US3823979A

US3823979A - Dental chair

Info

Publication number: US3823979A
Application number: US00322756A
Authority: US
Inventors: R Davis
Original assignee: Den Tal Ez Manufacturing Co
Current assignee: DEN-TAL-EZ DENTAL PRODUCTS CORP A CORP OF PA; DENTAL-EZ Inc; Den Tal Ez Manufacturing Co
Priority date: 1973-01-11
Filing date: 1973-01-11
Publication date: 1974-07-16
Anticipated expiration: 1991-07-16

Abstract

A dental chair comprising a seat portion having a back portion pivotally secured thereto. A lever element is secured at its upper end to the lower center portion of the back portion and is pivotally secured at its lower end to the rearward end of a clevis element. The lever element is pivotally secured, above its lower end, to the seat portion. The forward end of the clevis element is secured to a sleeve which is threaded onto the screw shaft of an electric motor for longitudinal movement thereon. Movement of the sleeve by the screw shaft causes the clevis element to act upon the lower end of the lever element thereby causing the lever element and the back portion to pivot about the pivotal connection of the lever element and the seat portion.

Description

United States Patent 119 Davis, Sr.

[ 4] DENTAL CHAIR 75] Inventor: Roderick W. Davis, Sr., Des Moines, 1

Iowa

[73] Assignee: Den-Tal-Ez Mfg. Co., Des Moines,

Iowa

[22] Filed: Jan. 11, 1973 [21] Appl. No.: 322,756

[52] U.S. Cl. 297/330 [51] Int. Cl A47c 1/02, A47c 1/06, A470 H12 [58] Field of Search 297/330, 341, 342, 346, 297/347, 348, 317, 83, 71; 248/421, 3.93

[56] References Cited UNITED STATES PATENTS 3,331,997 5/1968 Fritz et a1. 297/330 3,578,379 5/1971 Taylor et a1. 297/330 3,588,170 6/1971 Knabusch 297/330 3,596,982 8/1971 Grams 297/330 July 16, 1974' 3,719,391 3/1973 Neri 297/330 v Primary ExaminerPaul R. Gilliam- 57 ABSTRACT A dental chair comprising a seat portion having a back portion pivotally secured thereto. A lever element is secured at its upper end to the lower center portion of the back portion and is pivotally secured at its lower end to the rearward end of a clevis element. The lever element is pivotally secured, above its lower end, to

the-seat portion. The forward end of the clevis element is secured to a sleeve which is threaded onto the screw shaft of an electric motor for longitudinal movement thereon. Movement of the sleeve by the screw shaft causes the clevis element to act upon the lower end of the lever'element thereby causing the lever element and the back portion to pivot. about the pivotal connection of the lever element and the seat portion.

' 9-Claims, 6 Drawing Figures 1 DENTAL CHAIR BACKGROUND OF THEINVENTION This invention relates to dental chairs and more particularly to the means for pivoting the back portion of the dental chair with respect to the seat portion. The seat backs of conventional dental chairs are comprised of a heavy frame which surrounds the seat back. The heavy frame is ordinarily constructed of cast metal and is extremely expensive. Further, the conventional dental chairs do not have a simple but efficient means for controlling the pivotal movement of the back portion of the dental chair with respect to the seat portion.

Therefore, it is a principal object of the invention to provide an improved dental chair.

A further object of the invention is to provide a dental chair having means thereon for pivoting the back portion of the chair with respect to the seat portion of the chair.

A further object of the invention is to provide a dental chair having a back portion comprised of a hollow frame having plywood members and upholstery material mounted thereon.

A further object of the invention is to provide a dental chair having an electric motor associated therewith for pivotally moving the back portion of the chair.

A further object of the invention is to provide a dental chair having a novel means for pivotally connecting the back portion tothe seat portion of the chair.

A further object of the invention is to provide a dental chair which is economical in manufacture, durable in use and refined in appearance.

These and other objects will be apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS This invention consists in the construction, arrangements and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings, in which: 1

FIG. 1 is a perspective view of the dental chair of this invention;

FIG. 2 is a plan view as seen along lines 2 2 of FIG. 1 with portions thereof cut away to more fully illustrate the invention;

FIG. 3 is an enlarged sectional view seen along lines 3 3 of FIG. 2;

FIG. 4 is a sectional view similar to FIG. 3 except that the back portion has been pivotally moved upwardly with respect to the seat portion;

FIG. 5 is an exploded perspective view of the lever element and clevis element; and

FIG. 6 is an enlarged sectional 6 6 of FIG. 2.

DESCRIPTION'OF THE PREFERRED EMBODIMENT The numeral 10 refers generally to the dental chair of this invention comprising a seat portion 12 having a view seen along lines I back portion 14 pivotally secured thereto. Seat portion Motor 26 is operatively secured to the brace 20 and has a horizontally extending screw shaft extending rearwardly therefrom. Sleeve 30 is threadably mounted on shaft 28 for longitudinal movement thereon. The numeral 32 refers to a clevis element having forwardly ex- I tending

arms

34 and 36 which are secured to sleeve 30 by pins 38. Clevis element 32 includes a rearward end portion 40 which is slightly offset with respect to the

arms

34 and 36 and which is positioned in a plane below the

arms

34 and 36. Clevis element 32 also includes a pair of rearwardly extending arms 42 and 44.

The back portion 14 is comprised of a hollow frame 46, a front layer of plywood 48, a rear layer of plywood 50, a detachable back panel 52, and an upholstered gitudinally moved on the screw shaft 28 thereby causing clevis element 32 to act upon the lower end of lever element 58 at 66 to" pivot the back portion 14 about 64.

Limit switches

68 and 70 are mounted on the frame 16 in the movable path of arm 72 which is secured to clevis element 32. The

limit switches

68 and 70 are electrically connected to motor 26 to deactivate the same at the extreme limits of travel of the sleeve 30 to prevent damage to the various components.

It can be seen from the foregoing that back portion 14, due to the construction thereof, is much more economical to manufacture than existing dental chairs. It canalso be seen that the novel means for pivotally moving the back portion 14 with respect to the seat portion 12 represents a distinct improvement in the art.

' The design relationship between the lever element 58,

a seat portion comprising a frame means and having rearward and forward end, a back portion having upper and lower ends, anelectric motor secured to said frame means having a rearwardly extending screw shaft, a member'threadably mounted on said screw shaft for longitudinal movement thereon, a clevis element having rearward and forward ends said clevis element having a first pair of spaced apart arms at its forward end secured to said member, and a second pair of spaced apart arms at its rearward end,

a lever element having upper and lower ends, the upper end of said lever element being secured to said back portion, the lower end of said lever element being pivotally arms of the rearward end of said clevis element,

and means pivotally connecting said lever element above its said lower end to said frame means whereby activation of said motor will cause the rearward end of said clevis element to act upon the lower end of said lever element topivot said back portion about the pivotal connection between said lever element and said frame means.

2. The dental chair of claim 1 wherein said back portion comprises a hollow frame member having front and back panels secured thereto, said lever element being secured to said front panel.

secured to the spaced apart 3. The dental chair of claim 2 wherein said panel has an access opening provided therein in communication with said upper end of said lever element.

4. The dental chair of claim 1 wherein said second pair of arms dwell in a plane below said first pair of arms.

8. The chair of claim 1 wherein said clevis element has a limit switch actuating arm which deactivates said motor at the extreme limits of travel of said member threadably mounted on said screw shaft, thereby preventing damage to the components of said chair.

9. The chair of claim 8 wherein the rearward end portion of said .clevis element is slightly offset with respect to the forward end portion of said clevis element.

Claims

1. A dental chair comprising, a seat portion comprising a frame means and having rearward and forward end, a back portion having upper and lower ends, an electric motor secured to said frame means having a rearwardly extending screw shaft, a member threadably mounted on said screw shaft for longitudinal movement thereon, a clevis element having rearward and forward ends said clevis element having a first pair of spaced apart arms at its forward end secured to said member, and a second pair of spaced apart arms at its rearward end, a lever element having upper and lower ends, the upper end of said lever element being secured to said back portion, the lower end of said lever element being pivotally secured to the spaced apart arms of the rearward end of said clevis element, and means pivotally connecting said lever element above its said lower end to said frame means whereby activation of said motor will cause the rearward end of said clevis element to act upon the lower end of said lever element to pivot said back portion about the pivotal connection between said lever element and said frame means.

3. The dental chair of claim 2 wherein said panel has an access opening provided therein in communication with said upper end of said lever element.

5. The dental chair of claim 1 wherein said lever element comprises a plate means having an arcuate lower end portion.

6. The dental chair of claim 1 wherein a pair of spaced apart ears are secured to said frame means, said lever element being pivotally secured to said ears above its lower end.

7. The dental chair of claim 6 wherein said ears extend rearwardly and upwardly from said frame means.

9. The chair of claim 8 wherein the rearward end portion of said clevis element is slightly offset with respect to the forward end portion of said clevis element.