US 1548348 A
Description (OCR text may contain errors)
Aug; 4, 1925. 1,543,
F. E, CASE HEADREST,
Filed Aug. 30 1922 Shaw-Sheet 1 Patented Aug. 4, 1925.
FRANK E. CASE, OF CANTON; OHIO, ASSIGNOR TO TI-IE HARVARD COMPANY, OF CANTON, OHIO, A CORPORATION OF OHIO.
Application filed August 30, 1922. Serial No. 585,314.
To all whom it'meg concern:
Be it known that I, FRANK E. CASE, a citizen of the United States, residing at Canton, in the county of Starkand State ol Ohio, have invented certain new and useful Improvements in Headrests, of which the following is a specification.
The invention relates to head rests for dental chairs'and the like, comprising a bracket having diverging arms with rest pads mounted on-the ends thereof; and the object ofthe improvement is to provide a universal joint between the pads and the ends of the arms to permit a ready adjustment of the pads iir-all directions to lit the contour of a head, with yielding means for frictionally holding the pads in an adjusted position,
The invention is illustrated in the accom- 20 panying drawings forming part hereof, in
which Figure 1 is a perspective view of a dental chair showing the improved head rest;
Fig. 2, a rear elevation of the head rest and part of its supporting standard;
Fig. 3, a section of one of the pads on line 38, Fig. 2;
Fig. 4-, an inner side perspective view of pad detached from its supporting plate;
Fig. 5, a detached perspective view of one half of a supporting plate in section on line 33, Fig. 2;
Fig. 6, a detached perspective view of one end of a diverging arm;
Fig. 7, a detached perspective view of a journal bar; and
Fig. 8, a detached perspective view of a frictional spring.
vSimilar numerals refer to similar parts throughout the drawings.
The head rest may include a bracket 9 adjustably mounted on a standard '10 and having forwardly curved, diverging arms 11, with a rest pad 12 mounted on the free end of each arm.
The rest pads may each include a resilient packing 13 located between an annular frame 14 and a flexible cover 15, the edges 15 of which cover are preferably gathered around and under the periphery of the frame, and may be clamped between the same and the periphery of an annular supporting plate 16 by means of screws 17.
The supporting plates 16 may each be in the form of a slightly dished disk having an axial aperture 17, for receiving the spheri-' cal end 18 of a supporting bracket arm 11; and having open journal bearings 19 and 1.9 in its inner side at diametrically opposite sides of the axial aperture 1?, into which are seated the ends 20 of a trans verse journal bar 20.
The journal bar extends through a cylind ric cross bore 21 in the spherical head 18 on the supporting arms, and a ball 20 is formed on the bar intermediate its ends which bears in the cross bore. The diameter of the ball is the same as that of the cylindric bore and the diameter of the bar is substantially less than that of the bore; so that the bar can swing freely on the center of the ball in all directions within the limit ofthe end openings of the bore. The journal bar is preferably positioned in aplane inclined to the plane of the supporting disk.
A. conveuly protruding strip spring 22 is mounted on the inner side of the annular frame to extend across the same over the opening of the axial aperture in the supporting plate when the parts are assembled, so as to press yieldingly against the spherical head on the end of the supporting arm, as shown in Fig. 3, to frictionally hold the same in given position of adjustment.
The parts are readily assembled by inserting the spherical end of a supporting arm through and beyond the axial aperture in the supporting plate, and then inserting the bearing bar through the transverse bore of the spherical head, after which the same is withdrawn to seat the ends of the bearing bar in the journal bearings and the supporting plate is then secured to the frame of a pad with the strip spring in pressing contact with the spherical head of the supp0rting arm.
It is evident that the rest pad may be adjusted in various directions upon the supporting arm by a turning of the bearing ball within the transverse bore in the spherical head, as well as by a turning of the ends of the journal in the bearings in the sup porting plate; and that the yielding frictional pressure of the spring plate upon the spherical head of the supporting arm serves to hold the journal bar in. its seat, and also to hold the rest padin any given position of adjustment. without, however, interfering with a ready adjustment of the rest pad.
I claim: 1. A head rest including a restpad a supporting arm having a spherical head on its end with a cylindric cross bore therein,
and a transverse journal bar eatendin'g through the bore with its ends seated within the rest pad and having a ball intermediate its ends bearing in the bore the, diameter of a the bore being equal to that of the ball and substantially larger than that of the bar.
2. A head rest including a rest pad a supporting arm having a spherical head on its end with a eyli-ndric. cross bore therein, a.
transverse journal bar extending through the bore with its ends seated within the rest 3, A head rest including a supporting plate having an axial aperture therein with journal bearings at opposite sides thereof, a
rest pad secured to the plate, a supporting arm having a spherical head with a cylindric cross bore therein; and a transverse journal bar extending through the bore with its ends seated in the journal bearings and having a ball intermediate its ends bearing in the bore, the diameter of the bore being equal to that of the hall and substantially larger than that of the bar.
4., A head rest including a supporting plate having an axial aperture therein with journal bearings at opposite sides thereof, a rest pad secured to the p1ate, a supporting arm having a spherical head with a cylin dric. cross bore therein; a transverse journal har extending through the bore with its ends seated in the journal bearings and having a ball intermediate its ends bearing in the bore, the diameter of the bore being equal to that otthe ball and substantially larger than that of the bar and spring means in the pad bearing againstthe spherical head yieldingly holding the parts in adjusted position.
FRANK E. oAsn