US3059970A - Chairs having tilting backs - Google Patents

Description

Oct. 23, 1962 R. c. ANGELL ET AL 3,059,970

CHAIRS HAVING TILTING BACKS Fild Feb. 1, 1960 4 sheets-sheet .1

RC BERT C. RNC-IEM., deceased BY JAMES Aussu- Execuron wlw/nm UHLER ATTo QNEYS Oct. 23, 1962 R. c. ANGELI. ET AL 3,059,970

CHAIRS HAVING TILTING BAcKs Filed Feb. l. 1960 4 Sheets-Sheet 2 @05am-r C. ANCTELL, dzczaszc BYJAmes BANGELL EXECUTOR 6- WILMER P. UHLER BY 9211441", @mic/)s w ATTO 2 N EYS Oct. 23, 1962 R. c. ANGELI. ET AL 3,059,970

CHAIRS HAVING TILTING BAcKs Filed Feb. l. 1960 4 Sheets-Sheet 5 JAMES aANGaLL ExEcu'roR BY ,wlLMER RUHLER ATTORNEYS Oct. 23, 1962 R. c. ANGELL ET AL 3,059,970

CHAIRS HAVING TILTING BAcKs Filed Feb. l. 1960 4 Sheets-Sheet 4 BY JAMES B.ANGE| L,ExEcu'roR 8-WILMER r. UHLER United States Patent liice 3,59l@ Patented Giet. Z3, 1962 gaat 3,059,970 CHAIRS HAVlNG TllZTlNG BACK@ Robert C. Angell, deceased, late of Staten island, NPY., by lames B. Angell, executor, Menlo Parli, Salif., and Wilmer l. Uhler, Tottenville, NX., assignors to The S. S. White Dental Manufacturing Company, Philadelphia, Pa., a corporatian of Pennsylvania Filed Feb. l, 1964i, Ser. No. 5,941 14 Claims. (Cl. 297-353) This invention relates to adjustable back structures for chairs, such as those employed by dentists for seating patients, and is particularly concerned with means for positioning and holding supports for the back and head of the occupant.

It is known to have chairs with sliding back rests and head rests, and the instant matter concerns improvements in supporting, guiding and position-locking structures.

An object of the invention is the provision of a chair structure having a back frame, a slidable back rest, a slidable head rest, and a single guide means for said rests.

Another object is the provision of a chair structure having a back frame, a slidable back rest, frame-carried guiding means for the back rest, and means for compensating at least a part of the weight of the back rest.

Another object is the provision of a chair structure having a back frame, a slidable head rest, frame-carried guiding means for the head rest, and means for compensating a part of the weight of the head rest.

Another object is the provision of a chair structure having a back frame, a slidable back rest, frame-carried guiding means for the back rest, and position-locking means for xing the back rest and including a self-adjusting part cooperative with locking devices acting against opposed surfaces of said part.

Another object is the provision of a chair structure having a back frame, a slidable back rest, frame-carried guiding means for the back rest, position-locking means for fixing the back rest and including a transversely movable part on the frame and oppositely acting locking devices on the back rest cooperative with said part, and manual control means on the back rest for actuating said locking devices.

Another object is the provision of a chair structure having a back frame, a slidable back rest, a slidable head rest, frame-carried guiding devices for the head rest, position-locking means for fixing the head rest and including a transversely movable part on the back rest and oppositely acting locking devices on the head rest cooperative with said part, and manual control means on the head rest for actuating said locking devices.

Another object is the provision of a chair structure having a hollow back frame, a closure for the back frame, a slidable head rest, frame-carried guiding means for said rests concealed by said closure, concealed position-locking means for the back rest and effective to prevent upward and downward movements of the back rest, position-locking means for the head rest concealed by said closure and effective to prevent downward movement of said head rest while permitting free upward movement thereof, accessible manual control means on the back rest to actuate the position-locking means for the back rest, and accessible manual control means on the head rest to actuate the position-locking means for the head rest.

With these and other objects in View, as will appear in the course of the following description and claims, an illustrative embodiment of the invention is shown on the following drawings, in which:

FIG. l is a side elevation of a chair including the instant invention;

FIG. 2 is a rear elevation of the same;

FIG. 3 is a View, on a larger scale, of the rear of the back frame with parts thereon;

FIG. 4 is an upright section, substantially on line 4-4 of FIG. 3;

FlG. 5 is a fragmentary section, substantially on line 5--5 of FIG. 4;

FIG. 6 is a like section, substantially on line 6--6 of FlG. 4;

FIG. 7 is a horizontal section, substantially on line 7-7 of FIG. 3;

FIG. 8 is an explosion view of head rest parts;

PEG. 9 is a horizontal section of certain parts, substantially on line 9 9 of FIG. 4, at a larger scale.

In these drawings, the illustrated chair is for dentists use; and has a base lll for mounting on a iloor, with a telescoping column il rising therefrom and having at the top a seat structure i3 with a foot rest l5. A tilting back 16 is pivoted relative to the seat structure for adjustment to and locking in various positions by devices not further shown but indicated as including a manual control 17 on the back. The chair is illustrated as having arm rests l8r.

The back i6 of FIGS. l and 2 has a rigid hollow frame Ztl, FIGS. 3 and 4, on which the parts according to the invention are mounted. A back cushion 21 is connected by pivots having clamping devices to a sliding member 22 having transverse projections 23, 24 at its upper and lower ends, these projections having apertures for sliding engagement with the upright guide rods 25 which are fixed at their upper and lower ends in the frame 20 and are located between the sliding member 22 and the side walls 26 of the frame 2G. Upright rods 27, parallel to rods 25, likewise extend loosely through apertures of the projections 24 and are secured to the frame Ztl at their upper and lower ends. Compensating coil springs 28 surround the rods 27 and bear against the frame 20 and the end surfaces of pockets formed in the projections 23: these pockets being formed as enlargements around the rods 27 and extending for a part of the vertical dimension of the projections 23 so that the pockets are annular with their end walls providing abutments for the ends of the corresponding springs. In construction, the blocks 30 may be formed to receive the rods 25, 27 and the springs 28, and ixedly secured to the lower end of the base frame member: like blocks 31 may be secured to the base frame at its upper end.

A second sliding member 35 is guided by the rods 25 between the projections 2.3, 24; and has an upward eX- tension 36 which projects above the back lframe 20 and has a pivot mounting 3-7 at its upper end for the head rest 37a. A rod 38 extends downward from the member 35 at a point not in vertical alignment with the sliding member 20, and is connected to a tension coil spring 39 whose other end is connected to an ear 46 on a projection 23.

Rubber cushion rings 42 may be provided around the rods 25 at the ends thereof, and between the several sliding structures, to cushion the parts at the ends of travel, and to avoid noise. It is preferred to provide cushion sleeves 43, eg, of nylon, around the rods 27 to prevent noise as the spring turns move therealong.

A position-locking means for the sliding member 22 which carries the back cushion 21 includes an upright rail 45 which extends along notches 46 in the sliding members, and is held by screws 47 at the top and bottom of the frame structure whereby upward and downward movement of the rail 45 is prevented. These screws pass through transverse slots 4S of the rail; and are not tightly engaged therewith, so that lateral or transverse movement of the rail is permitted at either or both ends. A rear cover member 49 is formed integral with a rearward projection 50. Two horizontally spaced blocks 49a are positioned in abutment with the member 22 and the cover member 49 (FIG. 9), and the assembly is maintained by screws 49]) which pass through the likewise spaced front blocks 22a, and the parts 22, 49a and are threaded into the -member 49. The projection 5@ is hollow, and provides a handle for raising the member 22 and the cushion 2l. A manual control button 5l projects through its upper surface; so the position of the cushion can be adjusted by a single hand, with the fingers beneath the projection 50 and the thumb upon the button 5l. The button 51 is pivotally mounted on a lever 52 which extends forward between the blocks 49a and has a press-fitted pin 53 which is supported in holes in the front blocks 22a, with a stop screw 53a to limit upward movement of the lever. An upright thrust rod 5d has its upper end engaged beneath the lever 52 to be forced downward thereby: the rod 54 is guided in a projection 55 on the member 22, FIG. 4, and is threaded near its lower end to receive an adjustable nut sleeve 56, while a reduced lower end is guided in a pocket in a vertically slidable locking block 57, FIGS. 4, 5 and 6, which is guided by the rods 5S engaged, FIG. 5, at their upper ends in ears of the sliding member 22 and at their lower ends in the plate 59 secured to the lower end of the member 22. Compression `springs 60 around these rods act to lift the block 57. The block 57 tits loosely around the rail 45, and has apertured extending wings 6]. at the opposite sides of the rail 45. Laterally outside the wings 6l, the member 22 has upwardly convergent surfaces 62 which may be provided upon replaceable wear pieces attached to the member 22. Rollers 63 are provided in the wing apertures, so that they can travel along the sides of the rail and, upon upward movement relative to the member 22, can wedge between the surfaces 62 and the rail 45 and lock the parts against downward movement of the member 22 and its back cushion 2l along the back frame. The block 57 is cut away adjacent the rail 45 illustratively below the wings 61 to provide downwardly convergent surfaces 64. Rollers 65 are located between the surfaces 6d and the sides of the rail 45 so that wedging effects are established when the block 57 is raised relative to the sliding member 22. A 'Ugshaped retainer 66, which extends around the sides of the rail 45, is apertured for the balls 65; and is provided with threaded extensions 67, passing through the plate 59, which may be adjusted by nuts 68 to assure that balls 63, 65 are wedgingly engaged upon the upward movement of the block 57.

The upward extension 36 of the second sliding member 35, which carries the head rest, has an upright slot between its side walls, for receiving a second upright rail 70 which is secured by screws 71 to the rst sliding member 22 against relative upward and downward movement, but with permissive lateral movements as with the rail 45. The rear face of the extension 36 is in part closed by cover plates 72 secured thereto; these plates 72 having flanges 73 which extend into the slot in the extension 36 and provide guides for the vertical movement of a lockcontrolling slide member 74. Near the upper end of extension 36 is a projection 75 which may be engaged by the fingers of one hand for lifting the second sliding member 35 and the head rest thereon. A thumb button 76 extends through an opening in the top of the projection 75, and is pivotally connected to a lever 77 which is pivoted at 78 within the extension. The lever 77 rests on the head of a pin 79 which is threaded in a horizontal flange 80 at the top of the slide member 74. A compression spring 81 is located around the stem of the pin 79 and interposed between the ange 80 and a cross piece 82 of the extension 36 for urging the slide member 74 and the lever 77 upward. A stop screw S3 can be provided in the projection 75 to limit the upward movement of the lever 77.

The sliding member 74 has an opening along its height for the guiding engagement with flanges 73; and has a U-shaped locking block 85 secured at its lower end, this block 85 extending around the sides of the second rail 70,

with locking rollers 86 carried in apertures of its wing walls. Wedge blocks 87 are xed in internal notches of the sliding member 35 at the lower end of its vertical slot, and provide upwardly convergent surfaces 8S on the member 35 and located in spaced relation from the sides of the second rail 70, so that the rollers S6 can become wedged between the rail and the surfaces 88 upon downward movement of the member 35 relative to the rail or upon upward movement of the block under the action of spring 8l relative to the member 35.

The hollow of the extension 36 is closed at the upper ront by a closing plate 90 ixed thereto, and having anges 91 extending along the sides of the extension. A lower telescoping plate 92 has its lower edge xed to the upper part of the back frame 2t) for covering the lower part of the extension hollow when the head rest is fully raised; and an intermediate plate 93 telescopes with respect to the plate 92 when the head rest is lowered, and has a top ange 94 for engagement by the sliding member during relative movements, and bottom portions 95 for engagement with ears 96 on the plate 92 to prevent excessive extension.

The illustrative embodiment shows the compactness and external smoothness which can be attained. The front of the head rest slide 35, 36 at any part above the back frame 2@ comprises the telescoping plate assembly 90, 92, 93, so that the operating parts are protected and concealed thereby at the rear. The rear of the head rest slide 35, 36 has the plates 72 for alike purpose, but with a recess between the anges 73 so that this slide 35, 36 can telescope into the back frame without interference by the rear plate 49 thereof and so that the projection 50 and button 51 can be mounted close to the top of the frame 20 for easy and convenient access. The guide and spring rods are covered by the rear side plates 95, FIG. 2, so that the sliding member 22 and its parts can move between them. Therewith the guides, counterbalance springs, lock members and rails, and the lock actuators are concealed, and are protected from contact.

`.When it is desired to adjust the position of the back cushion 2li, e.g. from the full Iline to the dotted line position of FIG. l, the dentist can place the iingers of one hand beneath the projections 50, with the corresponding thumb on the button. Upon pressing the button and lifting the projection, the sliding member 22 moves upward with the cushion 2l thereon, the movement being assisted by the action of the counterbalance springs 28'. The releasing action is attained from the downward rocking of .the lever 52 and the downward movement of the rod 54 so that the locking member 57 is pressed downward against its springs 6l). Therewith the rollers 63 are drawn downward by the wings 6i of the members 57 and no longer wedge between the convergent surfaces 62 and the surfaces of the rail 45; and also the member 57 moves relative to the plate 59 and the retainer 66, so that the rollers 65 are freed of wedging engagement between the convergent surfaces 62 and the surfaces of the rail 45. The sliding member 22 is then free to move up or down: illustratively it is being lifted by the projection 56, and it will be seen that the pinching engagement of the projection and the button 51 is a natural one and that the travel of the member 22 does not require any change of this pinching engagement. When the back is to be moved downward, the depression of the button 511 releases the member, and continued pressure on the button 51 forces the member 22 downward against the action `of its springs 28. Upon releasing the button 51, the springs 60 lift the locking member 57 into position so that its rollers 63, 65 reestablish wedging engagement between the respective surfaces 62, 64 and the sides of the rail 45. The springs 60 also then act through the rod 54 to lift the button 51. The permitted transverse movement of the rail, with the guided movement of the wedging surfaces 62, 65 permits automatic compensation between dierential forces being exerted at the rollers 63,

65 at one side: the rail 45 then yields to the greater force until the forces balance. Thus, no careful adjustment is necessary, and diterential wear is accommodated.

A like operation is performed when .the head rest 37a is to be adjusted vertically with respect to the back-frame and back cushion. In this case, the button 76 is depressed `and the head rest structure including the sliding member 35 is moved up or down. Therewith, the sliding lock 7d is depressed, and the blocl; 35 moves the rollers 86 out of wedging engagement between the convergent surfaces 88 and the sides of rail 70; and upon release of the button 76, the spring ttl lifts the Elock members 74, 85 so that wedging is re-established. Also, the head rest may be raised without operating the button 76, by merely lifting the sliding parts including the members 35', 36, wherewith the rollers 86 act as in an over-running clutch. The parts likewise permit automatic compensation of differential forces atV the rollers 86, in the manner described for the sliding member 22, and its locking system.

The illustrative practice is not restrictive; and the invention may be practiced in many ways within lthe scope of the appended claims.

We claim:

l. A chair assembly having `a seat and `a back, said back including a frame having vertical guides, a sliding member movable along said guides, a back `support on said sliding member, a rail held to the frame against relative vertical movement, said sliding member having a lirst surface thereon convergent upwardly toward the rail, a locking member movable along Ithe rail relative to the sliding member and means urging the same upward, said locking member having a second surface thereon convergent downwardly toward the rail, a tirst wedging device carried by the locking member for engagement between said irst surface and the rail, a second wedging member carried by the rsliding member for engagement between said second surface and the rail, and manually operable means for pressing said locking member downward relative to the sliding member.

2. A `chair assembly having a seat and a back, said back including a frame having vertical guides, a sliding member movable along said guides, a back support on said sliding member, a rail held to the yframe against relative vertical movement and having permissive lateral movement, said slider having upwardly convergent rst surfaces located with the rail between them, a locking member movable along the rail relative to the sliding member and means for urging the same upward, said locking member having downwardly convergent second surfaces located with the rail between them, rst locking elements carried by the locking member in the spaces between said rst surfaces and the rail, 4second locking elements carried by the sliding member in the spaces between said second surfaces and the rail, and manually operable means for moving said locking member downward.

3. A chair assembly having a seat and a back, said back including a frame having laterally spaced vertical guides, a sliding member movable along said guides, a rail held by said frame against relative vertical movement and having permissive lateral movement, locking elements effective to hold said sliding member against relative downward and upward movement along the rail and positioned to act against opposite faces of the rail, a locking member movable vertically relative to said frame and said sliding member and cooperative with said locking elements, spring means to urge `said locking member in one vertical direction for engaging the locking elements, a manually accessible element carried by and movable relative to said sliding member, and a connection from said manually accessible element to said locking member for moving the latter against the action of the spring means lfor releasing said locking elements, said llocking member being cooperatively connected with said locking elements to lcause said rail to move laterally under differing forces by said locking elements 4thereon until the locking efforts on said rail are balanced.

4. A chair assembly as in claim 3, in which the sliding member has an outward projection for engagement for moving the sliding member upward, and in which the manually accessible element is depressibly mounted at the top of the projection so that ythe thumb of a hand can be employed to depress the manually accessible element for releasing the locking elements and also produce downward movement of the sliding member, and the iingers of a hand can be employed to lift the sliding member when the thumb thereof has depressed the manually accessible element.

5. A chair assembly having a seat, a back and a head rest, said back including a frame having ixedly spaced upper and lower parts and ver-tical guides extending between said parts, a sliding back member movable along said guides between said parts and having vertically spaced portions engaged with the guides, a sliding head rest member movable along said guides between said spaced portions of said sliding back member and having second portions engaged with said guides between said back member portions, a back rest carried by the sliding back member, a head rest carried by said sliding head rest member, means for locking said sliding back member to the frame, manually operable means on the sliding back member for releasing said locking means thereof, means for locking said sliding head rest member to said sliding back member, and manually operable means on the sliding head rest member for releasing said locking means thereof.

6. A chair assembly as in claim 5, in which each sliding member 'has a projection by which it may be raised, and in which the manually operable means thereof includes a depressible piece located at the top of the respective projection.

7. A chair assembly having a seat, a back and a head rest, said back including a yframe having vertical guide rods fixed therein, a rst sliding member having a central portion and upper and lower projections therefrom for .guided engagement with the said guide rods, a second sliding member having a central portion and projections therefrom for guided engagement with said guide rods and located between the upper and lower projections of the iirst sliding member, means for locking the irst and `second sliding members against movement, a back support on the irst member and a head rest on the second member.

8. A chair assembly as in claim 7, including compression spring means around a said guide rod for constantly urging said rst member upwardly along the guide rods and thereby compensating for the weight of the back support, and spring means for urging said second member upwardly relative to said irst member.

9. A chair assembly as in claim 7, in which the locking means includes a first rail secured to the frame against relative vertical movement and having permissive lateral movement, a second rail secured to the first member against .relative vertical movement and having permissive lateral movement, devices carried on the first member for engaging opposite sides of the first rail to lock the iirst member to the rst rail, devices on the second member for engaging opposite sides of the second rail to lock the second member to the first rail, and manually operable means for releasing said devices.

l0. A chair assembly as in claim 9, in which the first member and second member have upwardly convergent surfaces with the respective rail positioned therebetween, locking members movable relative to the sliding members engage and control the said devices, and said manually operable means are eective to move said locking members.

11. A chair assembly having a seat, a back and a head rest, said back having a frame with vertical guides, a irst sliding member movable along said guides, a back support on said rst member, means `for xing said rst member against movement relative to said frame, a second sliding member movable vertically relative to said rst member, a rail secured to the rst member, parts on the second member having upwardly convergent surfaces with the rail between them, a `locking member movable along the rail relative to the rail and the second member, locking elements carried by the locking member for wedging engagement between said rail and said surfaces, the rail lbeing mounted for permissive lateral movement in response to differential pressures by said locking elements, spring means for urging said locking member upwardly, and manually operable means for pressing the locking member downwardly.

12. A chair assembly as in claim 11, in which the `second member has a rearward projection for engagement `for lifting the second member, and in which the manually operable means includes `a ydepressible element located at the top of the projection.

13. A chair assembly having a sea-t, a back and a head rest, said back having a hol-low frame having xedly spaced upper and lower parts, with vertical guides eX- t'ending between said parts, a rst sliding member movable on said guides between said parts, a second sliding member movable on said guides, spring means for urging the rst member upward relative to `the frame, spring means -for urging the second member upward relative t the rst member, a manually operable element near the topof the first member and means controlled thereby for locking the first member to the frame, a manually operable element near the top of the second member and means controlled thereby for locking the second member to the rst member, and cover plates connected with the frame and extending between said parts for enclosing said guides, spring means and locking means.

14. A chair assembly as in claim 13, including a first rail secured to the frame against relative vertical movement and having permissive lateral movement and forming part of the locking means for the rst member, said means for locking said rst member including devices for engaging opposite sides of said rst rail, a second rail secured lto the rst member and forming part of the locking means for the second member, and cover plates for the second member, said cover plates enclosing said rails.

References Cited in the le of this patent UNITED STATES PATENTS 346,784 Stanford Aug. 3, 1886 671,300 Sibley Apr. 2, 1901 1,031,637 Fischer `Tuly 2, 1912 1,814,877 Weber July 14, 1931 2,426,336 Binus Aug. 26, 1947 2,905,274 Cook Sept. 22, 1959 2,985,228 Golden May 23, 1961

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