US 3179369 A
Description (OCR text may contain errors)
April 20, 1965 D. H. HALE 3,179,369
POWER-OPERATED UTILITY STOOL Filed July 3, 1962 2 Sheets-Sheet 1 2/ F/GQ F/G. Z. 20 n n 34 as INVENTOR. DEAN H. HALE ATTORNEYS A ril 20, 1965 D. H. HALE POWER-OPERATED UTILITY STOOL 2 Sheets-Sheet 2 Filed July 3, 1962 ATTORNEYS United States Patent 3,179,369 POWER-OPERATED UTILITY STOOL Dean H. Hale, Logan, Utah, assignor to Vacudent Manufacturing Company, Salt Lake City, Utah, a corporation of Utah Filed July 3, 1962, Ser. No. 207,209
3 Claims. (Cl. 248-404) This invention relates to power-operated utility stools and is especially but not exclusively concerned with the type of utility stool which forms the subject of my copending application for patentSerial Number 144,980, filed October 13, 1961, now Patent No. 3,145,053, entitled Utility Stool and of copending application Serial Number 144,862, filed October 13, 1961, now Patent No.
7 3,147,946, by Elbert 0. Thompson and me jointly, entitled Stool for Dentists.
The stools of these applications for patent include selfcontained power units controlled by foot pedals extending outwardly from and below the periphery of platform bases. It has been found that such foot pedals are not only diflicultto locate by occupants of the stools groping for it with a foot while giving major attention to work in progress, but also can be inadvertently stepped on at inconvenient times during the progress of such work, thereby posing a danger to orderly conduct of the work.
The present invention avoids both these difiiculties and enables an occupant of the stool to have positive, convenient control of seat raising and lowering at all times, without undue groping with the feet and Without'danger of inadvertent actuation.
' A feature of the invention is the provision of a ring or partial ring closely surrounding the center post of the stool immediately above the platform base as a part of a treadle for actuating the power control.
A specific embodiment representing what is presently regarded as the best mode of carrying out the inventive concepts in connection with the stools of the aforementioned patent applications is illustrated in the accompanying drawings. From the detailed description of such embodiment adaptations to other stool constructions will be obvious.
In the drawings:
FIG. 1 represents a front elevation of the stool with its seat in a lowered position;
FIG. 2, a top plan;
FIG. 3, a bottom plan;
FIG. 4, a fragmentary vertical section taken on the line 44 of FIG. 3 and drawn to a-considerably larger scale;
FIG. 5, a similar section taken on the line 5-5 of FIG. 3; and
FIG. 6, a view corresponding to that of FIG. 5 but showing the foot-operated ring depressed and the seat of the stool thereby raised to an elevated position.
Referring to the drawings:
The stool of FIGS. 1 and 2 is constructed in substantially the same manner as those of the patent applications above noted. 'Thus, a circular seat is supported in stool fashion at the upper end of a post 11, which depends centrally from the seat into a receiving tube 12. Post 11 and tube 12 together form part of an extendible and retractable hydraulic assembly mounted ina base 13, tube 12'being fixed therein as by Welding. V
Base 13 is platform-like and hollow, being maneuverably supported by castors 14. There must be at least three castors for stability, as is quite apparent, but there 7 3,179,359 Patented Apr. 20, 1965 effectively rest his or her feet ed the floor when found desirable.
For added strength and to facilitate lubrication, a sleeve 15 is secured to the upper end of tube 12 and extends down to the base 13 as a tube housing, where it is secured as by welding. A ring of oil-impregnated felt 16 wipes oil onto the surface of post 11 as it rises and descends relative thereto.
In order to provide support for the trunk of the body of the occupant, for example a dentist or dental assistant, when working from a seated position and leaning outwardly from the seat 10, an abdominal rest 17 is provided in upwardly spaced relationship with the seat. It is supported in what is essentially cantilever fashion from a post 18, which is preferably a broad and rigid bar or strip of some such material as steel or aluminum rising above the seat near the circumference thereof.
Body rest 17 is of broad strip formation in the sense that it is wide but relatively elongate, so as to provide comfortable and effective support for the body at or near the waist. It and ,seat 10 are preferably cushioned with foam rubber or the like and upholstered with a Washable plastic sheet material.
While in some instances it'rnay be desirable to construct the stool with the body rest permanently fixed to its supporting post, in the illustrated construction rest 17 is adjusably positioned relative to post 18 so as to accommodate thin as well as stout persons. In any event, the rest is largely curved in conformity with the seat and is positioned so that its width extends vertically and so that its length extends horizontally in cantilever fashion from one side of the post.
.To enable a person to easily move into and out of position on the seat with respect to the body rest, such body rest preferably has its opposite end portions deviating outwardly from the aforespecified curvature, the end por tion 17a nearest the supportingg post 18 advantageously being rectilinear or approximately so. Best results are had when the circularly curved intermediate portion of e the rest subtends an angle of about For the purpose of adjustment, rest 17 is provided with a bracket arm 19, which extends from near the middle of such rest backwardly and outwardly along the back of one end portion of the rest, ,see particularly FIG. 2, and is firmly secured to post 18 by suitable releasable fastening means, such as the hand-operated clamping screw 29 threaded into slideway 21. In turn, post 18 is firmly but adjustably secured to the rest of the stool structure by means of a second clamping screw 22 threaded into slideway 23.
Slideway 23 is secured, as by welding, to the outer and upwardly turned end of a mounting bar 28, so that its throughway is disposed. vertically for slidably receiving post 18, While slideway 21 is similarly secured to the upper end of post 18 with its throughway disposed horizontally for slidably receiving bracket arm 19.
Mounting bar 28 is secured, as by welding, to the upper end of post 11, and, in order, to provide for independent .swiveling movement of seat 10 and body rest 17 relative to each other, an anti-friction bearing 29, FIG. 5, has its upper race plate 29a secured to the seat, as by bolts 30, and its lower race plate 2% secured to mounting bar 28 and post 11, as by welding.
The self-contained power mechanism for raisingseat 10 and, coincidentally, body rest 17 is housed within hollow base 13. It is of hydraulic type and utilizes captive air under pressureto force a non-compressible hydraulic fluid, sucha oil; into the lower end of tube .12.
i A reservoir 32 for the pressure air and hydraulic fiuid communicates with the lower end of tube or cylinder 12 by means of a conduit 33, in which is interposed a normally closed valve 34 of standard type having a spring-loaded plunger 35 for controlling flow of the pressurized hydraulic fluid to and from tube 12. As such, valve 34 constitutes means for controlling operation of the power means represented by pressurized reservoir 32.
Conduit 33 'is directly connected to a T fitting 36, which has its lateral connected by a nipple 33-1 to a check valve arrangement 37 formed at the lower end of tube 12 and containing a seat 38 for a ball check 39. An air-injection fitting 41 is connected to the other end of T 36 and isequipped with a standard air-injection valve (not shown) similar to those used for pneumatic tires, whereby compressed air can be introduced from an ordinary air hose for initially charging reservoir 32 to a pressure of from about 60 to 80 p.s'.i. and for repressurizing if and when necessary.
Inasmuch as tube 12 and check valve body 37 depend deeply into base 13, braces 42, extending and secured to the underside of base 13, are provided for strength and stability.
Seat-supporting post or piston 11 fits tube 12 snugly along a lower end portion 11a, but is of reduced diameter above to provide a shoulder 11b which serves as an abutment stop when it reaches cap 15-1 of sleeve 15 in the upward adjustment of seat height.
Post 11 is preferably made with its lowest portion as a separate part 11-1, to which is attached a cup seal 43. In this way, seat 10 and its post 11 are free to be moved upwardly independently of seal 43 and there is no possibility of damaging such seal by forced raising of the seat, apart from power actuation, as would be the case were the post not made up of separate parts. Such parts are preferably abruptly tapered where they meet, as shown at 11-2, to provide a relief area..
In accordance with the present invention there are provided means for actuating the control means, which include a foot-operated portion at least partially surrounding the seat-supporting post structure previously described, closely adjacent thereto and immediately above the upper surface of the base.
As illustrated, it is preferred that such foot-operated portion be a ring 44 encircling the post structure and that such actuating means include a lever operable on plunger 35 of valve 34, so that foot power applied anywhere along the extent of ring 44far inwardly of the top of platform base 13-will easily push such plunger inwardly of the valve to open same and cause seat 10 to be raised by extension of its supporting post structure.
The lever shown is very satisfactory, operating smoothly and positively to accomplish its purpose. It comprises a pair of rods 45 depending slidably through suitable openings provided in the top of base 13, the defining edges of such openings being preferably lined with rubber grommets 46 to eliminate metal-to-metal contact in the sliding movement of such rods.
A bearing ring 47 is slidably mounted on the lower end of tube 12 so as to be slidable upwardly and downwardly of the lower end of the post structure. The lower ends of rods 45 are connected to ring 47 at diametrically opposite portions thereof, and a lever arm 48, FIGS. and 6, projects therefrom toward valve 34 intermediate the two rod connections.
Leverarm 48 is secured to another lever arm 49, provided as part of valve 34 and pivoted at its far end so thatring 44, rods 45, ring 47, and lever arms 48 and 49 become a single lever of the second class fulcrurned at the pivotal connection 50 of lever arm 49 with the body of valve 34.
The height of stool seat is adjusted by pressing footring 44. It is not intended in this illustrated embodiment that there be a lifting of a person seated on the stool, but, rather, that there be a powered lifting of the stool seat 10alone, sincethisis all that is necessary from a practical standpoint. Thus, when the dentist or other person using the stool desires to alter his working position upwardly, he need merely step on the foot-ring while raising his body. The stool seat will closely follow until pressure on the foot-ring is released, whereupon a sitting position can be resumed without ever having taken eyes or hands from the work in progress. It is apparent that opening of valve 34 permits the entrapped compressed air in reservoir 32 to expand and force hydraulic fluid from such reservoir into tube 12.
Ball check 39 is preferably of steel or other heavy material, so as to seat when post 11 and its auxiliary part 11-1 are raised as in FIG. 6. Thus, when it is desired to lower the height of stool seat 10 and foot-ring 44 is pressed for that purpose, the hydraulic fluid is trapped against rapid escape from tube 12 and there is no sudden descent of the seat. Instead, a bleeder passage 51 provides for gradual return of fluid to reservoir 32 and, therewith, a gradual lowering of such seat.
It should be realized that, because the reservoir is pressurized, it will be necessary for the user to rest his or her weight on the stool seat While the foot-ring is pressed in order to lower such seat from any given height.
Such foot-ring 44 is easily located by either foot of the user of the stool, without groping. Yet, it is out of the way of the area of the platform base normally used as a foot rest. Thus, there is little danger of inadvertent pressing of the ring as work progresses from the stool as a work center.
Whereas there is here illustrated and described a certain preferred construction which I presently regard as the best mode of carrying out my invention, it should be understood that variou changes may be made without departing from the inventive concepts particularly pointed out and claimed herebelow.
I claim: I
1. A utility stool, comprising a platform base; a seat; extendible and retractable post structure rising from said base centrally thereof and supporting the seat; power means for extending said post to raise the seat; means carried by and located within the base for controlling operation of the power means; and actuating means including a foot-operated ring portion encircling said post structure closely adjacent thereto and immediately above the surface of the base, and a depending member extending downwardly from the foot-operated portion thereof into operative relationship with the means in the base for controlling operation of the power means.
2. The stool of claim 1, wherein the power means include a hydraulic system, the control means is a plungeroperated valve, and the actuating means include a lever operable on said plunger, power being applied through the foot-operated portion thereof.
3. The stool of claim 2, wherein the foot-operated portion of the actuating means is a ring encircling the post structure, and the lever comprises a pair of rods depending slidably through the top of the base from diametrically opposite portions of said ring, a bearing'ring slidable along the lower end of the post structure and having diametrically opposite portions connectedto said rods, respectively, and a work arm projecting from the bearing ring.
References Cited by the Examiner UNITED STATES PATENTS 2,218,963 10/40 Stephenson 108-144 2,231,631 2/41 Maina 248-461 2,620,863 12/52 Cooper 297--46 2,836,080 5/58 Mullett 74-512 FOREIGN PATENTS 1,039,723 5/58 Germany.
, CLAUDE A. LE ROY, Primary Examiner.