US3477761A - Dental chair headrest - Google Patents

Description

Nov. 11, 1969 J. D. KRANTZ 3,477,761

DENTAL CHAIR HEADREST Filed March 6, 1968 ATTOR E YS UnitedStates Patent 'O U.S. Cl. 297-409 3 Claims ABSTRACT oF THE DrscLosURE An improved headrest structure is provided for coupling to the upper end f the backrest of a reclining type dental chair. The headrest includes an elongated bar extending from the end of the dental chair backrest and terminating in a journal. A yoke assembly is pivoted to the journal at one end portion and serves to additionally pivot a headrest assembly at its other end portion. Dual pivotal action can thus take place about two parallel spaced horizontal axes, the configuration being such that no part of the bar, yoke assembly, or headrest will extend below the plane dened by the back surface of the dental chair backrest thereby eliminating obstructions to a dentists legs when seated in a position to work on a patient when the backrest is inclined.

This invention relates to dental equipment and more particularly to an improved headrest for reclining type dental chairs.

Many diiferent types of headrest structures for dental chairs are known and presently available. The primary requisite of such structure is that suitable linkages be provided such that the headrest may be moved to support a patients head relative to the dental chair backrest in a proper position to facilitates treatment. Since patients vary in size and since particular treatmentsjrequire differing positions of a patients head, the headrest should be capable of adjustment in several dimensions. Thus, the distance of the headrest from the upper end of the backrest of the dental chair should be adjustable; the level of the headrest above the plane of the backrest of the dental chair should be adjustable; and the angulation of the supporting cushion portions of the headrest should be adjustable for maximum comfort to the patient.

These particular adjustments are normally provided in headrests heretofore available but in all instances, the necessary linkages or articulated structures project below the plane of the back surface of the backrest of the dental chair. There are many instances in which a dentist works on a patient when the backrest of the dental chair is inclined almost to a horizontal position and wherein the dentist himself will be seated on a small chair or stool with his legs extending under the backrest. `In these cases, the dentists legs often encounter the downwardly projecting linkage structure for the headrest and in fact it is very dicult for the dentist to assume a comfortable seated position without his knees or other portions of his legs interfering with this headrest structure. Not only can accidental encounters with this structure by the dentists legs or knees result in painful bruises to the dentist, but in addition the structure itself can be inadvertently moved thus moving the patients head with possibly disastrous results if a delicate operation is being carried out.

With the foregoing considerations in mind, it is a primary object of the present invention to provide a greatly improved dental chair headrest in which the foregoing problem is overcome.

More particularly, it is an object to provide a dental chair headrest so designed as to be capable of 'assuming all of the necessary positions for accommodating various ICC sized patients and yet having no structural portions which extend below the plane of the back surface of the backrest of the dental chair so that this area is free of any obstructions to the end that a denist may be comfortably seated while working on a patient.

A more general object of this invention is to provide an improved dental chair headrest incorporating a minimum number of structural components for achieving the heretofore mentioned objects so that economy in manufacture and maintenance is realized.

Briefly, these and other objects and advantages of this invention are attained by providing an elongated support bar receivable within a suitable slot opening in the upper end of the backrest of a dental chair. The extending end of this support rod terminates in a journal for pivoting a first end portion of a yoke assembly. The second end portion of the yoke assembly in turn serves to pivotally support a headrest cushion member. The pivoting action takes place about first and second horizontal. axes which are spaced a given distance from each other, both of these `axes being disposed above the plane of the back surface of the backrest for the dental chair. In addition, the second pivot for the headrest cushion is disposed at a distance less than one-third the distance to the first pivoting structure.

With the foregoing arrangement, it is possible to readily adjust the position of the headrest cushion without any of the bar or yoke assembly structure extending below the plane of the backrest so that the various problems heretofore discussed are overcome.

A better understanding of the invention will be had by now referring to a preferred embodiment thereof, as illustrated in the accompanying drawings, in which:

FIGURE l is a fragmentary perspective view of the improved dental chair headrest of this invention;

FIGURE 2 is a fragmentary cross section taken in the direction of the arrow 2 2. of FIGURE l; and,

FIGURE 3 is a fragmentary cross section taken in the direction of the arrow 3-3 of FIGURE 2.

Referring first to FIGURE 1 there is shown a portion of a dental chair backrest 10 adapted to be inclined to nearly a horizontal position. Cooperating with this backrest is a headrest designated generally by the numeral 11. This headrest includes an elongated support bar 12 receivable within a suitable slot in the upper end of the backrest 10 in a position to extend from the backrest as shown. The extended end of the bar 12 terminates in a journal 13 defining a rst pivot structure for a yoke means designated generally by the numeral 14.

As shown, the yoke means 14 includes first and second arms 15 and 16 having initial portions held in parallel spaced relationship by a rigid cross bar 17. The initial portions of these arms straddle opposite ends of the journal 13 and are provided with suitable openings for receiving a manually rotatable knob and nut means 18 and 18' providing a pivot for this first end portion of the yoke. As shown, swinging action of th-e yoke can thus take place about a iirst horizontal axis A and the arms may be set in a desired position by simply tightening the knob 18.

'The initial portions of the arms from the journal 13 extend in laterally opposite horizontal directions and thence again extend in parallel spaced relationship with a greater spacing therebetween than the initial portions. These second ends of the arms are respectively pivoted to suitable brackets 19 and 20 constituting part of a headrest assembly. This assembly includes a headrest cushion 11a and an underside 11b to which the brackets 19 and 20 are secured. The arrangement is such that pivoting or swinging movement of the headrest cushion 11a can take place about a second horizontal axis designated B.

With particular reference to FIGURE 2, it will be evident that the distance between the underside 11b of the headrest assembly and the second horizontal pivot axis, designated d, is less than one-third the distance D between this second horizontal axis and the rst horizontal axis of pivoting through the journal 13. The relatively close pivotal relationship of the second end portion of the yoke means to the underside of the headrest assembly permits proper tilting of the headrest cushion without altering appreciably its translatory position from the upper end of the backrest 10. Moreover, this structure minimizes the possibilities of any portions of the headrest assembly extending below the plane of the back surface of the backrest 10. This plane is designated by the dashed line P in FIGURE 2.

In the cross section of FIGURES 2 and 3, the manner in which the support bar 12 is coupled to the backrest will be evident. As shown, there is provided a channel member 21 defining an elongated slot 22 in the end portion of the backrest 10. This slot runs parallel to the plane P and is dimensioned to receive the support bar 12.

In FIGURE 3 it will be noted that side edges of the support bar 12 include small detents such as indicated at 23 and 24. These detents cooperate with springloaded detent balls or equivalent indexing means as indicated at 25 and 26 formed in the sides of the channel so that the support bar 12 may be indexed to a desired position within the channel. This arrangement provides a very simple structure enabling the extent of the bar 12 from the end of the backrest 10 to be easily adjusted to thereby adjust the position of the headrest assembly from the back of the chairin accord with the height of a patient.

With the foregoing description in mind, the operation of the headrest of this invention will be evident. As mentioned in conjunction with FIGURES 2 and 3, the support bar 12 may initially be caused to extend from the end of the backrest 10 a desired distance to position the headrest cushion 11 in an approximate location depending upon the height of the patient for properly nesting his head. Next, the level of the cushion 11a above the backrest 10, that is, above the plane P may be adjusted by sw'mging the yoke assembly about the first horizontal pivot axis A shown in FIGURE l. After this height adjustment is made, the knob 18 is tightened to maintain the angle between the yoke and the support bar 12. While this adjustment may vary the extent or distance of the headrest assembly from the end of the backrest 10, compensation for any such change may readily be eifected by sliding the support bar 12 further out of or further into the channel 22.

Finally, the tilt angle of the headrest cushion 11a may be adjusted by rotating the headrest assembly about the second horizontal axis B of FIGURE 1 and in this respect, the friction of the second pivotal coupling to the brackets 19 and 20 is such as to retain the tilt angle of the headrest assembly in its set position. In FIGURE l, the headrest assembly is shown tilted backward to an unnatural position merely to enable clear illustration of the underside bracket structure and pivoting to th'e arms 1S and 16.

It will be clearly evident from an inspection of FIG- URE 2 that the various adjustments described can be effected without any of the bar, yoke, or headrest structure extending below the plane P. Thus a dentist may readily seat himself in a convenient position with his knees beneath the inclined back surface of the backrest 10 without any danger of his knees or legs encountering any obstructions.

From the foregoing description, it will thus be evident that the present invention has provided a greatly improved headrest for dental chairs wherein all of the various objects are fully realized.

What is claimed is:

1. For a dental chair having a backrest capable of inclining towards a horizontal position, a headrest comprising: an elongated support bar adapted to be coupled to said backrest in a position to extend a desired distance beyond the end of said backrest above the plane of the back surface of said backrest; a yoke assembly including first and second arms held in xed relationship to each other, initial portions of said arms being pivotally mounted to the extended end portion of said bar for swinging movement about a first horizontal axis disposed above said plane, said arms then extending laterally in outward directions from each other and thence into arm portions in parallel relationship at an increased spacing from each other; a headrest pad assembly including a cushion having an underside; and rst and second L-shaped brackets secured to said underside at a spacing to pivotally connect respectively to said arm portions for swinging movement about a second horizontal axis spaced a given distance from said first horizontal axis at a level above said plane, the distance between said underside of said cushion and second horizontal axis being less than one-third said given distance between said irst and second horizontal axes such that said headrest pad assembly may be positioned at any desired point above said plane relative to said backrest without any portions of said bar or yoke assembly projecting below said plane.

2. The subject matter of claim 1, in which said extended end portion of said bar terminates in a journal disposed between the initial ends of said arms; and a manually operable knob and nut means passing axially through said journal and openings in said initial portions of said arms to define a pivot axis coincident with said iirst horizontal axis and enable frictional retention of said arms in a set position by tightening of said knob.

3. The subject matter of claim 1, in which said end of said backrest includes an elongated channel running parallel to said plane for receiving said bar, side edges of said bar including detents and side edges of said channel including detent means for indexing with said detents to hold said bar in selected longitudinal positions in said channel.

References Cited UNITED STATES PATENTS 1,763,294 6/ 1930 Emmert 297-410 1,930,867 10/1933 West 297-408 2,190,395 2/1940 Brady 297-409 X 3,300,249 1/ 1967 Schneider 297-408 CASMIR A. NUNBERG, Primary Examiner U.S. C1. X.R. 297-403, 410

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