Examination chair with lifting and tilting mechanism

A lift and tilt chair including both motorized lift capability and motorized tilting capability. A hydraulic lift cylinder is provided and operates in conjunction with a motorized tilting system. A seat support is provided having rollers affixed thereto for providing the tilting motion and having the lift cylinder attached thereto for allowing raising and lowering of a patient seated within the chair.

FIELD OF THE INVENTION 
The present invention generally relates to medical chairs and, more 
specifically, to chairs that may be moved by a medical professional to 
place a patient in a desired position. 
BACKGROUND OF THE INVENTION 
Many different types of chairs have been developed in the medical field for 
placing patients in a desired position for treatment or diagnosis. These 
include dental chairs and ophthalmological chairs. One such chair is 
disclosed in U.S. Pat. No. 5,467,002, assigned to the assignee of the 
present invention, the disclosure of which is hereby fully incorporated by 
reference herein. The chair disclosed in this patent has the ability to 
raise and lower a patient seated within the chair and also the ability to 
recline the patient and raise the patient's feet by way of a pivoting 
backrest, leg rest and footrest. Often, it is desirable to simply tilt the 
patient back while leaving the patient in essentially the same seated 
position. Such chairs are typically referred to as "tilt chairs". Various 
tilt chairs have been proposed in the past, however, no chair to date has 
adequately and efficiently allowed a medical professional to both tilt a 
patient into position and raise or lower the patient during or after 
diagnosis or treatment. 
For these and other reasons, it would be desirable to provide a tilt chair 
which is cost efficient in design, yet may be used by a medical 
professional to both tilt a patient automatically into position and raise 
or lower that patient into the ultimately desired position. 
SUMMARY OF THE INVENTION 
To these ends, the present invention provides a medical chair having a 
patient support generally affixed to a base by a lifting and tilting 
mechanism. The lifting and tilting mechanism generally comprises a seat 
support having four rollers mounted thereon and contained within slots 
respectively contained in a pair of support rails affixed to the back of 
the patient support. A pair of rollers is mounted to the front of the seat 
support and a pair is mounted to the rear thereof. The slots are curved to 
define the tilting path of the chair. The lifting and tilting mechanism 
further includes a lifting cylinder rigidly affixed to the seat support 
between the front and rear pairs of rollers. This lifting cylinder is 
connected to a motorized hydraulic pump contained in the base of the 
chair. An actuator is affixed between the patient support and the seat 
support for moving the patient support relative to the seat support by 
movement of the rails along the front and rear pairs of rollers. 
Significantly, the front and rear pairs of rollers are mounted to the seat 
support in generally the same horizontal plane for stability, ease of 
manufacture and proper movement of the rollers within the guide slots. 
It will be appreciated that the invention provides a chair that may have a 
single foot control for use by a medical professional to provide powered 
movement both in a tilting manner and a vertical direction to adjust the 
position of a patient undergoing diagnosis or treatment. The invention 
further provides such advantage in a cost efficient manner due to the 
integrated design of the lifting and tilting mechanism. Additional 
advantages and objects of the invention will become more readily apparent 
to those of ordinary skill upon review of the following detailed 
description of the preferred embodiment taken in conjunction with the 
accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 illustrates a chair 10 constructed in accordance with a preferred 
embodiment of this invention. Chair 10 generally comprises a patient 
support 12 affixed to a base 14 for both tilting and raising or lowering 
with respect thereto as will be described. Patient support 12 comprises 
cushions 16, 18, 20, 22 that are respectively attached to flat support 
members 24, 26, 28, 30. 
As shown in FIGS. 1 and 2, a lifting and tilting mechanism 40 generally 
connects patient support 12 to base 14. Specifically, a lift cylinder 42 
extends from base 14 and is operatively connected to a motorized hydraulic 
pump 44 as generally described in the above incorporated U.S. Pat. No. 
5,467,002. Generally, such hydraulic cylinders are known in the art and 
take many forms. A suitable hydraulic lift mechanism is fully described in 
U.S. Pat. No. 5,461,965, assigned to the assignee of the present invention 
and hereby fully and expressly incorporated by reference herein. Cylinder 
42 is attached to a seat support 46 by a nut 47. As shown in FIGS. 1-3, 
front and rear pairs of rollers 48a, 48b are affixed for rotation relative 
to seat support 46. As specifically shown in FIGS. 1 and 2, front and rear 
pairs of rollers 48a, 48b have two common axes that are each contained in 
generally the same horizontal plane. Rollers 48a, 48b are also connected 
for rolling movement along rails 50, 52. Specifically, rollers 48a, 48b 
are contained within respective curved slots 54, 56 of rails 50, 52. Slots 
54, 56 are closed end slots and the ends thereof may define the limits of 
movement, respectively, of front and rear rollers 48a, 48b. 
As also shown in FIGS. 1 and 2, connector blocks 58 connect rails 50, 52 to 
respective seat support members 26, 28, 30. Side supports 60 (only one 
shown in FIGS. 1 and 2) are also rigidly affixed to rails 50, 52 and 
connect a footrest 62 pivotally at the lower end thereof. A cover 64, 
shown in phantom in FIGS. 1 and 2, may be used to conceal the various 
mechanical hardware of chair 10 at the rear. 
Now referring to FIG. 4, the actuating mechanism for tilting the patient 
support 12 with respect to base 14 includes a threaded rod or drive screw 
66 and a drive nut 72 attached via a pivot 68 mounted generally at the 
rear side of support member 30 and a motor 70 which may rotatably operate 
a worm drive (not shown) that is in meshed relation to threaded rod 66 in 
a conventional manner. Operation of motor 70 by conventional controls will 
cause rotation of the worm drive and rotation of threaded rod 66 within 
drive nut 72. A reversible motor is used to allow rotation of threaded rod 
66 in either direction. It will be appreciated that rotation of threaded 
rod 66 will cause drive nut 72 and therefore patent support 12 to travel 
up and down threaded rod 66 as rails 50, 52 move along the respective 
front and rear rollers 48a, 48b following curved slots 54, 56. 
It will further be appreciated that conventional controls may be used 
operate motorized pump 44 and reversible motor 70 and that a foot switch 
box (not shown) may be provided with multiple switches for depression by 
the operator to respectively raise and lower the chair by operating 
motorized pump 44 and tilt patient support 12 by operation of motor 70. 
The limits of travel for both the lifting and tilting operations may be 
controlled in conventional fashion. One preferred manner of controlling 
the tilting travel is to use a nut 72 that will continue to allow threaded 
rod 66 to rotate at the end of the travel. A timer may then be used in the 
control system to stop motor 70. 
While a preferred embodiment has been described, Applicant does not intent 
to be bound by the details associated with that preferred embodiment, but 
only by the scope of any claims ultimately granted in a patent.