US3675887A

US3675887A - Chair control assembly

Info

Publication number: US3675887A
Application number: US106440A
Authority: US
Inventors: James R Meinhardt
Original assignee: Seng Co
Current assignee: Seng Co
Priority date: 1971-01-14
Filing date: 1971-01-14
Publication date: 1972-07-11
Anticipated expiration: 1989-07-11

Abstract

A control for a spring biased tilting chair such as an office swivel chair or a platform rocker has a slotted spring ring means which is either a set of aligned slotted spring rings or a single long slotted spring ring or sleeve. A tension adjusting member on the base or head piece has a finger which projects into the slot, and there is a tension member on the tilting member which also has a finger projecting into the slot. The tension adjusting member is operatively connected to an adjusting hand wheel to vary prestress in the ring means, which resiliently resists tilting movement of the tilting member. The structure is equally applicable to an executive chair a secretarial posture chair, an executive posture chair or a platform rocker.

Description

United States Patent Meinhardt Assignee:

Filed:

Appl. No.:

US. Cl ..248/378, 248/382, 248/ 123 Int. Cl. ..Fl6m 11/20 Field of Search ..248/l23, 292, 376, 378, 379, 248/382, 386; 267/131, 132, 133, 158

References Cited UNITED STATES PATENTS Hoffman ..248/382 Scherer ..248/382 X ay We Primary ExaminerWilliam H. Schultz Attorney-Hofgren, Wegner, Allen, Stellman & McCord [57] ABSTRACT A control for a spring biased tilting chair such as an office swivel chair or a platform rocker has a slotted spring ring means which is either a set of aligned slotted spring rings or a single long slotted spring ring or sleeve. A tension adjusting member on the base or head piece has a finger which projects into the slot, and there is a tension member on the tilting member which also has a finger projecting into the slot. The tension adjusting member is operatively connected to an adjusting hand wheel to vary prestress in the ring means, which resiliently resists tilting movement of the tilting member. The structure is equally applicable to an executive chair a secretarial posture chair, an executive posture chair or a platform rocker.

l 1 Claims, 11 Drawing Figures July 11,1972

P'ATE'N'TEDJuL 1 1 m2 SHEET 1 BF 4 J72 21622302 )Jamesz M@n%zz j/f/nw M 554 @25 3 I a l X L a; 1 i v Q A I J II I I iWW 5 fi CHAIR CONTROL ASSEMBLY BACKGROUND OF THE INVENTION Present chair controls utilize various types of resilient devices to provide yieldable pivotal movement of a chair seat and back or chair back alone relative to the chair base. Such devices include relatively large compression spring assemblies, torsion bars, or rubber sleeve members bonded to concentric metal sleeves at the inner and outer cylindrical surfaces of the rubber sleeve. All of these devices require complicated supporting and mounting structures for the chair seat or back and related chair structure and are relatively expensive. There is a need for a simple and inexpensive chair control construction which obviates the problems of prior chair controls.

SUMMARY OF THE INVENTION I The present structure affords a simple and inexpensive chair control which uses slotted spring ring means in the form of a sleeve, or a set of aligned slotted spring rings, instead of any of the resilient means heretofore employed in chair controls to resiliently resist tilting of the seat and back, or of the back alone.

The principal object of the invention, therefore, is to provide a simple and inexpensive chair control for tilting chairs.

Another object of the invention is to provide a tilting chair control which utilizes readily available and easily fabricated split rings or sleeves as a resilient means.

Yet another object is to provide a novel structure which is equally applicable to executive chairs, or to posture chairs of the secretarial or executive type.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a chair control assembly as mounted on an executive type office chair;

FIG. 2 is a front elevational view of the assembly with the tension adjusting knob and bolt omitted;

FIG. 3 is a top plan view of the chair control assembly;

FIG. 4 is a vertical sectional view taken substantially on the line 4-4 of FIG. 3;

FIG. 5 is an exploded perspective view showing a set of slotted spring rings and the tension and tension adjusting members of the assembly;

FIG. 6 is a side elevational view of an embodiment of a chair control for a secretarial posture chair with parts broken away;

FIG. 7 is a plan view of the assembly of FIG. 6 with parts broken away and the back supporting swivel plate omitted;

FIG. 8 is a side elevational view of an embodiment of a chair control for an executive posture chair; 7

FIG. 9 is a top plan view of the assembly of FIG. 8 with the back supporting swivel plate omitted;

FIG. 10 is a vertical sectional view taken substantially on the line 10-10 of FIG. 8; and

FIG. 11 is a perspective view of an alternate slotted spring ring means in the form of a unitary slotted sleeve.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings in detail and referring first to FIGS. 1 to 4, a chair control assembly, indicated generally at is mounted on a spindle 21 of a chair base (not shown). The spindle 21 has a tapered upper end 21a received in a forging 19 which is riveted to the bottom wall 22 of a head piece, indicated generally at 23, and the tip of the spindle projects through a hole 22a in said wall 22.

The head piece 23, in addition to the bottom wall 22, has a pair of spaced side walls 24 having upper edges with generally horizontal forward portions 25, rearward inclined portions 26 which are below the portions 25, and aligned openings between the

portions

25 and 26 for a transverse pivot pin 27. An inclined front wall 28 has an opening 29 therein, and there is an upturned rear flange 30. A seat support, indicated generally at 31, is pivotally mounted on the head piece 23 by Surrounding the pivot pin 27 within the head piece 23 is a plurality of split spring rings 38 which have aligned slots 39 formed therein to receive the finger 37 of the tension member 35. A cross'plate 40 in the head piece 23 and a pair of spacers 27a on the pivot pin 27 locate the split spring rings 38 in proper position in the head piece (FIGS. 2 and 4). A tension adjusting member 41 has a hooked rear finger 42 also received in the aligned slots 39 (FIGS. 3 and 4) parallelto the finger 37 and is provided with an opening 43 adjacent its forward edge 44 receiving a hooked end 45 of a tension adjusting bolt 46. The bolt 46 has a screw threaded end portion 47 opposite the hooked end 45 which projects through the opening 29 in the inclined front wall 28 of the head piece. A tension adjusting knob 48 with an integral internally threaded nut 49 screws onto the threaded end portion 47 of the bolt 46.

' In use, the split spring rings 38 exert force through the tensioning member 35 to yieldably resist tilting movement of the seat support 31. When a user leans backward while sitting in the chair, the spider arms 32 connected by the tension member 35 pivot in a clockwise direction about the pivot pin 27, as seen in FIGS. 1 and 4. As the seat support 31 tilts, the finger 37 on the tensioning member 35 acts to flex the split spring rings 38. Rearward tilting movement of the support 31 is limited by engagement of the horizontal webs 33 with the inclined portions 26 of the sides 24 of the head piece. When the backward force is terminated, the split spring rings 38 return the seat support 31 to its normal position. Turning the knob 48 and nut 49 on the bolt 46 acts through the tension adjusting member 41 to spread the split spring rings 38 and increase the force required to tilt the seat support 31.

FIGS. 6 and 7 disclose an embodiment of a chair control assembly for a secretarial posture chair, with parts identical to those of the control assembly 20 being 100 numbers higher. This assembly utilizes a head piece 123 having a bottom wall 122 with a hole to receive the tip of a tapered end portion 121a of a spindle 121 of a chair base (not shown), said tapered end portion fitting in a forging 119. A seat support 131 includes spider arms 132 having horizontal webs 133 to receive a chair seat (not shown), and depending webs 134 are fixedly secured to side walls 124 of the head piece 123 as by rivets 1340 or welding.

A pivot pin 127 extends through the webs I34 and the side walls 124 to provide a pivotal axis for a rocker 151 which supports a chair back (not shown). Surrounding the pivot pin 127 is a plurality of split spring rings 138 having aligned slots 139 to receive a finger 142 of a tension adjusting member 141 that is engaged by an adjusting bolt 146 which is operatively connected to a tension adjusting knob 148 and integral nut.

The rocker 151 includes a pair of generally parallel arms 152 joined by a tension web 153 which has at its forward end a depending finger 154 received in the slots ofthe split spring rings 138. The rocker arms 152 have forward rounded end portions 155 provided with aligned openings to receive the pivot pin 127, and the end portions 155 act to contain the spring rings 138 therebetween and retain them on a cross plate 140 in the head piece. The rocker arms 152 have rear end portions 156 which contain aligned holes toward the rear and more forward holes. The rocker 151 is adapted to pivot about the pivot pin 127 to tilt the chair back relative to the seat, with the tilting action being limited by engagement of the rocker arms 152 on the upturned rear flange 130 of the head piece 123.

A swivel plate 159 supports the chair back (not shown) in a known manner for vertical adjustment relative to the seat and is pivotally mounted on the rocker 151 by aligned rivets 160 in the rearward aligned holes of the rocker arms. The swivel plate 159 may be pivoted on the rivets 160, and is locked in any desired angular relationship to the rocker 151 by a clamping bolt in the more forward holes of the rocker arms which impales slots 161 in the swivel plate and clamps the swivel plate in a known manner by the use of a handle nut 162.

The secretarial posture assembly operates in a substantially similar manner to the embodiments of FIGS. 1 to 4, except that the seat support 150 is fixed while the chair back and swivel plate 159 tilt with the rocker 151 about the pivot pin 127.

A third embodiment 320 of chair control assembly shown in FIGS. 8 to 10 is utilized with an executive posture type swivel chair having simultaneous differential motion of a chair seat and separate chair back (not shown). Elements in this embodiment identical to those in the first or second embodiments will have the same reference numerals in a 200 series. As in the previous embodiments, a spindle 221 has a tapered end portion received in a forging 219, and the tip end of the spindle impales a hole in a bottom wall 222 of a head piece 223. Spaced side walls 224 on the head piece have aligned openings to receive a pivot pin 227. The side walls 224 are also provided with aligned holes forward of the pivot pin to receive a pair of pivot rivets 271 for a seat support 272 which includes spider arms 273 the rear ends of which are connected by a cross strap 273a. A chair seat (not shown) is mounted on the spider arms and cross straps.

Each spider arm 273 has a horizontal web 274 and a depending web 275 with a forward hole for one of the pivot rivets 271. The pivot pin 227 does not extend through the depending spider arm webs 275 so the seat support pivots on the rivets 271. A set of split spring rings 238 surround the pin 227 and have aligned slots 239 receiving a finger 242 of a tension adjusting member 241 which is movable to vary the tension of the split spring rings by adjusting a knob 248 and integral nut on a threaded bolt 246.

A rocker 25!, substantially identical to the rocker 151 of FIGS. 6 and 7, has upright rocker arms 252 connected by a tension web 253 at the front of which is a down turned finger 254 that is received in the aligned slots 239 of the set of split spring rings 238. The rocker arms 251 have aligned holes at their forward end portions receiving the pivot pin 227 which provides a pivot axis for the rocker. The spring rings 238 are properly positioned by a cross plate 240 and by the forward end portions of the rocker arms 277.

To the rear of the rocker pivot axis is a pair of connecting links 280 each of which is pivotally connected to a rocker arm 252 by arivet 281 and to an upright spacer arm web 224 by a rivet 282, so that the spider arms move simultaneously with the rocker 251 but tilt through a smaller angle because of their longer pivot axis.

At the rear of the rocker 251 is a swivel plate 259 which is identical to the swivel plate 159, so that a back (not shown) may be adjusted both vertically and angularly relative to the rocker. Thus swivel plate 259 is pivoted on rivets 260 and may be locked to the rocker at any desired angle by a clamping bolt and handle nut 261.

Referring to FIG. 11, an alternate integral spring ring means 438 in the form of a split sleeve has a longitudinal slot 439 therein. The spring ring means 438 may be substituted for the set of spring rings utilized in any of the above described three embodiments; and when it is used the

cross plate

40, 140 or 240 may be omitted and internal bosses on the pin flanges 27a or on the

rocker arms

151 or 251 may be used to position the sleeve properly relative to the pivot pin, the tension finger and the tension adjusting finger.

As used in the specification and claims, the term "tilting chair control" is a generic term which is intended to include any chair having amember which tilts relative to a fixed base and is returned to a normal upright position by resilient biasing means.

The foregoing detailed description has been given for clear-- ness of understandin only, and no unnecessar limitations should be understoo therefrom, as some modi ications may be obvious to those skilled in the art.

I claim: 1. A tilting chair control assembly comprising, in combination:

a head piece adapted to be mounted on a chair base, said head piece having spaced, upright side walls; split spring ring means mounted in said head piece between said side walls, said spring ring means having a continuous transverse slot from end to end; tilting means pivoted on said head piece on an axis parallel to said slot, said tilting means including a tensioning member with tensioning finger means projecting into said slot adjacent one side thereof; and tension adjusting means operatively connected to said head piece, said tension adjusting means including adjusting finger means projecting into the slot adjacent the other side thereof, and means for moving the adjusting finger means to prestress the spring ring means. 2. The assembly of claim 1 in which the spring ring means consists of a single split sleeve.

3. The assembly of claim 1 in which the spring ring means consists of a set of narrow spring rings having aligned slots.

4. The assembly of claim 1 in which the tensioning finger means and the adjusting finger means each comprises a single transversely elongated flange extending from end to end of the spring ring means in facing relationship to one another.

5. The assembly of claim 1 in which the tension adjusting means includes a finger member and an adjusting screw member which are connected together by a hook on one of said members engaging an opening in the other of said members, and a hand wheel threadedly engaging said screw member.

6. The assembly of claim 5 in which the opening is in the finger member and the hook is on the screw member.

7. The assembly of claim 1 in which the pivot axis of the tilting means comprises a transverse pin which is substantially concentrically surrounded by the spring ring means.

8. The assembly of claim 1 which includes spaced plates between the side walls of the head piece which confine the spring ring means.

9. The assembly of claim 8 in which the pivot axis of the tilting means comprises a transverse pin which is substantially concentrically surrounded by the spring ring means and in which the spaced plates are mounted on the pin.

10. The assembly of claim 8 in which the tilting means comprises a rocker member having parallel depending side walls comprising the spaced plates.

11. The assembly of claim 1 which includes a cross plate in the head piece supporting the spring ring means.

Claims

1. A tilting chair control assembly comprising, in combination: a head piece adapted to be mounted on a chair base, said head piece having spaced, upright side walls; split spring ring means mounted in said head piece between said side walls, said spring ring means having a continuous transverse slot from end to end; tilting means pivoted on said head piece on an axis parallel to said slot, said tilting means including a tensioning member with tensioning finger means projecting into said slot adjacent one side thereof; and tension adjusting means operatively connected to said head piece, said tension adjusting means including adjusting finger means projecting into the slot adjacent the other side thereof, and means for moving the adjusting finger means to prestress the spring ring means.

2. The assembly of claim 1 in which the spring ring means consists of a single split sleeve.