U.S. patent number 3,885,831 [Application Number 05/436,140] was granted by the patent office on 1975-05-27 for close-coupled articulating headrest.
Invention is credited to Keith O. Rasmussen.
United States Patent |
3,885,831 |
Rasmussen |
May 27, 1975 |
Close-coupled articulating headrest
Abstract
An articulating headrest for treatment chairs such as dental
chairs, to adapt such chairs for use in procedures with the dentist
seated. An adapter bracket mounts the headrest to the existing
structure of the chair and slideably receives a tongue member which
bears the balance of the headrest. A link is pivotally attached
both to the upper end of the tongue and to a cushion support plate
carrying a cushion for the patient's head, and both pivot points
are clamped by a single clamp mechanism. The combined motions of
sliding the tongue in the bracket and pivoting the cushion support
plate and the link about the pivot points allow selection of a wide
variety of headrest positions for upper jaw work, pediatric
dentistry, X-ray, and procedures with the dentist seated and the
patient reclining.
Inventors: |
Rasmussen; Keith O. (San
Francisco, CA) |
Family
ID: |
23731266 |
Appl.
No.: |
05/436,140 |
Filed: |
January 24, 1974 |
Current U.S.
Class: |
297/410;
297/405 |
Current CPC
Class: |
A61G
15/125 (20130101); A47C 7/38 (20130101); A61G
2210/50 (20130101) |
Current International
Class: |
A47C
7/36 (20060101); A47C 7/38 (20060101); A61G
15/12 (20060101); A61G 15/00 (20060101); A47c
003/00 (); A47c 007/48 () |
Field of
Search: |
;297/391,405-410 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Nunberg; Casmir A.
Attorney, Agent or Firm: Schapp and Hatch
Claims
I claim:
1. A close-coupled articulating headrest system for treatment
chairs and the like, comprising
a tongue member adapted for longitudinally adjustable engagement
with the back of the chair,
a link member pivotally attached at one end thereof to said tongue
member,
a dished cushion support plate pivotally attached adjacent the
upper edge thereof to the end of said link member opposite said
tongue member, and
overcenter toggle clamp means adapted for simultaneous releasable
locking of pivotal motion of said link member both with respect to
said tongue member and with respect to said cushion support
plate.
2. A close-coupled articulating headrest system as described in
claim 1 and wherein said link member is attached to said tongue
member adjacent the pivotal end of said tongue member, the distal
portion of said tongue member being engageable with the back of the
chair and having a retaining means thereon for locking said
longitudinal adjustment.
3. A close-coupled articulating headrest system as described in
claim 1 and wherein said clamp means comprises a unitary mechanism
having a clamp handle operative to clamp both pivotal motions by a
single motion of the clamp handle to a clamping position lying flat
against said link member, said clamp means being formed so that
said clamp handle projects angularly away from said link member
when said clamp means is released.
4. A close-coupled articulating headrest system as described in
claim 3 and wherein said clamp means includes split bearings as the
pivotal attachment of said link member to said tongue member and
the pivotal attachment between said tongue member and said cushion
support plate, a tension rod connected between said split bearings
simultaneously, said tension rod being operatively connected to
said clamp handle for clamping and unclamping movement thereby.
5. A close-coupled articulating headrest system as described in
claim 4 and wherein said split bearings are formed integrally in
the opposite ends of said link member, and said split bearings are
journaled on pins secured against rotation in said tongue member
and said cushion support plate.
6. A close-coupled articulating headrest system as described in
claim 1 and wherein the axis of pivotal motion of said cushion
support plate with respect to said link member is located adjacent
the plane in which said cushion support plate generally lies.
7. A close-coupled articulating headrest system as described in
claim 6 and wherein the end of said link member attached to said
cushion support plate is curved forward toward said cushion support
plate and said cushion support plate has relieved areas thereon
cooperative with said link member, whereby the axis of pivotal
motion between said link member and said cushion support plate is
brought into close juxtaposition with the plane generally occupied
by said cushion support plate.
8. A close-coupled articulating headrest system as described in
claim 1 and wherein the axis of pivotal motion of said link member
with respect to said tongue member is adjustably disposable
adjacent said cushion support plate.
9. A close-coupled articulating headrest system as described in
claim 8 and wherein the end of said link member attached to said
tongue member is curved forward in the direction to bring it toward
the cushion support plate when that plate is disposed adjacent the
axis of pivotal motion between said link member and said tongue
member.
10. A close-coupled articulating headrest system as described in
claim 8 and wherein the pivotal end of said tongue member is
attached to a bracket which is in turn pivotally connected to said
link member, said bracket being curved forward in the direction to
bring it toward the cushion support plate when that plate is
disposed adjacent the axis of pivotal motion between said link
member and said tongue member.
11. A close-coupled articulating headrest system as described in
claim 8 and wherein the axis of pivotal motion of said cushion
support plate with respect to said link member is located adjacent
the plane in which said cushion support plate generally lies.
12. A close-coupled articulating headrest system as described in
claim 11 and wherein the end of said link member attached to said
cushion support plate is curved forward toward said cushion support
plate and said cushion support plate has relieved areas thereon
cooperative with said link member to bring the axis of pivotal
motion therebetween into close juxtaposition with the plane
generally occupied by said cushion support plate, and the pivotal
end of said tongue member is attached to a bracket which is in turn
pivotally connected to said link member, said bracket and the end
of said link member attached to said bracket both being curved
forward in the direction to bring them toward the cushion support
plate when that plate is disposed adjacent the axis of pivotal
motion between said link member and said tongue member, said
headrest system further comprises a flattened head cushion
attachable to said cushion support plate.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a CLOSE-COUPLED ARTICULATING
HEADREST, and more particularly to headrests for a dental chair or
similar treatment chair yielding a thin-profile configuration for
operative techniques in which the patient's head is disposed
adjacent the dentist's lap.
Conventional dental chairs such as the older chairs manufactured by
the Ritter, Weber, and S.S. White companies are generally
constructed with a unitary back cushion and either a single curved
pad or a bifurcated two-pad headrest, with both the back cushion
and the headrest mounted on a common back support member. A linkage
allows adjustment of the headrest position in some models, but in
all models, the depth of the headrest and linkage in the direction
generally perpendicular to the plane of the back cushion makes it
difficult for the dentist to operate while seated alongside a fully
reclining patient.
Among the desirable qualities of a satisfactory headrest for dental
chairs of this type are adaptability to a wide range of procedures
and adjustability to all sizes of patients, both adults and
children. Prior art headrests have suffered from a lack of
flexiblity in both respects, and, indeed, separate devices were
often required to adapt the chair for children.
SUMMARY OF THE INVENTION
The close-coupled articulating headrest of the present invention
replaces the conventional headrest apparatus on a treatment chair
such as a dental chair, to adapt it to a wider range of uses,
including dentistry with the patient fully reclining with his head
above the dentist's lap. The headrest or "split back" of this
application provides a thin profile of the back of the dental chair
to allow such "sit-down" dental operations and also permits full
articulation of the headrest position without sacrifice of the thin
profile.
The close coupling possible with the headrest allows the patient to
be positioned with head thrown back for upper jaw work, or with the
head raised from the plane of the back of the chair, as is
necessary for certain X-ray procedures. It also allows the head
cushion to be swung down flat against the front of the back cushion
to "shorten" the chair for children, all without projecting too far
to the rear of the chair to interfere with use with the patient
fully reclined and the dentist seated.
As discussed at greater length in my co-pending applications, Ser.
Nos. 383,452 and 384,013, filed July 27, 1973 and July 30, 1973,
respectively, both entitled SPLIT BACK DENTAL CHAIR APPARATUS, the
headrest may be provided either as part of the original equipment
of a new treatment chair, or as a kit for conversion of older
chairs. For the latter purpose, the bracket which receives the
longitudinal tongue of the headrest is made adaptable to several
configurations of backs and back support members of conventional
chairs, as shown in those applications so that the installation may
be made with minimal modification of the existing chair.
Accordingly, it is a principal object of the present invention to
provide an articulating headrest for dental chairs and the like
which yields a thin longitudinal profile of the chair to permit
dental operations with the patient's head above the dentist's
lap.
It is a further principal object of the present invention to
provide an articulating headrest of the character described which
provides a wide range of positions without sacrifice of the thin
profile.
Yet another principal object of the present invention is to provide
an articulating headrest of the character described which may be
adapted to a wide range of existing models of dental chairs without
extensive alterations.
Still another object of the present invention is to provide an
articulating headrest of the character described which effectively
"shortens" the chair for pediatric dentistry.
A still further object of the present invention is to provide an
articulating headrest of the character described which may be
adjusted to elevate the patient's head above the plane of the back
of the chair for certain procedures.
It is another object of the present invention to provide an
articulating headrest of the character described which is adaptable
for upper jaw work on a reclining patient.
Further objects and advantages of the present invention will become
apparent as the specification proceeds, and the new and useful
features thereof will be fully defined in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred form of the present invention is illustrated in the
accompanying drawings, forming part of this specification, in
which:
FIG. 1 is a perspective view of the close-coupled articulating
headrest of the present invention, shown attached to a portion of
the back of a dental chair, with dashed lines and circular arrows
indicating the axes of pivotal motion of the headrest and the
motion about those axes;
FIG. 2 is a side elevational view of a typical prior art dental
chair apparatus, with the lower portions thereof shown broken
away;
FIG. 3 is a series of side elevational views, on a reduced scale,
of the headrest of the present invention attached to the back of a
dental chair, with the lower portions of the chair shown broken
away, illustrating four different positions of adjustment of the
headrest;
FIG. 4 is a rear elevational view, on an enlarged scale, of the
headrest of the present invention, with the lower portion thereof
broken away;
FIG. 5 is a cross-sectional view taken approximately along the
plane of lines 5--5 of FIG. 4;
FIG. 6 is an exploded perspective view on a reduced scale of the
headrest of the present invention, corresponding to the upper
portion of FIGS. 4 and 5; and
FIG. 7 is a fragmentary cross-sectional view on an enlarged scale,
taken approximately along the plane of lines 7--7 of FIG. 1.
While only the preferred form of the present invention has been
shown here, it should be understood that various changes and
modifications may be made, within the scope of the claims attached
hereto, without departing from the spirit of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, there is shown in FIG. 1 the
back 11 of a dental or treatment chair having a close-coupled
articulating headrest system generally indicated at 12. The
headrest system 12 includes a tongue member 13 adapted for
longitudinally adjustable engagement with the back 11 of the chair,
a link member 14 pivotally attached at one end to the tongue member
13, and a cushion support plate 16 pivotally attached to the
opposite end of the link member 14. The cushion support plate 16 is
attached to the link member 14 at a point adjacent one edge of the
plate 16, and a clamp means generally indicated at 17 is provided
for releasable clamping of the pivotal motion of the link member 14
both with respect to the tongue member 13 and with respect to the
plate 16.
The pivotal end of the tongue member 13 bears a yoke bracket 18,
with a short rod 19 serving as an axle passing through both arms of
the yoke. The lower end of the link member 14 is formed into a
split bearing 21, journalled about the rod 19. The rod 19 has
flattened areas at each end (see FIG. 6) for engagement by a pair
of screws 22 in the arms of the yoke bracket 18, so that it is held
both against rotation and longitudinal motion. The lower, or
distal, end of the tongue member 13 is engaged in a keyway or slot
23, shown here as forming a part of the back support member 24 of
the chair. The tongue member 13 slides longitudinally in the keyway
23, and is secured at the desired longitudinal position by a
retaining means, shown here as a knob 26 threaded through the lower
end of the tongue member 13.
The knob 26 when tightened bears against the right hand side of the
keyway, as shown in FIG. 7, to clamp the tongue member 13 against
the opposite face of the keyway 23. A slot 27 in that opposite face
of the keyway 23 allows a range of longitudinal motion for the knob
26. Although a knob 26 serves as the retaining means in the present
embodiments, other means such as the ratchet and pawl mechanisms
shown in my above-cited applications may likewise be used. Also,
with chairs in which the back support member 24 is not itself
suitable for receiving the tongue member 13, the tongue member 13
may be received by an adapter which is in turn received either by
the back support member 24 or secured directly to the back 11 of
the chair, as is also shown in my above-cited applications.
At the end of the link member 14 opposite the first split bearing
21 is a second split bearing 28, which journals a second short rod
29, similar to the short rod 19. As with the rod 19, the rod 29 has
flattened ends, which are held by screws 31 against the shoulder
areas 32 formed in the cushion-receiving side of the cushion
support plate 16. The rod 29 thus forms a fixed axle for the
pivotal motion of the link member 14 and the plate 16 with respect
to each other.
The two split bearins 21 and 28 are both clamped by a single
unitary clamp means 17, which includes a tension rod 33 passing
through both of the jaws formed by the slot 34 in the split bearing
21. The tension rod 33 also passes transversely at an angle through
the jaws formed by the slot 36 in the upper split bearing 28. The
body of the link member 14 has a longitudinal trough 37 cut into
its rearward side and running most of the length of the link 14,
including both jaws of the upper split bearing 28, and the tension
rod 33 passes longitudinally through the trough 37.
The uppermost jaw of the split bearing 28 is formed into a yoke 38
by the passage of the trough 37 through it. A pin 39 passes through
the arms of the yoke 38 and journals a handle 41 by passing in turn
through the arms of a yoke 42 formed by slotting the upper end of
the handle 41. The arms of the yoke 42 project upward and forward
beyond the pin 39, as shown in FIG. 5, a short distance to receive
a pin 43. The pin 43 passes through the upper end of the tension
rod 33, so that counterclockwise movement of the handle 41 draws
the tension rod 33 upward. The tension in the tension rod 33 draws
head 44 on the lower end of the rod 33 upward against the lower jaw
of the split bearing 21 to draw that jaw upward to clamp motion
about the axle 19. At the same time rod 33 transmits tension
through the pin 39 to the upper jaw of the split bearing 28 to
clamp motion about the axle 29.
The clamp 17 remains taut due to the toggle-type movement provided
by the pins 39 and 43 and the arms of the yoke 42. The pin 43 need
not, however, pass "over-center" with respect to the pin 39, as the
friction in the parts is sufficient to offset the small transverse
forces produced by the tension in the rod 33 when the pin 43 is
near the over-center point.
The cushion support plate 16 is of somewhat rounded trapezoidal
shape as shown in elevation in FIG. 4, and is slightly concave in
form as shown in the cross-sectional view of FIG 5. As may be seen
from FIG. 5, the axis of pivotal motion of the plate 16 with
respect to the link 14, i.e. the axis of the rod 29, lies generally
within the plane of the plate 16. This configuration is produced
both by the forward curve (to the right in FIG. 5) of the upper end
of the link member 14 and the releif formed in the back of the
plate 16 by a trough 46 lying between the reinforcing ribs 47 and
by the relatively deeply vertically cut relieved area or slot 48.
The point of attachment of the plate 16 to the link 14, via the
axle 29, is located adjacent the top edge of the plate 16 to make
possible the wide range of positional adjustments, some of which
are shown in FIGS. 3A, 3B, 3C, and 3D. Together with the location
of the axis of movement of the plate with respect to the link
adjacent to or within the plane of the plate itself, the location
of that axis near one edge of the plate makes possible certain
positionings of the headrest which are clearly out of the question
with the prior art headrests, such as that shown in FIG. 2. For one
example, the close coupling of the link upper end and the head
supporting surface in the present invention allows the positioning
shown in FIG. 3D for shorter adult and juvenile patients, while the
remoteness of connection between the link and the head supporting
surface make that configuration impossible in the prior art device
shown in FIG. 2. In that prior art device, the length of the arm 53
places a substantial distance between the head supporting surface
51 and the upper axle 54.
As may be seen from FIG. 5, the headrest of the present invention
also has the lower axis of motion, that between the link 14 and the
tongue 13 about the axle 19, so positioned that it may be brought
into a closely adjacent relation to the cushion support plate 16
when that position is desired. Part of this positioning is made
possible by the forward curve of the lower end of the link 14 and
part by the forward curve of the upper end of the bracket 18 (i.e.,
to the right as viewed in FIG. 5). It can be appreciated by
inspection of FIG. 2 that it is not possible to bring the head
supporting surface 51 of the prior art headrest into juxtaposition
with or even near the lower axle 56, and the typical curve of the
bracket 57 is precisely the opposite of that of the present
invention.
As may be seen from FIG. 3A through D, the ability to bring the
axes of motion into close juxtaposition with the head supporting
surface is important both in producing the flexibility of positions
of adjustment of the present headrest, and in yielding the thin
profile, particularly as shown in FIGS. 3A and 3B, and also to an
extent in FIG. 3D. This thin profile permits the dentist to operate
on a reclining patient while seated with the patient's head
immediately above the dentist's lap. Due to the lack of
close-coupling in the prior art mechanism shown in FIG. 2, the
mechanism will protrude a considerable distance below the back of
the chair when the chair is used in a reclining position, and thus
prevent the dentist from operating comfortably on the patient while
seated alongside. The structure of the present invention protrudes
a minimum depth behind the back of the chair while elevating the
patient's head to approximately the level of the front of the back
cushion 11 of the chair. The positioning of the attachment of the
plate 16 to the link 14 adjacent one edge of the plate 16, the
positioning of the axis to lie in or adjacent to the plane occupied
generally by the plate 16, and the forward positioning of the lower
axis formed by the rod 19 all contribute to the production of a
very thin profile, while retaining the maximum flexibility of
positioning.
A head cushion 49 is attached to the cushion support plate 16 by an
appropriate technique. Preferably, and as here shown, the
attachment is made by adhering a strip 61 of fabric material, of
the type commercially available as Velcro, to the front surface of
the plate 16. If the material covering the cushion 49 is a twisted
loop material such as is often found in upholstery, it will serve
itself as a mating surface for engagement with the Velcro hook
material 61; if not, a mating strip of Velcro loop material may be
adhered or sewn to the rear side of the cushion 49.
In the illustration in FIG. 2 of the typical prior art headrest,
the handle for clamping motion of the headrest about the pivot
points is indicated at 58. Another handle 59 releases the bracket
57 from engagement with the keyway or slot in the back support
member 24 to permit longitudinal movement or the headrest or its
removal.
From the foregoing it may be seen that a close-coupled articulating
headrest has been provided which can adapt many present models of
dental and other treatment chairs to a wide range of headrest
positions while retaining the thin profile which permits "sitdown"
dentistry. Among the range of positions available are those
effective for upper jaw work, short patients, X-ray procedures and
orthodontic and prosthetic work, with the patient in fully reclined
or sitting up modes, at the option of the dentist, or without
requiring modifications of the chair structure to accommodate these
modes.
* * * * *