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Publication numberUS762086 A
Publication typeGrant
Publication dateJun 7, 1904
Filing dateMay 6, 1903
Priority dateMay 6, 1903
Publication numberUS 762086 A, US 762086A, US-A-762086, US762086 A, US762086A
InventorsFrank Ritter
Original AssigneeFrank Ritter
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Dental chair.
US 762086 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)




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No. 762,086. PATENTED JUNE 7, 1904.




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A 0 9 1 l E N U J D E T N E T A P R I RA EH Tc HL RA T FN B .D 00 8 2 6 7 nw N APPLIUATION FILED MAY 6, 1903.

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Inventork Attorney- PATENTED JUNE 7, 1904. P. BITTER.







' Attorney- .UNITED STATES Patented June 7, 1904.



SPECIFICATION forming part of Letters Patent No. 762,086, dated June '7', 1904.

Application filed May 6, 1903. Serial No. 155,955.

To all whom it may concern:

Be it known that I, FRANK RITTER, of th city of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Dental Chairs; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the reference-numerals marked thereon.

My present invention relates to dental, surgical, or barbers chairs, such as are adapted to be adjusted vertically by hydraulic power; and it has for its object to provide an improved form of base or supporting and guiding sections, as well as a new and advantageous construction of elevating mechanism.

My invention also has for its object to provid e means for controlling the maximum speed of the descent of the chair independently of the release-valve when the latter is operated.

To these and other ends the invention consists in certain improvements and combinations of parts, all as will be further described, the novel features being pointed out in the claims at the end of the specification.

In the drawings, Figure 1 is an enlarged cross-sectional view through the base and operating portions of a dental chair constructed in accordance with my invention. Fig. 2 is a similar view showing the parts in the elevated position. Fig. 3 is a horizontal sectional view on the line 3 3 of Fig. 2. Fig. 4 is a similar view on the line 4 4* of Fig. 2. Fig. 5 is a similar sectional View on the line 5 5 of Fig. 2. Fig. 6 is a vertical sectional view on the line 6 6 of Fig. 1. Fig. 7 is a sectional view on the line 7 7 X of Fig. 6.

.Similar reference-numerals in the-several figures indicate similar parts.

1n illustrating my invention 1 have shown it applied to a dental chair embodying the hollow base or support 1, in which is mounted a revoluble section 2, supported upon an annular flange 3 and provided with suitable means for supporting a chair, whereby the latter may be elevated, 'as desired. Arranged within the section 2 is a vertically-movable cylindrical guide section or standard 4, guided in an adjustable collar or bushing 5 and also (N0 model.)

provided with outwardly-extending lugs or cars 6, embracing and movable longitudinally upon guide-rods 7, supported between lugs or cars 8 on said section. Similar guide-rods 9 are also provided upon the interior of the guide -section 4," and movable thereon is a block 10, attached to the lower end of an elevating member 15, connected to the chair, only a portion of the frame of which is shown and indicated by 16. The member 15 is preferably cylindrical, and as its upper end projects above the top of the section 4 it is guided in der 18, arranged within the section 2, as shown in Fig. 1; but as said cylinders operate independently of each other to elevate the chair they are provided with suitable pistons operated by fluid supplied from a pump. The latter embodies the cylinder 20, having a piston or plunger 21 therein adapted to be operated vertically by a pin or finger 22, attached to an oscillatory shaft 23, operated by a foot-lever 2 L, arranged exteriorly of the base. The piston is retracted and held in its normal position, as shown in Fig. 1, by a coil-spring 25, the lower end of which is provided with a plug having a screw or stud 11, provided with a head 12, adapted to engage a recess in the lower side of a slotted laterally-projecting lug 13 on the pitman 19. At its upper end the spring 25 is provided with a plug, as shown, into which extends the threaded end of a bolt 31, the head of which engages the exterior of the sec tion 2, permitting the tension of the spring to be adjusted by the application of a suitable tool. By loosening the bolt 31 the spring may be lowered and the head 12 of the stud 11 released from the aperture, affording a simple means of attachment, whereby the spring may be easily removed from the pitman if for any reason it is desirable to do so. The cylinder 18 is supported upon a frame or spider 26, secured to the bottom of the section 2 by bolts 27, as shown in Figs. 5 and 6, on which is also conveniently mounted the pump mechanism and the pressure-release valve and regulator, to be further described. The latter devices and the pump mechanism are connected with the cylinder 18 by passages 28 and 29, respectively.

The pistons in the stationary and movable cylinders are connected by means of a member 14, having at itslower end the piston-head formed by cups or washers 30, removably secured in position by a tubular bolt 35, and also provided on said end of the member 14 is an outwardly-extending flange or projection 36, adapted when the member is moved outwardly to engage a collar 37, located within the cylinder 18 and at the upper end thereof. At the upper end of the member exterior] y of the stationary cylinder 18, but arranged within the elevating member 15, is a piston-head formed by washers or cups 38, secured by the tubular bolt 39, and located at the inner side of said head is a collar 40, having thereon a projection or flange 41, similar to the flange 36, adapted to engage a hollow nut 42, arranged upon the lower end of the elevating member or cylinder 15, preventing its being withdrawn or forced ofl' from the end of the member 14.

43 indicates a coil-spring mounted in a recess in the bolt 39 and adapted to be engaged by the upper end or head 44 of the movable cylinder or elevating member when the latter descends to prevent the chair from jarring when it is arrested at the limit of its downward movement, and, if desired, a similar spring may also be provided in the bolt 35.

As the operating liquid or fluid is supplied to both cylinders from the same pump, I connect them by means of a passage 45 in the connecting member 14, which also leads through the bolts or screws 35 and 39, forming a conduit for the liquid.

The releasevalve before mentioned consists of the valve-stem 50, having the head 51 engaging the seat 52 to control the outflow of liquid from the passage 29, said stem being normally held in the closed position, as shown in Fig. 1, by means of the lever 53, operated by a spring-actuated plunger 54. The outer end of the lever is provided with a treadle 55, whereby the tension of the spring may be removed, permitting the stem to be raised and the valve opened by the force or pressure of the liquid in the passage. The end of the passage 29 extends beyond the valve-seat 52, as indicated by 129, and its extremity terminates in a conieally-shaped valve-seat 56,With which cooperates a head 57 on a stem 58. The latter is provided with a screw-thread 59, and its upper end extends to the exterior of the casing, permitting the area of the discharge-aperture to be easily regulated. This construction enables the speed of the outflowing liquid emitted when the regulator or valve is opened to be governed, thereby permitting the maximum speed with which the chair descends to be controlled independently of the release-valve, but without interfering with the operation of the latterif it is desired to allow the chair to descend at a slower rate of speed.

By providing a regulator valve arranged independently of the release-valve the latter may be opened to its full extent each time it is operated, thus permitting an y sediment carried by the oil or other liquid to be carried beyond the valve-seat, preventing it from becoming lodged thereon to interfere with the proper closing of the head 51. If this sediment is not forced through the regulator and becomes lodged therein, the only effect it may have will be to further retard the descending movement of the chair when the release-valve is opened; but by adjusting the stem 58 the regulator-valve may be opened and the passage cleared of any obstruction.

The operation of the chair will be readily understood by an inspection of the drawings in connection with the foregoing description. When the operator desires to elevate the chair, the piston 21 in the pump-cylinder 20 is operated by means of the operating-lever 24, the oil or other liquid being drawn from the interior of the base and forced through suitable check-valves into the supply-passage 28, leading to the bottom of the cylinder 18. The parts being in the lowered position, the fluid passes through the passage or conduit 45 into the elevating member or movable cylinder 15, causing the latter to be elevated until it is arrested at the limit of its relative movement on the guide section or standard 4 by the engagement of the block 10 with the lugs supporting the upper end of the guide-rods 9. During this upward movement the hollow nut 42, which forms an abutment in the movable member, engages the flange or projection 41 on the member 14, carrying the latter with the eyl inder 15. The upward movement of the guidesection is limited by the ears 6 thereon engaging the lugs 8. If during the upward movement of the cylinder 15 the member 14 is not fully extended from the cylinder, the projection 36, engaging the nut 37 in the stationary cylinder, will prevent said member from being withdrawn therefrom. When it is desired to lower the chair, the lever 53 is operated to allow the release-valve to be opened by the pressure of the fluid in the passage 29, which is permitted to escape into the passage 129 and to flow outwardly therefrom at a greater or less speed, according to the adjustment of the regulator-valve.

The hydraulic operating mechanism I have described embodying the relatively stationary and movable cylinders arranged so that one part telescopes within the other permits a wide range of adjustment to be obtained with but few parts, thus simplifying the construction and materially reducing the cost of manufacture.

I claim as my invention 1. The combination with a base, and a stationary cylinder, of an elevating cylinder adapted to support a chair, provision for guiding said elevating-cylinder, movable connected pistons in the cylinders, a conduit connecting the latter and a pump for supplying liquid to the cylinders.

2. The combination with a base, a guidingsection therein and a stationary cylinder, of an elevating-cylinder adapted to support a chair and connected pistons movable in both cylinders, a conduit connecting the latter and a pump for supplying liquid to one of the cylinders.

3. The combination with a base, a guidingsection therein and a stationary cylinder in the base, of a cylinder movable vertically in the guiding-section adapted to support a chair, pistons arranged in each cylinder, a rigid connection between the pistons, means for limiting the relative outward movement of the latter in the cylinders and a passage connecting the cylinders leading through the pistons and a pump for supplying liquid to the cylinders.

4:. The combination with a base, a verticallymovable guiding-section and a stationary cylinder, a vertically-movable cylinder in the standard-section and a tubular conduit having piston-heads arranged in the two cylinders, means for limiting their movement therein and a pump for supplying liquid to the cylinders.

- 5. The combination with abase, a guidingsection therein and an elevating-section movable therein and forming a cylinder,of a stationary cylinder, rigidly-connected pistons in the two cylinders, a conduit connecting the latter and a pump for supplying liquid to the cylinders.

6. The combination with a base and aguiding-seetion, of astationary cylinder, an elevating-cylinder adapted to support a chair and a tubular member arranged in each cylinder having projections on its ends and abutments' in said cylinders adapted to cooperate with the projections, piston-heads on the ends of the member and a pump attached to one of the cylinders.

7. The combination with a base, a guidingseetion and a stationary cylinder in the base, of a hollow elevating-section adapted to support a chair and movable relatively to the guiding-section and adapted to surround the cylinder when in the lowered position, pistonheads arranged in the cylinder and in the elevating-section and a member connecting said heads having a passage therein and a pump connected to the cylinder.

8. The combination with a base,avertically movable support and a cylinder having a piston, means for supplying a fluid to the cylinder and a conduit leading therefrom, of a valve arranged intermediate the ends of the conduit for normally closing the passage therein, and means for operating the valve, the discharge end of said conduit extending laterally from the valve whereby sediment carried by the fluid beyond the valve will be prevented from lodgment thereon, and means for regulating the discharge area of said passage.

9. The combination with a base, a movable the cylinder, a conduit leading therefrom, a

valve normally closing the passage in said conduit and devices for operating the valve, of a laterally-extending d ischarge-conduit leadin g from the valve and means for regulating the discharge area of the passage therein.

10. In a dental chair, the combination with abase, a pump having a plunger and a pitman, of a slotted projection on the pitman, a spring for operating the pitman in one direction and a headed stud secured to the spring and adapted to be engaged in the projection.

11. In a dental chair, the combination with a base, a pump having a plunger, a pitrnan and a slotted projection thereon having a recess in one side, of a spring attached to the base, a plug in the spring and a stud on said plug adapted to project through said slot and provided with a head adapted to lie in the recess in said projection.




Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2546904 *Dec 20, 1945Mar 27, 1951Weber Dental Mfg CompanyFluid operated safety jack apparatus
US3143332 *Feb 23, 1962Aug 4, 1964Watlington Lee SHydraulic lift support for chair
US3188136 *Aug 27, 1962Jun 8, 1965Emil J Paidar CompanyElectro-hydraulic system for operating elevatable chairs
US4643630 *Sep 7, 1984Feb 17, 1987Honda Giken Kogyo Kabushiki KaishaHeavy-object loading jig
US5738318 *Jun 7, 1996Apr 14, 1998Haworth, Inc.Chair with vertically shiftable height adjustment
Cooperative ClassificationF16H61/4139, B60K17/105