US 3554598 A
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A. DUNKIN 3,554,598 LOW SILHOUETTED DENTAL CHAIRDR THE LIKE Filed Oct. 22, 1968 I g w 7 T in l I I (.0 a1;-
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INVENTOR ALBERT DUNKIN ATTORNEY United States Patent 3,554,598 LOW SILI-IOUETTED DENTAL'CHAIR OR THE LIKE Albert Dunkin, South Norwalk, Conm, assignor to Sybron Corporation, Rochester, N .Y., a corporation of New York Filed Oct. 22, 1968, Ser. No. 769,564 Int. Cl. A61g 15/00 US. Cl. 297-330 7 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The present invention relates generally to an elevating and supporting mechanism for dental chairs and the like. More specifically, to a support and elevating mechanism which permits positioningthe chair in close proximity to the floor surface and which pivots the chair upwardly and forwardly through an arcuate path of travel to a position elevated above the floor surface.
The design of dental chairs for the most part has kept abreast of the advancement in the changing techniques of denistry, dental hygiene and dental surgery. In this respect, dental chairs have become quite mobile and can be raised, lowered, tilted, swivelled or moved along the floor surface in order to place the patient in the position most convenient to the dentist with respect to the particular dental procedure being performed.
The apparatus for raising or lowering the dental chair is contained in the chair base which heretofore included a vertical pedestal or plurality of telescoping sections and either a pneumatic or hydraulic means for moving the pedestal or telescoping sections vertically. This construction, however, placed limits on both the high and low points of travel and permitted the changing of one of these limits only by sacrificing the other. For example, increasing the length of the telescoping sections to raise the high limit of travel increases the overall height of the base which, in turn, raises the low limit of travel. Conversely, decreasing the length of the pedestal, reducing or removing any telescoping section to lower the low limit of travel also lowers the high limit of travel. The dental chair of the present invention, however, is provided with a support and elevating means which is able to move the chair to a high limit of travel which is higher than conventional dental chairs and to a low limit of travel which is lower than conventional dental chairs.
This feature is important for several reasons. For example, the dental chair of the present invention permits the dentist to operate on his patient while the dentist is seated regardless of whether the patient is seated upright or is in a reclined position. In this respect, in cases where the dental procedure requires that the patient be seated upright, the chair can be lowered to substantially floor level so as to position the head portion of an average patient at a height convenient to the seated dentist. In cases where the dental procedure requires that the patient be reclined, the chair can be elevated to its full height and the backrest reclined to maintain the head portion Patented Jan. 12, 1971 of an average patient at a height convenient to the seated patient.
Having a dental chair which is capable of moving to a very low elevation without sacrificing the high limit of travel is also important when the dentist is dealing with an aged or otherwise infirm patient. In this respect, such patients who could not mount the conventional chair or who could do so only with great difficulty, are able to seat themselves directly onto the dental chair of the present invention.
As stated hereinabove, certain dental procedures are performed while the patient is in a reclinging position, the backrest portion of the chair being tilted in such cases to recline the patient. However, any tilt of the backrest portion of prior art chairs alters the orientation of the patients head with respect to the fixed instrumentation in the dental operatory such as X-ray units or the dental console containing the dental drills, cuspidor, aspirators or the like. Accordingly, each time the patient is moved between an upright position and a reclining position, the dentist must reorient the relationship between the patient and his equipment by moving either the dental chair or the equipment.
To overcome this drawback of the prior art, the dental chair in the present invention is provided with an elevating and support means to pivot the chair upwardly and forwardly through an arcuate path of travel. Since the backrest in the present invention can be pivoted as in conventional chairs, the summation of the arcuate upward and forward movement of the chair and the arcuate downward and rearward movement of the backrest maintains the head portion of a patient at substantially the same location regardless of whether the chair is elevated and backrest reclined or whether the chair is at a low level with the backrest upright.
SUMMARY OF THE INVENTION The present invention can be characterized in one aspect thereof by the provision of a dental chair mounted on one end of a cantilevered pedestal which has its other end pivotally mounted to a base platform, the chair being raised or lowered by pivoting the cantilevered pedestal about the base platform. The pedestal can be pivoted to a substantially horizontal position, resting full length on the base platform, positioning the dental chair on the base immediately adjacent and in close proximity to the floor surface. The mechanism for pivoting the pedestal from a substantially horizontal position to an upright position is a ram and cam arrangement which first applies a force in a direction substantially normal to the long dimension of the pedestal to pivot the pedestal from its horizontal position to a partially raised position. Upon reaching a partially raised position, the force applied by the ram and cam is directed substantially parallel to the long dimension of the pedestal to pivot the pedestal to its fully raised position.
OBJECTS OF THE INVENTION The primary object of the present invention is to provide a dental chair or the like capable of being lowered to a position resting on or in close proximity to a floor surface.
Another object of the present invention is to provide an elevating and supporting means for dental chairs and the like which can move a dental chair or the like from a first position resting on or in close proximity to a floor surface to a second position elevated above the floor surface.
A further object of the present invention is to provide a dental chair or the like which has a low limit of travel lower than conventional dental chairs and a high limit of travel higher than conventional chairs.
A yet further object of the present invention is to provide an elevating and supporting means for a dental chair or the like which pivots the chair between the high and low limits of travel.
Another object of the present invention is to provide a dental chair which allows the dentist to operate while seated alongside the patient regardless of whether the patient is seated upright or is in a reclined position.
Still another object of the present invention is to provide a dental chair or the like which maintains the head portion of a patient seated in the chair in substantially the same location as the chair is raised and lowered and the backrest respectively reclined or upright.
These and other objects, advantages and characterizing features of the invention will become more apparent upon consideration of the following detailed description thereof taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation perspective view, partly broken away and in section of the low silhouetted dental chair or the like of the present invention in its fully elevated position with the backrest portion in a reclined position;
FIG. 2 is an enlarged cross sectional view taken along lines 22 of FIG. 1;
FIG. 3 is a side elevation view partially broken away of the low silhouetted dental chair of the present invention at its lowest elevation with the backrest portion upright,
the phantom line representing the position of the headrest portion when the chair is in the position shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, FIG. 1 shows the low silhouetted dental chair or the like of the present invention generally indicated at to include a seat and back rest portion 12 and 14, respectively, the backrest being hinged to the seat portion in a conventional manner for purposes of tilting the backrest and reclining a patient seated in the chair. The dental chair also includes an adjustable headrest 13 connected to the backrest, a relatively fiat base 16 and a cantilevered chair support and elevating column 18 pivoted at one end 20 to the seat portion of the chair and its other end 22 to the forward portion 24 of base 16.
The support and elevating column is composed of two nesting channel sections 26 and 28 which together form a housing 30 for the chair elevating mechanism generally t indicated at 50. Each channel section is pivoted to both the seat and chair base, channel section 26 being pivotally connected at 32 and 34 and channel section 28 being pivotally connected at 36 and 38 to the seat and base respectively. As shown in FIGS. 1 and 3, the horizontal spacing between adjacent pivots, for example, pivots 34 and 38 is greater than the vertical spacing between the same pivots. Thus, the disposition of pivots 32, 34 and 36, 38 forms a parallelogram, making channel sections 26 and 28 a parallel motion linkage which acts to maintain the seat in a horizontal position as column 18 is pivoted about its pivoted end 22 to raise or lower the chair.
The chair elevating mechanism housed within the nesting channel sections 26 and 28 for pivoting column 18 about its end 22 includes opposed lift cams 40, 42 and 44 (FIG. 2), a driven member 46 and any suitable drive means such as a hydraulic cylinder 48 (FIG. 1). As shown in FIG. 2, cams 42 and 44 represent a cam pair which is fixed to channel section 28. Cam 40 is fixed to channel section 26 and opposed to cam pair 42 and 44 and is positioned to fit between the cam pair so that member 46 when driven between the cams will tend to drive the opposed cam 40 and cam pair 42, 44 apart.
FIGS. 1 and 2 show that cams 42 and 44 have an inclined cam surface 52 thereon that extends substantially the entire length of the cam. Cam 40, however, has an arcuate cam surface 54 which at one end 56 terminates in a stop 58 (FIG. 1) for purposes set out herein below.
Cylinder 48 for driving member 46 between the opposed cam and cam pair is pivotally mounted to channel section 28 at 60 and can be activated by any suitable means (not shown) to pivot cantilevered column 18 to the position shown in FIG. 1.
OPERATION The operation of the invention will be described for purposes of illustration as beginning with the chair position at its lowest elevation as shown'in FIG. 3. In this position column 18 lies in substantially horizontal position and rests full length on base 16. The chair in turn rests substantially full length on column 18 which supports the chair in close proximity to the floor surface. As shown in FIG. 3, the chair is positioned so close to the floor surface that for all practical purposes the chair can be said to rest on the floor.
To elevate the dental chair, cylinder 48 is energized to drive member 46 between opposed cam 40 and cam pair 42, 44. As shown in FIG. 3, driving member 46 between the cams exerts a vertical force on the cams which is substantially normal to the horizontally disposed channel sections 26 and 28. This force tending to separate the channel sections vertically causes column 18 to pivot about base 16. As member 46 continues to move between cam 40 and cam pair 42, 44, the opposed cams are moved farther apart until cantilevered column 18 is pivoted to an inclined position.
As the travel of member 46 reaches end 56 of cam 40, the member has forced the cams apart to such an extent that member 46 can no longer exert a force normal to the cam surfaces. Member 46 now engages stop 58 on the end of cam 40. Since one end of hydraulic cylinder 48 is pivoted at 60 to channel section 28, the engagement between driven member 46 and stop 58 exerts an axial force between channel sections 26 and 28 which tends to move the sections axially one relative to another. This relative axial movement causes column 18 to pivot still farther until the full elevated position of column 18 is reached as shown in FIG. 1. Thus, cylinder 48 and member 46 in pivoting column 18 from its lowest substantially horizontal position to its highest substantially upright position first directs a force generally normal to the channel members to pivot column 18 to a slightly elevated position and then applies force substantially axial to the channel sections to pivot column 18 to its full elevated position. To lower the column, hydraulic fluid is merely bled from cylinder 48 to permit gravity to lower the chair to any desired partially elevated position.
It should be appreciated that as the chair is being elevated, the pivoting action of column 18 causes the chair to move upwardly and forwardly through an arcuate path of travel. Backrest portion 14 when tilted, moves downwardly and rearwardly through an arcuate path of travel. While not necessarily an essential, it is highly desriable that during such movements the orientation of the patients head portion with respect to fixed instrumentation, remain substantially constant. Accordingly, in another embodiment of the invention the length of column 18 is substantially equal to the length of backrest 14. If column 18 and backrest 14 are substantially equal in length, elevating the chair by pivoting column 18 and therefore the chair upwardly and forwardly and then pivoting the backrest downwardly and rearwardly to a reclined position produces the net result of maintaining headrest 13 at substantially the same orientation. The relative positions of headrest 13 when the chair is elevated and the backrest reclined or when the chair is at its lowest position and the backrest upright are shown in phantom line and solid line respectively in FIG 3. The phantom and solid line shown in FIG. 3 clearly illustrates that the summation of the upward and forward movement of the chair and the rearward and downward movement of the backrest 14 maintains headrest 13 in substantially the same position with respect to any fixed instrumentation (not shown) such as X-ray units or dental consoles present in the dentist ofiice. This permits the dentist to move the patient between a variety of elevated and reclined positions with out materially altering the orientation of the patients head portion with respect to the instrumentation.
Thus, it should be appreciated that the present in- 'vention accomplishes its intended objects, providing a dental chair which greatly increases the convenience and efficiency of the dentist. The ability of the chair elevating and support mechanism to lower the chair, for all practical purposes, to floor level allows the dentist to perform substantially all dental procedures while seated. The feature of pivoting the chair through an arcuate path of travel to an elevated position permits the dentist to vary the patients position without substantially changing the orientation of the pat-ients head portion with respect to the fixed dental instrumentation. Moreover, providing a chair which can be lowered to a position in close proximity to the floor surface permits a patient to seat himself directly on the chair and eliminates the need for mounting the chair. This is of great convenience to some patients such as the aged or infirm who are unable to mount the conventional dental chairs without assistance.
While cam follower 46 is shown in the figures as a single unit, the invention also contemplates the use of a three part cam follower journaled to the end of the drive means so that each part applies a force to one of the cams. Such construction allows the cam followers to rotate as they are driven between the cams and the cam followers.
While a preferred embodiment of the invention has been described, it should be apparent that various modifications can be made therein without changing the spirit and scope of the invention as claimed.
Having thus described the invention in detail, what is claimed as new is:
1. A low silhouetted dental chair or the like comprising:
(a) substantially fiat base adapted to rest on a floor surface;
(b) a parallel motion linkage including a pair of parallel members each having one end pivotally connected to said base and a second end pivotally connected to said chair, said parallel members, in one position being substantially horizontally disposed to locate said chair in close proximity to said floor surface; I
(c) a driven member movable axially between said parallel members; and
(d) means associated with said parallel members for causing said parallel members to pivot about said base to a second substantially upright position as said driven member is driven axially therebetween to locate and support said chair above said floor surface, said means applying a force substantially normal to said horizontally disposed parallel members to pivot said parallel members first to a partially raised position and thereafter to a substantially upright position, said chair being maintained substantially horizontally oriented by said parallel motion linkage as said chair is raised and lowered.
2. A low silhouetted dental chair or the like as in claim 1 wherein:
(a) said driven member is a cam follower; and
(b) said means associated with said parallel members include opposing cam surfaces shaped to direct the force of the axial movement of said cam follower substantially normal to the path of travel thereof causing said members to pivot about said base.
3. A low silhouetted dental chair or the like comprising: (a) a substantially flat base;
(b) a parallel motion linkage including a pair of elongated members, each pivoted at one end to said base and at the other end to the seat portion of said dental chair, said members being adapted to lie one adjacent another substantially fiat on said base so as to support said dental chair substantially at floor level;
(c) a driven member movable through a path of travel between said elongated members; and
(d) opposed cam elements associated with said elongated members, said cams having the opposing cam surfaces thereof engaged by said driven member and shaped so the force of the movement of said driven member is directed normal to the path of travel thereof causing said opposed cam surfaces and the elongated members associated therewith to move apart in opposite directions and to pivot about said base.
4. A low silohuetted dental chair or the like comprising:
(a) a substantially flat base;
(b) a parallel motion linkage including a pair of elongated parallel members, each pivoted at one end to said base and at the other end to the seat portion of said dental chair, said members being adapted to lie one against another substantially flat on said base so as to support said dental chair substantially at floor level;
(c) a driven element movable through a path of travel axially between and substantially parallel to said elongated members, said driven element engaging both of said elongated members throughout said path of travel for moving one of said members relative to another causing said members to pivot about said base and elevate said chair; and
(d) drive means operatively connected to said driven element for moving said element through said path of travel.
5. An apparatus for elevating and supporting dental chairs and the like above a floor surface comprising:
(a) a pair of parallel members each pivotally supported at one end adjacent floor level and each pivotally connected at another end to said chair, said members being movable between (i) a first position wherein said members are substantially horizontally disposed one adjacent to another to locate said dental chair in close proximity to said floor level and (ii) a second position wherein said members are substantially upright and spaced apart to locate andlsupport said chair spaced above said floor eve said two members together providing a parallel motion linkage to maintain said chair substantially horizontally oriented as said members move; and
(b) drive means applying first a force normal to said members for moving said members apart to pivot the same to a partially raised position and thereafter applying a force axially to said members for moving one of said members axially with respect to another to pivot said members to said substantially upright position said drive means including (i) a driven element movable axially between said parallel members and (ii) a cam associated with said parallel members and cooperating with said driven element for causing said members to pivot about said base as said element is driven axially with respect to said members.
6. Apparatus as set forth in claim 5 wherein said drive means includes opposed cams, one of said cams being associated with each of said elongated members, said driven element being movable between said opposed cams to force the same apart and pivot said members to said partly raised position.
7. Apparatus as set forth in claim 5 wherein said drive means comprises a stop associated with one of said members and lying in the path of travel of said driven References Cited UNITED STATES PATENTS Gaflney 297330 Dome 248421 Lory 297--347X Nichols 248-419 Persson 297345 Robinson 297330X FRANCIS K. ZUGEL, Primary Examiner Gould 248421X Davis et a1 248-419 10 Dalryrnple 248421X 297 347248 421 Davis 297-345 U .S. C1. X.R.