MXPA06007274A - Chair with backward and forward passive tilt capabilities - Google Patents

Abstract

A chair with backward and forward passive tilt capabilities including a seat assembly, a back assembly, a frame assembly, a wheeled base, a pedestal and a tilt mechanism. The tilt mechanism includes first, second and third links, first, second, third and fourth pivot pins, brackets and a resilient deformable block. The first link connects the back assembly with the frame assembly by way of the first pivot pin and the seat assembly by way of the second pivot pin. The second link connects to the frame assembly with the third pivot pin and to the third link with the fourth pivotpin. When a chair occupant shifts his/her weight rearwardly to tilt the back assembly, the seat assembly lifts and the block is deformed and stressed. When the chair occupant leans forwardly, the seat assembly lowers and the back assembly tilts forwardly. Again, the block deforms. Once the occupant sits upright or leaves the chair, the deformed block induces a return force to place the chair in a neutral upright position.

Description

CHAIR WITH PASSIVE VOLTAGE CAPACITY I DID BACK AND FORWARD BACKGROUND OF THE INVENTION The present invention relates to a chair, with the ability to turn back and forth and, more particularly, to a synchronous office chair with passive back and forward turning capabilities, this chair is simply constructed, it is reliable and relatively cheap.

EXHIBITION OF THE INVENTION Many chairs, particularly office chairs, have a backward movement, activated by weight. By this it is understood that a user, who shifts his weight, is able to flip the back portion of the chair to a reclining position. When the user moves his weight back, to an upright position, or when the user deviates, the chair returns to its neutral position by itself. This phenomenon is often described as being "passive" When the user shifts his weight forward, a spring returns the backrest portion to the chair to its erect position. Some office chairs are arranged so that the seat portion also moves in response to the overturning of the backrest portion and is commonly referred to as being synchronous. Sometimes, the feel portion is fixed to the backrest portion, so it pivots around the same angle, and in other chairs, the seat portion is arranged to be lowered or raised to a different rate than the rate of decline of the seat. the back portion, which results in different angular movements of the back portion and the seat portion.

EXHIBITION OF THE INVENTION There is described here a chair, which has a synchronous movement of the backrest and seat assemblies, with passive back and forward turning capabilities, comprising a chair having a feel set, a backrest assembly, a frame set to support the set of feel and the backup set, a base and a pedestal, driven to the base, and connected to the frame assembly, a first link, operatively connected to the backup set, to the frame set and to a third link, a first pivot, connected to the frame set and to the first link, in which this first link is pivoted in relation to the frame set, a second pivot, connected to the first link and to the set of sent, a second link, connected operatively to the frame assembly and to a third link, a third pivot, connecting the frame assembly and the second link, a third link, operatively connected to the seat assembly and to the second link, a fourth pivot, connected to the second link and the third link, and an orientation member, mounted to the frame assembly and can be deformed when the chair is overturned. There are a number of advantages, features and objects achieved with the present invention, which are believed not to be available in the above related devices. For example, an advantage of the present invention provides a synchronous chair apparatus, which is arranged to allow passive turning both forward and backward of the chair. Other objects of the present invention are the provision of a chair with forward and reverse turning capabilities, which is constructed in a simple manner and is reliable. Another advantage of the present invention is that this back and forth chair, described here, is relatively inexpensive, easy to construct and efficient to assemble. Yet another advantage of the passive chair is that the tumbling movement of the chair results from a displacement of the weight of the user's body and the chair moves in synchronism, ie flips the backrest assembly causes the seat assembly to pivot, but to a different regime. A more complete understanding of the present invention and other objects and advantages and their characteristics will be obtained from a consideration of the following description of the preferred embodiments, read in conjunction with the accompanying drawing herein provided. Preferred embodiments represent examples of the invention, which are described herein in compliance with Title 35 of U.S.G. Section 112 (first paragraph), but the invention itself is defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front isometric view of a synchronous office chair that has the ability to passively flip forward and backward; Figure 2 is a side elevational view of the office chair shown in Figure 1, with the arm support assemblies removed; Figure 3 is an isometric view, with radially spaced pieces, of a frame assembly, a link and a pedestal of the office chair shown in Figures 1 and 2; Figure 4 is an isometric view of a resilient block and end struts; Figure 5 is a schematic elevation view of the resilient block in a neutral position; Figure 6 is an exaggerated, schematic elevation view of the resilient block in an upwardly tensioned position; Figure 7 is an exaggerated, schematic elevation view of the resilient block in a downwardly tensioned position; Figure 8 is a side elevation view of the chair, shown in Figure 1, where the backrest assembly of the chair is in an upright or neutral position; Figure 9 is a side elevational view of the chair shown in Figure 7, where the chair's backrest assembly is fully reclined or turned back and the seat assembly is slightly raised; Figure 10 is a side elevational view of the chair shown in Figures 7 and 8, where the backrest assembly is turned in a forward direction and the seat assembly has been lowered slightly; Figure 11 is a kinematic elevation view of the chair of Figures 1, 7 to 9, in an upright or neutral position; Figure 12 is a kinematic elevation view of the chair of Figures 1 and 9, in a complete reverse flip; and Figure 13 is a kinematic elevation view of the chair of Figures 1, 7 to 9, in an upturned position.

THE BEST WAY TO CARRY OUT THE INVENTION While the present invention is subject to several modifications and alternative constructions, the preferred embodiment shown in the various figures of the drawing will be described here in detail. It will be understood, however, that there is no intention to limit the invention to the particular mode, form or example, which are described herein. On the contrary, the intention is to cover all the modifications and equivalent structures and methods, and the alternative constructions that are within the spirit or scope of the invention, as expressed in the appended claims, according to Title 35, U.S.C. section 112 (second paragraph).

Referring now to Figures 1 and 2, m an office chair 10 is illustrated. This chair has a capacity of passive turning and synchronous movement of the seat and is activated by weight. In Figure 2, the chair is without the sets of the support arms for clarity. The office chair includes a backrest assembly 12, a seat assembly 14, a frame assembly 16, a base with casters 18 and an adjustable pedestal 20. This chair also includes an arm support pair 22, 24. The seat assembly 14 includes a seat substrate 23, a seat plate 25 and a seat cushion 26. The frame assembly includes an anvil 30, Figures 1 and 3, a hub, control handles 34, 36 and a tumbling lock mechanism 38,40. The office chair operates in the usual manner in which the backrest assembly can be bent or reclined and the frame assembly can be adjusted vertically to allow a user to select a comfortable height for the seat assembly. The chair also provides for the synchronous movement of the backrest and the seat trim assemblies. Thus when a user of the chair leans back, not only reclines the backrest assembly, but the set of feel also pivots in a predetermined relationship. The chair of the invention, described here, also turns passively backwards and forwards. Referring to the pending patent applications, assigned to the same successor as the present application, and entitled: "Support of chair arms, horizontally adjustable" Application No.101748, filed on December 30, 2003 (File No. 087522 -785329), "Support of the backrest of the chair with improved resilience and support", Application No. 10 / 750,576, filed on December 0, 2003 (File No. 087522): "Chair arm support, vertically adjustable", Application No. 10 / 749,010, filed on December 30, 2003 (File No. 087522-785347); "Chair with tumbling lock mechanism", Application No. 10 / 749,008, filed on December 30, 2003 (File No. 087522-785350). These requests describe other characteristics of the chair. All the descriptions of the applications, just mentioned, are incorporated here for reference. The mechanism for allowing the chair 10 to roll back, as well as forward, in an efficient manner, will be better understood with reference to Figures 2 and 3. This mechanism includes a first link 50, which forms at one end 52 part of the backrest assembly 12, pivotally connected at the other end portion 56 to the seat plate 25 and also pivotally connected between the two end portions to the frame assembly 16, specifically to the fork 30. A second link 62 on a portion 64 end, connected pivotally to the frame assembly 16, specifically to the hub 32, and the other end portion 66 to a third link 68. This third link 58 in turn has an end portion 70, pivotally connected to the second link 62 and the other end portion 72, fixed to the seat plate 25. A first pin 80 forms a first pivot and pivots the middle portion of the first link 50 to the frame 16. Another pin 82 forms a second pivot and pivots the feel assembly 14 to the first link 50. A third pin 84 forms a third pivot and pivotally connects the frame assembly 16 and the portion 64 of one end of the second link 62. A fourth pin 86 forms a fourth pivot and pivots the first end portion 70 of the third link 68 to the other portion of the third link 68. end of the second link 62. The first pivot pin 80 is located more rearwardly and upwardly than the second, third and fourth pivot pins 82, 84, 86, the second pin. 82 of pivot 82 is located further back and upwardly than the third and fourth pivot pins 84, 86 and the third pivot pin 84 is located further back and upward than the fourth pivot pin 86. The mechanism also includes an orientation member, in the form of a rubber block 90, Figure 4-7. The block is between the second links 62 and a portion attached to the frame assembly, which is thus fixed, and the other end portion attached to the third links, which can be moved with the pivot of the feel set. The second link includes spaced parallel bars (Figure 3), which surround the orientation member 90, which can be deformed. When it deforms, a tension is induced in the block to return by itself to the unstressed position. In the illustrative embodiment, the orientation member is the block of resilient material formed of rubber. Any suitable material can be used as long as it acts like rubber. As shown in Figures 4 and 5, the block has a neutral, unstressed position, when the chair is positioned as shown in Figure 2. When it deforms under an applied force, such as a weight shift of a user of the chair, the block develops a counter-force due to the tension that tends to orient the block and thus the backrest of the chair to its neutral positions.

It will be understood that other devices that generate energy may be used, such as springs, a torsion spring or the like. The rubber or rubber type material, however, is preferred, due to the damping characteristics, its ease of attachment to the chair, its characteristic of not producing noise and its ability to sustain a large deformation, due to its highly elastic nature . The rubber also has the advantage of durability and high energy in relation to its size or volume. Thus, the block is compact. A first end portion 92 of the resilient block 90 is attached to a fixed clamp 94, which is attached to the frame assembly 16 and the other end portion 96 of the resilient block is connected to a clamp 97, which is connected to the third. link 68. When the second and third link are moved in response to the back and forward flipping of the backrest assembly, and the synchronous movement of the seat assembly due to the displacement of the chair user from its weight, the resilient block is deformed, establishing an orientation force that seeks to return the block to its neutral, unstressed position. When a user moves against the backup set, the block is distorted as shown in Figure 6. When the user moves forward, the block is distorted as shown in Figure 7. When the user shifts his weight from new to a neutral or erect position, or when the user moves away from the chair, the resilient block will return the chair to its erect position. The actual force induced in the block is a function of the material of the block, the geometry of the block and the hardness of the block. To better understand the operation of the office chair, it should be understood that the frame assembly 16 is stationary during use, then being vertically adjusted for the comfort of a specific chair user. The first pivot pin 80 and the third pivot pin 84, which are mounted to the frame assembly, allow rotation of the other elements, but they by themselves remain in a fixed location. The second pivot pin 82 and the fourth pivot pin 86, however, are arranged so that each of them can move in an arc in response to the movement of the links to which they are attached. The movement of the links and the pivot pins causes the resilient block to deform or distort and as shown schematically in Figures 6 and 7, in sympathy with a neutral position shown in Figures 4 and 5. The deformation of the resilient block 90 creates shear stresses in the block, which, in turn, create an orientation force to return the block to its neutral position. It is this force of orientation plus the arrangement of the links and pivots, which allow the chair to turn back and forth in a passive arrangement, simply by a user of the chair that displaces the weight of his body. The passive tumbling can be appreciated with reference to Figures 8 to 10. In Figure 8, the chair 10 is shown in a neutral or upright position. In this position, anyone occupying the chair or user of the chair does not move his body backwards or forwards. Under such circumstances, the resilient block 90 has not been deformed, so no cutting tension is induced in the block. A small cross 100 is drawn above the second pivot 82 and represents the approximate position of a hip joint of the user of the chair. Referring to Figure 9, the chair 10 is in a reclining position, which occurs when the occupant of the chair tilts backward, thus forcing the backrest assembly to recline. It can be seen that when the backrest assembly of the chair reclines, the first end portion 52 of the first link 50, which is connected to the backrest assembly 12, rotates counterclockwise or downward, causing the opposite end portion 54 pivots upward and thus will marginally raise the seat assembly. The elevation of the seat assembly causes the third link 68 to move upward, which in turn, pulls the fourth pivot pin 86 upward, so that the end portion 66 of the second link 68 is raised. This movement also distorts the resilient block. In the neutral position (Figure 8) The second link 62 is arranged at an angle of approximately twenty-three degrees from the horizontal reference. This can be compared to the disposition of the Figure 9, where the second link is set to approximately zero fat from a horizontal reference (the angles are measured from the third pivot pin 84).

Only a marginal elevation of the seating assembly is desired, in order to maintain the relative position of the occupant to the related floor or work surface, in the reclined position, shown in Figure 9, the resilient block is distorted, as shown in the Figure 6, thus inducing the orientation force to return the block and the chair to the positions shown in Figures 5 and 8, respectively. Such a return will occur once the user of the chair moves forward or moves away from the chair. In an analogous way, a user can lean forward in the chair. For example, while performing a computer task or writing or reading on the desktop or other work surface. Turning in front of the chair is shown in Figure 10, where the front portion of the seat assembly is pivoted downward, causing the third link to push the fourth pivot pin 86 downward. This movement increases the angle of the second link 62 from a horizontal reference line to approximately forty degrees. The same rotation forward of the chair assembly causes the second pivot pin 82 to move downward, causing the end portion 54 of the first link 50 to follow. Because the first link is pivoted to the frame assembly 16 by the first pivot pin 80, downward movement of the end portion 54 of the first link causes the opposite end portion 52 to rise. This causes the backup assembly to be flipped forward. Thus, the chair follows the user in an automatic or passive way simply, because the user has moved his body forward. Turning forward causes the resilient block to deform downward, as shown in Figure 7, which induces the orientation force to return the block to the neutral position, shown in Figure 5. Thus, with such a reclined position, a Once the user shifts their weight upward or if the user gets up from the chair, the resilient block will return the chair to the neutral or upright position, shown in Figure 8. Referring now to Figures 11 to 13, they are shown kinematic views of the chair. These kinematic views are analogous to the views of the chair shown in Figures 8 to 10. The chair, when in its neutral position (Figure 11), placed the backup assembly 12 at an angle to a vertical reference line 101 of approximately sixteen degrees. The angle between the backrest assembly 12 and the seat assembly 14 is approximately one hundred and two degrees. In this arrangement, the seat is positioned at an angle of about four degrees from a horizontal reference line 102, the front of the seat has an elevation of about 5.67, and the rear portion of the feel set has an elevation of about 4.46. The second link 62 is arranged at an angle of about thirty-five degrees from the horizontal reference line. When the backrest assembly reclines (Figure 12), the backrest assembly 12 has an angle of about thirty-six degrees from the vertical reference line 101, the angle between the backrest assembly 12 and the seat assembly 14 is about one hundred thirty degrees and the seat assembly 14 has an angle of about five and one fifth of degree, from the horizontal reference line 102. The front portion of the seat assembly has an elevation of about 6.67 and the rear portion of the seat assembly has an elevation of about 5.03. The angle of the second link 62 is about zero degrees from the horizontal reference line 102. When the chair is turned forward (Figure 13), the backup assembly 12 has an e of about ten degrees of the vertical reference line 101, and the e between the backup assembly 12 and the seat assembly 13 is about ninety-seven degrees. The seat e is about three degrees from the horizontal reference line 102 with a front seat elevation of about 5.19 and a rear seat elevation of about 4.3. The second link 62 has an e of about fifty-five degrees from the horizontal reference line 102. More precise measurements are indicated in Figures 11 to 13, according to the es and elevations. The kinematic figures also show the synchronic movement of the chair. For example, a counter-clockwise pivot of the rear set of about twenty degrees induces a synchronous pivot of about 1.2 grams in the set of feel. Similarly, a pivot in the direction of clock rotation of the back set for about six degrees induces a synchronous pivot of about two degrees in the seat assembly. The preferred distance between the first and second pivot pins 80, 82, is about 5.72 cm and the distance between the third and fourth pivot pins 84, 86 is about 5.08 cm. In the neutral position, the first pivot pin 80 is about 1.27 cm above and 5.512 cm behind the second pivot pin 82, about 9.09 cm behind the third pivot pin and about 16.38 cm above and 13, 77 behind the fourth pivot pin 86. The e of the first link 50 is about fifteen degrees from a horizontal reference line and the e of the second link 62 is about 23.2 degrees from a horizontal reference line. In the full reclined position, the first pivot pin 80 is shown at the same height and by 5.72 cm behind the second pivot pin 82, about 14.38 cm above and 9.09 cm behind the third pivot pin 84, and about 14.38 cm up and 14.17 cm behind the fourth pivot pin 86, the e of the first link 50 is about zero fat from the horizontal reference line and the e of the second link 62 is about zero degrees from the horizontal reference line . In the full turn forward, the first pivot pin 80 is about 2.51 cm above and 5.13 cm behind the second pivot pin 82, about 14.38 cm above and 9.09 behind the third pivot pin 84, and about 17.60 above and 13.03 cm behind the fourth pivot pin 86. The e of the first link 50 is about twenty-six degrees from the horizontal reference line and the second link 62 is about 39.2 degrees from a horizontal reference line. During the operation of the chair, a neutral position is assumed by the chair when there is no distortion of the resilient block and thus no orientation force induced in the mechanism of the chair. To recline, a user merely shifts his weight backward, causing the resilient block to be deformed, as shown in Figure 6. The user's hip joint 100 represents the pivot point backward or forward of the weight shifts. This induces an orientation force to return the chair to its neutral position once the user feels erect or leaves the chair. The same mechanism allows the user to simply turn forward by leaning forward on the chair as when performing a task on a desk. This movement forward of the weight of the user causes the resilient block to be deformed, as shown in Figure 7, thus inducing an out of orientation return. Once again, when the user moves his weight away from the desk, the chair will tend to return to its neutral position and will return definitively to its neutral position if the user of the chair gets up from it. It can now be appreciated that the office chair has a mechanism that allows the chair to respond merely to unclamping the occupant's weight to flip back or forward. In both cases, once the weight is removed, the chair returns to its neutral position. It can also be appreciated that the mechanism to achieve this passive movement is relatively simple, very reliable and generally cheap. The above specification describes in detail a preferred embodiment of the present invention. Other examples, modalities, modifications and variants, according to the literal language of the claims and the doctrine of equivalents, within the scope of the invention, defined by the appended claims. For example, the configuration or design of the seat assembly and the backrest assembly may change and the chair will still be considered as an equivalent structure. The length and location of the links and the locations of the pivot pins can also change somewhat and the chair will still be considered as an equivalent structure and will still be within the literal language of the claims in their broadest sense, even if the angles and elevations are somewhat altered. Still other alternatives will also be equivalent, as well as many new technologies. There is no desire or intention to limit, in any way, the application of the doctrine of equivalents to limit or restrict the scope of the invention.

Claims (9)

1. CLAIMS 1. A chair, which has synchronous movement of the backrest and seat assemblies, and passive back and forward turning capabilities, this chair comprises: a chair, which has a seat assembly, a backrest assembly and a set of frame, to support said seat and backrest assemblies; a first link, operatively connected to said backup assembly, to said frame assembly and said seat assembly; a first pivot, connecting said frame assembly and said first link, wherein said first link pivots relative to the frame assembly; a second pivot, connecting said first link and said seat assembly, wherein said first link pivots relative to said seat assembly, whereby this second pivot is placed approximately under a hip joint of the occupant of the chair; a second link, operatively connected to said frame assembly and to a third link; a third pivot, connecting said frame assembly to said second link; a third link, operatively connected to said seat assembly and said second link; a fourth pivot, connecting said second link to said third link; and an orientation member, mounted to said frame assembly and which is deformable; said first pivot is located more backward and upward than said second, third and fourth pivots; said second pivot is placed more backward and upwardly than said third and fourth pivots; and said third pivot is placed more backward and upwardly than said fourth pivot.
2. 2. A chair, which has a synchronous movement of the back and seat assemblies and passive turning capabilities back and forth, said chair comprises: a chair, which has a seat assembly, a backrest assembly and a frame assembly, for supporting said seat and backrest assemblies, - a first link, operatively connected to said backrest assembly, to said frame assembly and said seat assembly; a first pivot, connecting said frame assembly and said first link, wherein said first link pivots relative to the frame assembly; a second pivot, connecting said first link and said seat assembly, wherein said first link pivots relative to said seat assembly, whereby this second pivot is placed approximately under a hip joint of the occupant of the chair; a second link, operatively connected to said frame assembly and to a third link; a third pivot, connecting said frame assembly to said second link; a third link, operatively connected to said seat assembly and said second link; a fourth pivot, connecting said second link to said third link; and an orientation member, mounted to said frame assembly and which is deformable; the first pivot is fixed in position relative to said frame assembly; the second pivot can be moved in relation to said frame assembly; the third pivot is fixed in position relative to said frame assembly; the fourth pivot can be moved in relation to said frame assembly; said first pivot is located more backward and upward than said second, third and fourth pivots; said second pivot is placed more backward and upwardly than said third and fourth pivots; and said third pivot is placed more backward and upwardly than said fourth pivot.
3. 3. The chair of claim 2, wherein said seat assembly moves at a lower rate than said backrest assembly.
4. 4. The chair of claim 2, wherein: the movement of said backrest assembly causes the first link to move said seat assembly .; the movement of said seat assembly pivots said second link; and this pivoting of the second link causes said orientation member to deform.
5. 5. The chair of claim 4, wherein: the movement of said seat assembly induces tension in said orientation member.
6. 6. The chair of claim 5, wherein: the movement of said seat assembly from an upright neutral position induces the deformation of said orientation member and an orientation force to return said seat assembly to said upright neutral position.
7. 7. The chair of claim 6, wherein: said first link is connected at a first end portion to said backrest assembly, at a second end portion to said sit assembly and between said first and second end portions to said frame central; and said third link is connected in a first end portion to said front portion of said seat assembly and in a second end portion to said second link.
8. 8. A chair, which has a synchronous movement of the backrest and seat assemblies, and passive back and forward turning capabilities, this chair comprises: a chair, which has a seat assembly, a backrest assembly and a frame assembly, to support said seat and backrest assemblies; a first link, operatively connected to said backup assembly, to said frame assembly and said seat assembly; a first pivot, connecting said frame assembly and said first link, wherein said first link pivots relative to the frame assembly; a second pivot, connecting said first link and said seat assembly, wherein said first link pivots relative to said seat assembly, whereby this second pivot is placed approximately under a hip joint of the occupant of the chair; a second link, operatively connected to said frame assembly and to a third link; a third pivot, connecting said frame assembly to said second link; a third link, operatively connected to said seat assembly and said second link; a fourth pivot, connecting said second link to said third link; and an orientation member, mounted to said frame assembly and which is deformable; in that from an upright position, a displacement of the weight by an occupant of the chair causes that said set of felt to turn downwards, whereby it flips the backrest assembly forward towards the seat assembly; from an upright position, a displacement of the weight by an occupant of the chair causes the said backrest assembly to turn backward, and said seat assembly to elevate it; the movement of said backup set causes the first link to move said seat set; the movement of said set of pivot said second link; the pivoting of said second link causes said orientation member to deform; the movement of said seat assembly induces tension in said orientation member; the movement of said set of felt from the upright position induces the deformation of said orientation member and an orientation force to return said seat assembly to said upright central position, said first pivot is fixed in position relative to said set of framework; said second pivot can be moved relative to said frame assembly; said third pivot is fixed in position relative to said frame assembly; said fourth pivot can be moved relative to said frame assembly; and said first pivot is placed more rearwardly and upwardly than said second, third and fourth pivots, said second pivot being placed more rearwardly and upwardly than said third and fourth pivots; and said third pivot is placed more backward and upwardly than said fourth pivot.
9. 9. The chair of claim 8, wherein: said first link is connected at a first end portion to said backrest assembly,,, at a second end portion to said seat assembly and between said first and second end portions a said frame set; and said third link is connected in a first end portion, to a front portion of said seat assembly and in a second end portion to said second link.