U.S. patent number 3,813,147 [Application Number 05/296,094] was granted by the patent office on 1974-05-28 for dental apparatus.
This patent grant is currently assigned to Sybron Corporation. Invention is credited to Michael Edward Rick.
United States Patent |
3,813,147 |
Rick |
May 28, 1974 |
DENTAL APPARATUS
Abstract
Disclosed is a dental apparatus comprising a chair-instrument
tray combination, wherein the instrument tray is attached to the
articulating backrest of the dental chair so that the tray follows
the movement of the backrest. The support of the tray includes a
parallelogram linkage which maintains the tray horizontally
oriented as the backrest is moved between an upright and a reclined
position. The tray support also includes a leveling mechanism for
initially leveling the tray and adjusting it parallel to the true
horizontal independent of the chair itself. This is to compensate
for situations where the floor on which the chair rests is not
level.
Inventors: |
Rick; Michael Edward
(Rochester, NY) |
Assignee: |
Sybron Corporation (Rochester,
NY)
|
Family
ID: |
23140579 |
Appl.
No.: |
05/296,094 |
Filed: |
October 10, 1972 |
Current U.S.
Class: |
297/146 |
Current CPC
Class: |
A61G
15/14 (20130101); A47C 7/68 (20130101) |
Current International
Class: |
A47C
7/62 (20060101); A47C 7/68 (20060101); A61G
15/14 (20060101); A61G 15/00 (20060101); A47c
001/04 (); A47c 007/62 () |
Field of
Search: |
;297/191,146,163,61 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McCall; James T.
Attorney, Agent or Firm: Roessel; Theodore B. Aceto;
Roger
Claims
Having thus described the invention in detail what it is claimed as
new, is:
1. Dental apparatus comprising in combination:
a. a dental chair having a seat frame and a backrest frame, said
backrest being supported for deflection between an upright and a
reclined position;
b. a parallel motion linkage having a first portion supported by
said seat frame, and a second portion rotatable by said linkage in
concert with said backrest as the latter is deflected between an
upright position and a reclined position; and
c. a horizontally oriented tray member carried by said second
portion, said tray being maintained horizontally oriented by said
linkage as said second portion rotates in concert wtih said
backrest frame.
2. A combination as set forth in claim 1 including means for
rotating said second portion in concert with said backrest
comprising:
a. a guide plate on said backrest having a slot therethrough
extending generally parallel to said parallel motion linkage;
and
b. a guide pin fixed to said parallel motion linkage second portion
and extending slidably through said slot.
3. A combination as set forth in claim 2 wherein said guide plate
forms a wall of a recess in the side of said backrest, said
parallel motion linkage being generally located in said recess.
4. A combination as set forth in claim 1 including a horizontal
support arm pivoted to said parallel motion linkage second portion
for movement in a horizontal plane, said tray being carried by said
support arm.
5. A combination as set forth in claim 4 wherein said support arm
includes a parallel motion linkage capable of movement in a
vertical plane.
6. A combination as set forth in claim 1 including adjustable means
at said parallel motion linkage first portion operable through said
parallel motion linkage for adjusting said tray to a true
horizontal position independent of the level orientation of said
chair on the floor of a dental operatory.
7. A combination as set forth in claim 6 wherein said adjusting
means comprises:
a. a socket provided adjacent the rear of said seat frame;
b. a ball member adjustably positioned in said socket; said ball
having a upstanding member supporting said parallel linkage first
portion; and
c. lock means for fixing said ball in said socket in an adjusted
position.
8. Dental apparatus comprising in combination:
a. a dental chair having a seat frame and a backrest frame, said
backrest frame being supported for deflection between an upright
and a reclined position;
b. a parallel motion linkage having a first portion supported by
said seat frame and a second portion;
c. a guide plate on said backrest frame having a slot therethrough
extending generally parallel to said parallel motion linkage;
d. a guide pin fixed to said parallel motion linkage second portion
and extending slidably through said slot for rotating said second
portion in concert with said backrest frame as the latter is
deflected between an upright position and a reclined position;
and
e. a horizontally oriented tray member carried by said second
portion and being maintained horizontally oriented by said parallel
motion linkage as said second portion rotates in concert with said
backrest frame.
Description
BACKGROUND OF THE INVENTION
The present invention relates to dental apparatus and more
particularly to a dental chair-instrument tray combination, wherein
the tray automatically follows the chair backrest as the backrest
is moved between an upright and a reclined position.
Various dental chairs are known having an instrument tray or the
like mounted to a support extending from beneath the seat of the
chair. Such an arrangement permits the location of various dental
instruments over the patient within easy reach of the dentist or
his assistant. The support for the tray is usually capable of
movement in both horizontal and vertical planes, so that the tray
can be moved to a position most convenient to the dentist or
assistant.
A primary disadvantage of the prior art trays is that once the tray
is positioned for one patient and one particular dental procedure
repositioning the patient, for example by raising or lowering the
chair or moving the backrest between an upright and reclined
position requires that the tray be manually repositioned. For
example if the backrest is moved between an upright and reclined
position, the dentist or assistant must translate the tray
horizontally so that it follows generally the head of the patient.
Likewise, if the chair is tilted, or if the elevation of the chair
is changed, the tray must be manually repositioned.
In the present invention, the tray is mounted for movement with the
backrest in a manner which maintains the tray level as the chair is
raised, lowered, or tilted or the backrest moved between an upright
and reclined position. As the tray automatically follows movement
of the backrest only minimal manual adjustment, if any, is required
to properly position the tray.
SUMMARY OF THE INVENTION
The present invention may be characterized in one aspect thereof by
the provision of a dental chair having a movable backrest; a
parallel motion linkage having one end supported by the seat of the
dental chair and a second end operatively connected to the backrest
for movement with the backrest; a cantilevered support arm carried
by the second end of the linkage; a tray member supported on the
outward extending end of the support arm; and means for adjusting
the first end of the linkage for orienting the tray member to
substantially true horizontal independently of the level of the
dental chair.
OBJECT OF THE INVENTION
One object of the present invention, is to provide a dental
chair-tray combination wherein the tray is arranged to follow the
movement of the dental chair backrest.
Another object of the present invention, is to provide a dental
tray attached to the movable backrest of a dental chair together
with means for maintaining the tray substantially horizontally
oriented as the backrest is moved between an upright and
reclined.
A further object of the present invention, is to provide a dental
tray mounted to a dental chair in a manner which substantially
eliminates the need for manually repositioning the dental tray as
the chair is moved to various adjusted positions.
A still further object of the present invention, is to provide a
dental tray attached to a dental chair, including means for setting
the tray at a true level position regardless of the floor level on
which the chair is placed.
These and other object and advantages and characterizing features
of the present invention will become more apparent upon
consideration of the following detailed description thereof when
taken in connection with the accompaning drawings depicting the
same.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view partly broken away and in section
showing the dental chairtray combination of the present invention
with the chair backrest in a reclined position; and
FIG. 2 is a cross sectional view on a larger scale of a portion of
the chair backrest taken along lines 2--2 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, FIG. 1 shows the dental chair to include
a conventional lift column 10 for supporting the chair above a
floor surface. The upper end of the lift column carries a seat
frame member 12 which may be fixed to the column as shown or which
may be pivotted to the column to provide for tilting of the dental
chair seat indicated at 14. The dental chair also includes a
back-rest member 16 which is arranged for movement between an
upright and reclined position with respect to the seat. In the
embodiment as shown in FIG. 1, this movement is provided by
pivoting the chair backrest at 18 to an upstanding member 20 of
seat frame 12. This pivoting arrangement is not part of the present
invention and is merely shown to illustrate one way of arranging
the backrest for movement with respect to the seat.
Carried at the rear end of seat frame 12 is a leveling mechanism
generally indicated at 22 to be described in further detail herein
below. Upstanding from the leveling mechanism is a mounting knuckle
24. Mounting knuckle 24 forms one end of a parallelogram linkage,
the other end of the linkage being formed by a support knuckle 26
wherein the mounting knuckle and support knuckle are connected by
parallelogram linkage members 28. The operation of such a
parallelgram linkage is well known in the art and it should be
sufficient for purposes of the present invention merely to say that
the linkage acts to maintain orientation of support knuckle 26
substantially parallel to mounting knuckle 24 as the support
knuckle is moved vertically with respect to the mounting
knuckle.
Support knuckle 26 is mounted in a recess 30 (best seen in FIG. 2)
at one side of backrest 16. A pivot mount 32 is carried by the
support knuckle and extends outwardly from the recess. Connected to
this pivot mount for movement about the mount in a generally
horizontal plane is a cantilevered support arm 34. The outwardly
extending end of arm 34 is pivotted to an arm knuckle 36 (FIG. 1)
which in turn supports one end of a parallel motion linkage arm 38.
Arm knuckle 36 is arranged so that parallel motion linkage arm 38
may rotate in a horizontal plane whereas the linkage itself is
desposed for movement in a vertical plane. The other end of
parallel motion linkage arm 38 pivotally supports a dental
instrument tray 40. It should be appreciated that support arm 34
may be omitted and the parallel motion linkage arm 38 with arm
knuckle 36 connected directly to pivot 32. However, the addition of
support arm 34 is desirable in that it increases the range of
movement of the tray.
Accordingly, with the arrangement shown, tray 40 can be raised or
lowered on parallel motion linkage arm 38 and can be pivoted about
the axis connecting the tray to arm 38, about pivot 36 or about
pivot 32. In addition arm 38 may be spring loaded or provided with
a detent mechanism, both arrangements being well known in the art
for maintaining the tray in any vertically adjusted position.
The means for making the tray follow the movement of the backrest
is best illustrated in FIG. 2. In this respect the chair backrest
is provided with a guide member 42 which forms a portion of recess
30. The guide member is provided with an elongated slot 44 which
extends generally parallel to parallelogram link members 28.
Support knuckle 26 is in turn provided with a guide pin 46 which
extends into guide slot 44. Thus this guide pin keys the support
knuckle to the chair backrest so that the knuckle automatically
follows movement of the chair backrest as it moves between an
upright and a reclined position. The pin is also free to translate
in slot 44. For example, as the chair backrest is lowered, the
guide pin translate in the slot upwards toward the head end. In
this manner the instrument tray is automatically adjusted as the
chair backrest is lowered. When the chair backrest is raised, the
guide pin translates toward the seat and the instrument tray
automatically follows. The parallelogram link members 28 being
anchored at one end to mounting knuckle 24 insures that the pivot
32 on support knuckle 26 is kept horizontally oriented as the chair
backrest is raised or lowered. This in turn, maintains the
horizontal orientation of instrument tray 40.
Since the floor of the dental operatory may not necessarily be
level, the present invention allows for a level adjustment of the
tray independent of the chair. With this arrangement the chair may
be located in the dental operatory and then the tray support
adjusted to a true horizontal position. Adjustment is accomplished
by the tray leveling mechanism generally indicated at 22. This
mechanism includes a spherical socket 48 either attached to or
formed integral with seat frame 12. A ball member 50 rides in the
socket and has an upstanding portion 52 which extends through the
socket and connects to mounting knuckle 24. Any suitable means such
as a locking nut 54 threaded to a flange 56 of the socket holds the
ball firmly in position.
In operation, then, once the chair is located in the dental
operatory, locking nut 54 is losened to permit a tilting of the
mounting knuckle 24 by rotating the ball in spherical seat 48. This
movement of the mounting knuckle is in turn translated through
parallel link members 28 to support knuckle 26 which moves to tilt
arm 34. In this manner the tray can be adjusted to true horizontal
after which the locking nut is tightened to hold the ball firmly in
socket 48.
Thus, it should be appreciated that the present invention
accomplishes its intended objects in providing a dental chair tray
combination having means to automatically cause the dental tray to
follow the movement of the dental chair backrest and which
maintains the tray horizontally oriented during such movement. This
represents a considerable savings in time and energy to the dentist
because the need for manual tray adjustment is minimized and in
many cases eliminated. Since the guide pin 46 is keyed to slot 44,
the mechanism which holds or locks the chair backrest at any
adjusted angle, also holds the instrument tray at a particular
level. Accordingly no separate lock mechanism is required for
holding parallel link members 28 in a vertically adjusted position
corresponding to the inclination to the backrest. Further, the tray
leveling mechanism 22 provides means for orienting tray 40 to a
true horizontal position independent of the level of the operatory
floor and therefore the position of the dental chair. Since dental
trays are customarily are very shallow, permitting the orientation
of the tray to a true horizontal position eliminates the danger of
any implement placed on the tray rolling or sliding off the tray
and on to the floor.
* * * * *