Positioning device for chair

[0001] 1. Field of the Invention

[0002] The present invention relates to a positioning device for a chair and, more particularly, to a positioning device for a leisure chair with an inclinable seat.

[0003] 2. Description of the Related Art

[0004] A typical leisure chair includes a base, a rod fixed on the base, and an inclinable seat mounted on the base and pivotable to an inclined angle relative to the seat. A positioning device in the form of a knob is releasably mounted to the rod and fixed to the seat to move therewith. When it is desired to move the seat to an inclination angle, the knob is firstly disengaged from the rod to allow the seat to be pivoted to a desired inclined angle. Then, the knob is reengaged with the rod to fix the seat in the inclined angle. However, operation of the knob is inconvenient, and the knob can not provide a reliable positioning effect.

[0005] Thus, a need exists for a positioning device for a chair with an inclinable seat that can be operated in a simple manner while providing a reliable positioning effect.

[0006] The present invention solves this need and other problems in the field of positioning of a chair seat by providing, in a preferred form, a positioning device including a clamping seat having first and second clamping members pivotably connected together. Each of the first and second clamping members includes a clamping portion on an end thereof. The clamping portions of the first and second clamping members are adapted to be mounted around a fixed rod of a chair. The first clamping member includes a first through-hole, and the second clamping member includes a second through-hole. A spring is mounted between the first and second clamping members to bias the clamping portions to an open state not clamped on the fixed rod, allowing movement of the clamping seat along the fixed rod. The first clamping member further includes a coupling portion adapted to be fixed to a side of an inclinable seat of the chair that is moveable relative to the fixed rod. A positioning block is mounted to the second clamping member and includes first and second sides and a third through-hole extending from the first side through the second side of the positioning block and aligned with the second through-hole of the second clamping member. The second side of the positioning block includes a protrusion. An adjusting rod includes a coupling seat and a handle fixed to the coupling seat to move therewith. The coupling seat includes first and second sides and a fourth through-hole extending from the first side through the second side of the coupling seat. The first side of the coupling seat includes a positioning groove having a low-profile section, a high-profile section, and a transition section between the low-profile section and the high-profile section. The handle is pivotable between a release position and a clamping position. A first coupling rod is extended through the first, second, third, and fourth through-holes. The protrusion of the positioning block is received in the positioning groove of the coupling seat and engaged with one of the low-profile section and the high-profile section.

[0007] When the handle is in the release position, the protrusion of the positioning block is engaged with the low-profile section, and the first and second clamping members are in an open state under the action of the spring, so that the clamping portions of the first and second clamping members are not clamped on the fixed rod, allowing movement of the clamping seat along the fixed rod and allowing movement of the inclinable seat relative to the fixed rod.

[0008] When the handle is in the clamping position, the protrusion of the positioning block is engaged with the high-profile section, and the first and second clamping members are in a clamping state, so that the clamping portions of the first and second clamping members are clamped on the fixed rod, not allowing movement of the clamping seat along the fixed rod and not allowing movement of the inclinable seat relative to the fixed rod.

[0009] The present invention will become clearer in light of the following detailed description of an illustrative embodiment of this invention described in connection with the drawings.

[0021] All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood.

[0022] A positioning device according to the preferred teachings of the present invention is shown in the drawings and generally includes a clamping seat 1, a positioning block 2, an adjusting rod 3, and a coupling mechanism 4.

[0023] According to the preferred form shown, the clamping seat 1 includes first and second clamping members 11 and 12 each having a pivotal portion 111, 121 on an end thereof. A pin 114 is extended through the pivotal portions 111 and 121 to allow relative pivotal movement between the first and second clamping members 11 and 12. Each of the first and second clamping members 11 and 12 further includes a clamping portion 112 and 122 on the other end thereof for clamping on a fixed rod 5 of a chair such as a leisure chair having an inclinable seat 6 (FIG. 4). Each of the first and second clamping members 11 and 12 further includes a through-hole 113 and 123 extending from an outer side 118, 128 thereof through an inner side 119, 129 thereof that is spaced from the inner side 118, 128 in a longitudinal direction. The through-hole 113 is intermediate and spaced from the pivotal portion 111 and the clamping portion 112. The through-hole 123 is intermediate and spaced from the pivotal portion 121 and the clamping portion 122 and includes an enlarged section 124 in the outer side 129 of the second clamping member 12. The inner sides 119 and 129 face each other. Furthermore, two springs 115 are mounted between the inner sides 119 and 129 of the first and second clamping members 11 and 12 to bias the clamping portions 112 and 122 away from each other to an open state, so that the fixed rod 5 is not clamped by the clamping portions 112 and 122. In the most preferred form shown, the inner face 119 of the first clamping member 11 includes two first receptacles 117, and the inner face 129 of the second clamping member 12 includes two second receptacles 127 aligned with the first receptacles 117. Each of two ends of each spring 115 is received in one of the first and second receptacles 117 and 127. Further, the first clamping member 11 includes a coupling portion 116 fixed to a side of the inclinable seat 6.

[0024] According to the preferred form shown, the positioning block 2 includes a first side fixed in the enlarged section 124 of the through-hole 123 of the second clamping member 12. The positioning block 2 further includes a second side outside of the enlarged section 124. Furthermore, the positioning block 2 includes a through-hole 21 extending from the first side thereof and through the second side thereof and aligned with the through-hole 123 of the second clamping member 12. Two protrusions 22 are formed on the second side of the positioning block 2 and surround the through-hole 21 and the positioning block 2.

[0025] According to the preferred form shown, the adjusting rod 3 includes a coupling seat 31 and a handle 32 fixed to an outer periphery of the coupling seat 1. The coupling seat 31 includes first and second sides 34 and 36 spaced in the longitudinal direction. The coupling seat 31 further includes a through-hole 311 extending from the first side 34 through the second side 36. In the most preferred form shown, the first side 34 of the coupling seat 31 includes two annularly spaced positioning grooves 312 each having a low-profile section 313, a high-profile section 314, and an inclined transition section 315 between the low-profile section 313 and the high-profile section 314. Furthermore, a compartment 316 is formed in the second side 36 of the coupling seat 31 and in communication with the through-hole 311 of the coupling seat 31.

[0026] According to the preferred form shown, the coupling mechanism 4 includes first and second coupling rods 41 and 42, a bearing 43, a washer 44, and an end cap 45. The first coupling rod 41 is extended through the through-holes 113, 123, 21 and 311 respectively of the first clamping member 11, the second clamping member 12, the positioning block 2, and the coupling seat 31. The first coupling rod 4 includes an end having a screw hole 411. The bearing 43 is received in the compartment 316 and in contact with a bottom wall of the compartment 316. The bearing 43 includes a central hole 431 through which the first coupling rod 41 extends. The washer 44 is received in the compartment 316 and includes a central hole 441 through which the first coupling rod 41 extends. The second coupling rod 42 is received in the compartment 316 and includes a threaded portion 421 on an end thereof threadedly engaged with the screw hole 411. The second coupling rod 42 further includes an enlarged head 422 on the other end thereof. The enlarged head 422 presses against the washer 44, which in turn, presses against the coupling seat 31 and the positioning block 32, so that the protrusions 22 of the positioning block 2 are received in the positioning grooves 312 of the coupling seat 31. The end cap 45 is fixed to the second side 36 of the coupling seat 31 to cover the compartment 316.

[0027] When the first and second clamping members 11 and 12 is in the open state (FIGS. 5-7) under the action of the springs 115, the clamping portions 112 and 122 do not clamp on the fixed rod 5, so that the clamping seat 1 can move along the fixed rod 5 to adjust the inclination angle of the inclinable seat 6 to which the first clamping member 11 is fixed via the coupling portion 116. In the open state, the handle 32 is in a release position, and each protrusion 22 of the positioning block 2 is engaged with the low-profile section 313 of one of the positioning grooves 312.

[0028] When the inclinable seat 6 reaches the desired inclination angle, the handle 32 is pivoted to a clamping position, and each protrusion 22 of the positioning block 2 is moved from the low-profile section 313 through the transition section 315 to the high-profile section 314. The second clamping member 12 is moved away from the adjusting rod 31 and, thus, pivots toward the first clamping member 11. Thus, the first and second clamping members 11 and 12 are moved to a clamping state securely clamped on the fixed rod 5. Movement of the clamping seat 1 along the fixed rod 5 is, thus, prohibited. Accordingly, the inclinable seat 6 is fixed in the inclination angle relative to the fixed rod 5.

[0029] The bearing 43 includes balls that can roll on the bottom wall of the compartment 316 of the coupling seat 31 during pivotal movement of the handle 32, reducing friction and allowing smooth operation. The positioning block 2 can include only one protrusion 22, and the coupling seat 31 can include only one positioning groove 312. The clamping seat 1 can include only one spring 115 between the first and second clamping members 11 and 12.

[0030] Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.