Rocking and gliding mechanism

Abstract: A rocking and gliding chair has a seat (14) carried on a spreader frame (26) on top of a central post (30) mounted on a base (11), the post incorporating a swivel mechanism. The spreader frame supports unitary first and second depending links (42,44) which pivot on parallel horizontal axes and which at the lower ends are pivoted to a pair of laterally spaced lower support links (56,58). Side panels (60,62) on the lower support links carry the seat platform (22) and the seating portion of the chair.

Description: This invention relates to a mechanism for providing rocking and gliding movement to a chair or other seating arrangement, and also to a seating arrangement that incorporates such mechanism. Simple rocking chairs have been known since time immemorial, and in more recent decades various chair configurations have been available having mechanisms that accommodate rocking movements of the chair against the force of a return spring, often in combination with a swivel arrangement. A swivel arrangement in combination with a gliding mechanism is shown in US 5630646 (Trimble). Chairs have also been developed which accommodate a gliding movement and a rocking movement as well as combinations of these two movements. One example of such a chair is shown in US 4108415 to Hauray et al. US 5427433 and 5653507 to Holobaugh disclose upholstered armchairs that combine a rocking and gliding mechanism together with a swivel base. The prior art rocking and gliding mechanisms tend to be configured as four-bar linkages on opposite sides of the chair, there being two downwardly oriented links laterally spaced at the front of the chair and two downwardly oriented links laterally spaced towards the rear of the chair. These known mechanisms tend to be very utilitarian and unsightly in appearance, and in the Holobaugh patents for example are completely hidden on the underside of the chair. According to the present invention there is provided a rocking and gliding mechanism for a chair, comprising a support member extending upwardly, a spreader frame carried on the upper end portion of said support member and having a front end that defines a forward pivot mount and a rear end that defines a rearward pivot mount, a unitary front link having an upper end adapted to be pivotally mounted to said forward pivot mount and having a lower end that defines an elongated bottom front bearing member, a unitary rear link having an upper end adapted to be pivotally mounted to said rearward pivot mount and having a lower end that defines an elongated bottom rear bearing member, first and second lower links, each of said lower links having a front end and a rear end respectively, the front end of said first lower link and the front end of said second lower link being pivotally mounted to said bottom front bearing member about a pivot axis that extends along said bottom front bearing member, said bottom front bearing member extending substantially continuously from the front end of said first lower link to the front end of said second lower link; and a seat support structure comprising a pair of upwardly oriented side frames, each having a lower portion attached to a respective one of said lower links and an upper portion that is attachable to a seat of a chair, whereby said seat is movable in a gliding and rocking fashion relative to the ground. A swivel mechanism may be interposed between the said spreader frame and the said support member to enable the seat of a chair to be swivelled about a generally upright axis. The said front and rear pivot links are preferably generally planar, each having a lateral extent of at least about half of the lateral spacing between the said side frames. Likewise the lower portion of each side frame is preferably also planar and has a length in the front to rear direction of at least about half of the length of the lower support links. Arm rests may be included in upwardly extended portions of each side frame, extending forwardly from the back of the chair. It is to be understood that as used herein, the word "chair" is intended to be broadly interpreted as including not just seats intended for occupation by one person, but also wider seats such as love-seats, sofas and the like that can accommodate two or more people sitting side-by-side. An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, in which:- Figure 1 is a front perspective view of a chair in accordance with the present invention; Figures 2A, 2B and 2C are schematic views illustrating the rocking and gliding action afforded by the chair linkage; Figure 3 is a top perspective view from one side showing the chair base and the support mechanism for providing the rocking and gliding action; Figure 4 is a front perspective view corresponding to Figure 3; and Figure 5 is a side perspective view as seen from the right side of Figure 4. Referring to Figure 1, there is shown an upholstered chair 10 having a base 11 and a seating part 12, the latter comprising a generally horizontal padded seat 14 and a padded backrest 16. As illustrated, the base 11 is of large diameter circular form having a convex upper surface. At each side of the seat 14 is an upright armrest 20. The seat is carried on a seating platform 22 at each side of which is an outwardly and upwardly extending wing 24 which provides a support for the corresponding armrest 20. The platform 22 is attached to the tops of a pair of side frames 60, 62. A spreader frame 26 is carried in a swivel mounting 28 at the top of a vertical post 30 mounted on the base 11. By means of the swivel mounting 28, the spreader frame 26 together with the entire seating structure can be swivelled about the vertical axis 31 of the post 30. The spreader frame 26 is a hollow rectangular steel member, and as seen more particularly in Figures 3 through 5, extends horizontally above the post having welded to the opposite ends thereof a front bearing tube 32 and a rear bearing tube 34. As is clearly shown in Figure 3, the horizontal spacings between the bearing tubes 32,34 and the post 30 are unequal, the rear bearing tube 34 being much closer to the post 30 than the front bearing tube 32. Each bearing tube 32,34 extends horizontally transversely to the length of the spreader frame 26 and forms a bearing support for respective pivot pins 36,38 the ends of which extend beyond both ends of the respective bearing tubes and form pivot supports for a pair of bearing knuckles 40 provided at the upper ends of a unitary front link 42 and a unitary rear link 44 respectively. The lower ends of the front and rear links 42, 44 have attached thereto elongate horizontal bearing tubes 46,48 each of which extends laterally beyond the sides of the respective unitary link and supports a corresponding pivot pin 50,52 the ends of which project beyond the bearing tube on each side and are received in corresponding bearing knuckles 54 which are integrally formed at the respective front and rear ends of a pair of lower support links 56,58. Each support link is of hollow steel box section, the knuckles 54 being integrally attached as by welding to the front and rear ends of the links 56 and 58, and these links having an upwardly convex curvature along their length as indicated in Figures 2 and 5 to reflect the convex curvature of the top of the base 11. Each of the support links 56,58 is attached to the lower end of an upstanding side frame 60,62 respectively, the upper ends of the side frames being at an angle to the horizontal, sloping slightly upwardly in the forward direction and having projecting mounting plates 64 thereon for attachment to the seating platform 22 by means of threaded fasteners (not shown). From the foregoing, it will be appreciated that the spreader bar 26 together with the front link 42, the rear link 44 and the lower support links 56,58 constitutes a four bar linkage with pivotal interconnections at the corners. The front and the rear links 42,44 are of equal length and converge downwardly since the lower support links 56,58 are shorter than the spreader frame 26. Thus, the seat 12 that is supported through the platform 22 and the mounting plates 64 on the side frames 60, 62 is movable in a rocking and gliding motion with respect to the base 11. This motion is illustrated in Figures 2A, 2B and 2C, in which views the front of the chair faces to the left. Figure 2A shows the neutral position assumed by the linkage when the chair is at rest. When the chair is rocked forwardly, the linkage assumes the position indicated in Figure 20, wherein the lower support links 58,56 are forwardly displaced, this being accommodated by clockwise pivotal movement of the front and rear links 42,44 about their respective pivot pins 36,38. On the other hand, when the chair is rocked rearwardly, the linkage is displaced as shown in Figure 2C. As has been noted above, the spreader frame 26 is not centrally mounted on the post 30, but rather is offset forwardly thereon so that in the rest position as seen in Figure 2A, the pivot pin 52 is spaced further from the vertical post 30 than is the pivot pin 50. Forward rocking movement as illustrated in Figure 2B is limited by abutment of the rear bearing tube 48 against the post 30, and to cushion any impact a resilient bumper pad is carried centrally on the front side of the rear bearing tube 48. Suitable bearings such as nylon bushings (not shown) are interposed between the pivot pins 36,38,50,52 to provide a smooth pivot action so that the chair seat 12 can be rocked and glided with an exceptionally smooth action. The structures of the front and rear links 42,44 and of the side frames 60,62 are provided as metal fabrications, as is best seen in Figure 3. As seen here, the side frame 62 comprises two vertical metal straps 68,70, the lower ends of which are welded to the lower support link 60 and the upper ends of which are welded to an inclined metal strip 72, the ends of which constitute the mounting plates 64. A decorative outer panel 74 is attached to the metal straps 68,70 by screws. The side frame 60 is of similar construction. Likewise, the front and rear links 42,44 are of welded metal fabrication, the front link comprising a pair of metal straps 78, the lower ends of which are welded to the lower bearing tube 46 and the upper ends of which have welded thereto the knuckles 40. A decorative panel 80 is attached to the straps 78 by screws and forms a unitary structure therewith. The rear link 44 is of similar construction to the front link. The decorative panels 74,80 can be of any desired finish. In the example illustrated, these panels and the upper side of the base 11 are of wood and are all finished with a rich wood grain appearance.

Claims: A rocking and gliding mechanism for a chair, comprising: a support member (30) extending upwardly; a spreader frame (26) carried on the upper end portion of said support member and having a front end (32) that defines a forward pivot mount and a rear end (34) that defines a rearward pivot mount; a unitary front link (42) having an upper end adapted to be pivotally mounted to said forward pivot mount and having a lower end (46) that defines an elongated bottom front bearing member; a unitary rear link (44) having an upper end adapted to be pivotally mounted to said rearward pivot mount and having a lower end (48) that defines an elongated bottom rear bearing member; first and second lower links (56, 58), each of said lower links having a front end and a rear end respectively, the front end of said first lower link and the front end of said second lower link being pivotally mounted to said bottom front bearing member about a pivot axis that extends along said bottom front bearing member, said bottom front bearing member extending substantially continuously from the front end of said first lower link to the front end of said second lower link; all of said pivot mounts defining substantially parallel pivot axis; and a seat support structure comprising a pair of upwardly oriented side frames (60, 62), each having a lower portion attached to a respective one of said lower links (56, 58) and an upper portion that is attachable to a seat (14) of a chair, whereby said seat is movable in a gliding and rocking fashion relative to the ground. A mechanism as claimed in claim 1, wherein said bottom front bearing member has a longitudinal axis coincident with said pivot axis. A mechanism as claimed in claims 1 or 2, wherein said bottom front bearing member comprises a pair of pivot pins (50, 52), said pivot pins projecting from respective ends of said bottom front bearing member and penetrating the respective front ends of said first and second lower links (56, 58). A mechanism as claimed in any of claims 1 to 3, wherein the rear end of said first link (56) and the rear end of said second link (58) are pivotally mounted to said bottom rear bearing member about a pivot axis that extends along said bottom rear bearing member, said bottom rear bearing member extending substantially continuously from the rear end of said first lower link to the rear end of said second lower link. A mechanism as claimed in claim 4, wherein said bottom rear bearing member comprises a pair of pivot pins (50, 52), said pivot pins projecting from respective ends of said bottom rear bearing member and penetrating the respective rear ends of said first and second lower links (56, 58). A mechanism as claimed in any of claims 1 to 5, wherein each of said unitary front and rear links (42, 44) is generally planar and has a lateral extent of at least about half of the lateral spacing between said side frames (60, 62). A mechanism as claimed in any of the preceding claims, including a swivel mechanism (28) interposed between said spreader frame (26) and said support member (30), whereby said seat (14) can be swiveled about a generally upright axis. A mechanism as claimed in any of the preceding claims, wherein each said side frame (60, 62) is generally planar and has a length of at least about half of the length of its associated lower link (56, 58). A mechanism as claimed in any of the preceding claims, wherein each of said first and second lower links (56, 58) is upwardly convex along its length. A mechanism as claimed in any of the preceding claims, wherein each of said first and second lower links (56, 58) is integral with its associated side frame (60, 62). A mechanism as claimed in any of the preceding claims, wherein said unitary front link (42) and said unitary rear link (44) are of the same length, and wherein said rearward pivot mount is closer to said support member (30) than is said forward pivot mount. A mechanism as claimed in any of the preceding claims, wherein said first and second lower links (56, 58) are shorter than said spreader frame (26), and wherein a resilient bumper is positioned to cushion contact between the lower end of said unitary rear link (44) and said support member (30). A mechanism as claimed in any of the preceding claims, wherein at least one of said unitary front link (42), said unitary rear link (44) and said side frames (60, 62) is of welded steel fabrication. A mechanism as claimed in any of the preceding claims, wherein at least one of said unitary front link (42), said unitary rear link (44) and said side frames (60, 62) includes a decorative panel detachably connected thereto. A chair including a rocking and gliding mechanism as claimed in any of the preceding claims.

Inventors: BELLEFLEUR PIERRE, DESNOYERS CHARLES, BELLEFLEUR, PIERRE, DESNOYERS, CHARLES
Applicants: DUTAILIER INTERNAT INC, DUTAILIER INTERNATIONAL INC.
Application year: 1999
Main classification: A47C3
IPC codes: A47C3, A47D13