'the plunger.

3; In a support base for a barber chair or the like having an upright elevating cylinder and piston for supportingly connecting to a chair, the combination comprising,

a pump chamber having a discharge port communicating with the cylinder,

a one-way check valve in said port,

a pump plunger slidable in said chamber in a normal stroke length and movable to unseat said check valve,

a passage through said plunger extending to an exhaust,

a release valve normaly closing said passage,

a plunger drive member,

a strong spring connecting the drive member to' the plunger maintaining a substantially non yieldable connection during normal operation, 7

said spring having a strength to'be substantially non-yieldable at normal loads and to yield with excessive resistance to plunger movement,

a plunger stop engaged by the plunger atvthe end of said normal stroke,

and a valve operator for opening said release valve operated by movement of the drive member relative to the plunger so that said valve will be opened'when said plunger terminates movement by engagement with said plunger stop or by encountering excessive resistance.

4. In a support base for a barber chair or the like having an upright elevating cylinder and piston for supportingly connecting to a chair, the combination comprising,

a pump chamber having a discharge port communicating with the cylinder,

a one-Way check valve in said port,

apump plunger slidable in said chamber in a normal stroke length and movable to unseat said check valve,

a passage through said plunger extending to an exhaust,

a release valve normally closing said passage,

a plunger drive member,

a strong spring connecting the drive member to the plunger maintaining a substantially 'non-yieldable connection during normal operation,

said spring having a strength'to be substantially non-yieldable at normal loads and to yield with excessive resistance-to plunger movement,

and a valve operator for opening said release valve operated by movementof the drive member relative to the plunger so that said valve will 'be opened with excessive resistance to plunger movement.

5 In a support base fora'barber chair or the like having an upright elevating cylinder and piston for supportingly connecting tofa chair,-thecombination comprising,

a pumpchamber having a discharge port communicating with the cylinder,

a one-Way check valve in said port,

a pump plunger slidable in said chamber in anormal stroke length and movable to unseat said check valve,

a passage through said plunger,

a'release' valve normally closing said passage,

- a valve operator carried by said punip'plunger, means for-biasing said valve operator away from said'release valve during said normal stroke,-'said valve operator being movable relative to said-plunger and against said-biasing means at the end of said normal stroke to open said release-valve, and a flow control valve carried on-said' plunger and 1 positioned in said passage in-series with said release valve including a threaded elongated opening,

' and a threaded valve stein adjusta'bly threaded into said opening defining a flow path between the stern and threadedwallof the threaded opening so thatthe rate of escape of fluid from said cylinder may be controllably varied by varying the position of the valve stem.

6. In a support base for a barber chair or the like having an upright elevating cylinder and piston 'forsuppo'rtlngly connecting to'a chair, the combination comprising,

a pump chamber having a discharge port communicating With the elevating cylinder, a one-Way check valve in said port,

a pump plungerslidable in said chamber in a normal stroke length to unseat said check valve,

a passage through said plunger extendingto an exhaust,

a release check valve in said passage normally preventing the escape of fluid from said pump chamber,

a plunger drive member,

a strong spring connecting the drive member to the plunger maintaining a substantially non-'yi'eldable connection during normal stroke length,

said spring having a strength to be substantially non-yie-ldable at normal loads and to yield with excessive resistance to plunger movement,

and a valve operator connected to said drive "member positioned to engage said release check valve and force it to open position with movement of the drive member relative to said plunger and corresponding yielding of said spring.

7. In a support basefor a barber chair or the like having an upright elevating cylinder and piston for supportingly connecting to a chair,

a pump plunger slidable in said chamber in a normal stroke length to unseat said one-way check valve,

a passage through said plunger extending to an exhaust,

a plunger drive member,

a strong coil compression spring extending between the drive member and plunger and transmitting drive 10 her and moving it to open position in said release position of the plunger, a plunger drive member extending above the plunger in substantial axial alignment therewith,

forces from the drive member to the plunger, a coil compression spring surrounding the plunger and said spring being sufiiciently strong to be substanconnecting the drive member to the plunger,

tially non-yieldable with normal resistance to said spring being held compressed between opplunger movement, posed stop washers locked to said plunger, a release check valve in said plunger passage having a passage extending through said plunger communicata seat facing in the direction of movement of the ing with the pump chamber, plunger in its discharge stroke and having a valve a check valve in said passage preventing the escape member urged by a spring against said seat to preof fluid therefrom, vent escape of fluid through said passage, a projection on said drive member engaging and openand a projection on said drive member spaced from ing said check valve with relative movement be the valve member during said normal stroke length tween the drive member and plunger due to compresof the plunger and drive member and engaging the sion of said spring, valve member to move it away from said seat with a stop engaged by said plunger at the end of said norcompression of said spring. mal stroke to cause compression of said spring, 8. In a support base for a barber chair or the like said spring having a strength to yield with undue having resistance to movement of the plunger to permit a platform member having a base for supportingly encontinued movement of the drive member,

gaging a fioor surface, a threaded bore in series with said passage, and a a tubular column extending upright from said platform threaded valve stem in said bore controlling the rate member with an open upper end, of escape of fluid from said passage so that the rate a chair supporting shaft slidably mounted and support- 0f d s nt f th aft Will be Controlled in the ed in said tubular column, release position of said plunger. a brake mounted on said column for being releasably locked around i h ft References Cited by the Examiner said column defining a fluid reservoir at the lower U D STATES PATENTS end thereof 885 564 4/1908 Barker 60 52 a chair elevating cylinder mounted within said column 885843 4/1908 1 rscher 60*52 in said reservoir and having a piston shdable therein 1 069 863 8/1913 Des 60 52 connected to said shaft for elevating and lowerin the p1 S 0 1,745,024 1/1930 Malone 60--52 Chan, 1,999,848 4/1935 Ries 6052 a pump mounted upright in said reservoir having a 2 194 340 3 1 Ware et a1 188 77 chamber with a discharge port communicating with 2 29 954 9 1942 Schneiden the elevating cylinder and having a plunger movable 2,397,042 3 194 Pf t 6Q 52 Wi n i h mb r, 2,455,439 12/1948 Page 188 7 a spring loaded check valve having a member engaging 40 2,909,123 10/1959 Jennings 60--52 X a seat and located in said port, 2,969,645 1/ 1961 Kiefer 6052 saidt plllimger1 rlrliovable in 1said chamber Iijn a ngrma FOREIGN PATENTS s ro e an avmg a re ease pos1t1on eyon sa1 545,428 10/1959 Belgium.

normal stroke,

a projection on said plunger engaging said valve mem- JULIUS E. WEST Primary Examiner

Claims

1. IN A SUPPORT BASE FOR A BARBER CHAIR OR THE LIKE HAVING AN UPRIGHT ELEVATING CYLINDER AND PISTON FOR SUPPORTINGLY CONNECTING TO A CHAIR, THE COMBINATION COMPRISING, A PUMP CHAMBER HAVING A DISCHARGE PORT AT ONE END COMMUNICATING WITH THE CYLINDER, A ONE-WAY CHECK VALVE IN SAID PORT, A PUMP PLUNGER SLIDABLE IN SAID CHAMBER IN A NORMAL STROKE LENGTH AND MOVABLE TO UNSEAT SAID CHECK VALVE, A PASSAGE THROUGH SAID PLUNGER EXTENDING TO AN EXHAUST, A RELEASE VALVE NORMALLY CLOSING SAID PASSAGE, A VALVE OPERATOR CARRIED BY THE PUMP PLUNGER, MEANS FOR BIASING SAID VALVE OPERATOR AWAY FROM SAID RELEASE VALVE DURING SAID NORMAL STROKE, A VALVE OPERATING STOP ENGAGED BY SAID PLUNGER AT THE END OF SAID NORMAL STROKE OF THE PUMP PLUNGER, SAID VALVE OPERATOR MOVABLE RELATIVE TO SAID PLUNGER AND AGAINST SAID BIASING MEANS AFTER ENGAGEMENT OF SAID PLUNGER AGAINST SAID STOP TO OPEN SAID RELEASE VALVE, AND AN ADJUSTABLE FLOW RESTRICTOR IN SAID PASSAGE CARRIED ON THE PLUNGER LIMITING FLOW THROUGH THE PASSAGE TO A PREDETERMINED FLOW WITH THE OPENING OF THE VALVE.