Patent Publication Number: US-2007096522-A1

Title: Locking device for a rocking chair

Description:
FIELD OF THE INVENTION  
      This invention generally relates to the field of movable and lockable furniture, and more specifically concerns a locking device for locking a movable chair such as a rocking chair or rolling armchair.  
     BACKGROUND OF THE INVENTION  
      In the furniture industry, many pieces of furniture exist that include movable parts that rotate, slide, bend and/or swivel with respect o other parts of the furniture. Reclining chairs, rocking chairs and rolling armchairs are examples of such furniture. When producing furniture, mass production techniques are often used to fabricate durable, quality pieces of furniture. When producing a rocking chair, for example, the design of the chair is a major factor in determining not only its viability on the market but also its facility to be mass produced. In this sense, a rocking chair or another kind of mobile furniture containing a locking mechanism for locking the movable parts In place should be designed in order to be robust and easily assembled.  
      Rocking and other mobile chairs often have a locking mechanism incorporated therein. In fact, the locking mechanism is an important and desirable feature in many mobile furniture pieces. A locking mechanism stops the movement of the mobile parts, usually In response to a stimulus from the user. Lockability in moving parts that recline, slide, rock and/or pivot is often required feature.  
      There are many different mechanisms currently used to lock movable parts in fixed positions. However, a robust, quality, and efficiently assembled locking mechanism for locking a rocking chair in various fixed positions along its rocking path is lacking in the prior art.  
      In the prior art, various locking mechanisms exist for locking mobile parts of a chair in place. The U.S. Pat. No. 5,121,966 (TISCHLER) describes an adjustable recliner chair including a locking mechanism. The locking mechanism principally enables the reclinable back of the chair to be locked in various positions. The mechanism has numerous working parts including a cam interconnected to a lever handle via a connecting bar, an arcuate member engaged by the cam and being pivotally attached to the base of the chair. The interaction between the cam and the arcuate member causes the latter, through a pivoting motion, to cause the chair to be locked in a certain reclining position. TISCHLER does not show how to lock a rocking chair and, furthermore, does not show a simple and robust assembly for doing so.  
      The U.S. Pat. No. 6,406,095 B1 (BOUCHARD et al.) describes a self-locking chair. The locking mechanism described therein blocks all movement when an occupant desires to sit up from the chair. An actuator device is situated in the interior of the back, which is stuffed and padded, of the mobile chair and the locking mechanism is situated under the seat or its lateral sides. The locking action is thus actuated by a movement of the back of the chair, reacting to the movement of the upper part of the body of the occupant. The locking mechanism taught by BOUCHARD et al. includes levers, detectors, springs, actuators, force transmitters and a notch plates-all of which are interconnected to give a complicated and potentially costly locking mechanism. Also, in the case of BOUCHARD et al., a tubular metal chair is used and the mechanism requires a padded back to hide part of the mechanism. As soon as an occupant goes forward in the chair, that is, when his back in no longer pushing on the back cushion, the chair stops rocking or reclining. Furthermore, when the actuator to look the chair in place is situated as in BOUCHARD et al., it requires a substantial force to lock the chair, for example, the force of a larger person sitting in the chair.  
      In summary, the prior art teaches various techniques and mechanisms for locking mobile chairs in various positions, but such mechanisms involve numerous disadvantages that could be overcome. There is therefore a need for a locking device alleviating the drawbacks of the prior art.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present Invention provides a locking device for a rocking chair. The rocking chair has a stationary lower frame and an upper frame rockingly connected thereto. The upper frame delimits a horizontal seat area for a user. The locking device includes a notched member mountable to the lower frame and having at least one notch. It also includes a lever assembly operatively connectable to the upper frame. The lever assembly includes a support mountable to the upper frame and a lever arm pivotally mounted to the support. The lever arm has a first end extending in the seat area and being engagable by the user when said user sits in the seat area, and a second end engagable with the at least one notch. The lever assembly also includes biasing means having a first portion resting on the support and a second portion for urging the second end of the lever arm against the notched member to lock the upper and lower frames together when the second end is engaged with one of said at least one notch. The second end disengages the one notch when the user engages the first end to pivot the second end out of said one notch, thereby unlocking the device.  
      The invention also provides a locking device for a rocking chair having a stationary lower frame and an upper frame rockingly connected thereto. The locking device Includes at least one friction band mountable to the lower frame and a bar rotatably mountable to the upper frame about an axis thereof. The axis is substantially transverse with respect to a rocking path of the rocking chair. The device also includes at least one cam eccentrically and fixedly mounted to the bar, having a surface capable of cooperating respectively with said at least one friction band on any location of the rocking path of the upper frame. The device further includes a handle mounted to the bar, and rotatable by a user to thereby rotate the cam via the bar between a first position where the surface of the at least one cam engages with the at least one friction band to lock together the upper and the lower frames in one of said locations of the rocking path, and a second position where the surface of the at least one cam disengages with the at least one friction band to unlock the upper frame from the lower frame.  
      The advantages and operation of the invention will become more apparent upon reading the detailed description and referring to the drawings that relate to preferred embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of the locking device in relation to the lower and upper frames of a rocking chair, according to the present invention.  
       FIG. 2  is a close up perspective view of the locking device in relation to parts of the lower and upper frames of a rocking chair, in a first locked position, according to the present invention.  
       FIG. 3  is a close up perspective view of the elements shown in  FIG. 2 , in a first unlocked position.  
       FIG. 4  is a close up perspective view of the elements of the locking device in a second locked position in relation to parts of the lower and upper frames of a rocking chair, according to the present invention.  
       FIG. 5  is a close up perspective view of the elements shown in  FIG. 4 , in a second unlocked position.  
       FIG. 6  is a perspective view of the locking device disconnected from the frames, according to the present invention.  
       FIG. 7  is a perspective view of a rocking chair in which the locking device, according to the present invention, is preferably used. 
    
    
      While the invention will be described in conjunction with example embodiments, it will be understood that it is not intended to limit the scope of the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included as defined by the appended claims  
     DESCRIPTION OF PREFERRED EMBODIMENTS  
      In the following description, similar features in the drawings have been given same reference numerals.  
      A preferred embodiment of the present invention is shown in  FIG. 1 . The locking device  20  is used to lock a chair, such as a rocking chair, in a variety of positions. The device may also be used to lock rolling armchairs or other similar pieces of mobile lockable furniture. The locking device  20  is preferably used with a rocking chair having a stationary lower frame  22  and a mobile upper frame  24 . As can be appreciated in  FIG. 1 , the lower frame  22  preferably contacts the ground and is stabilized by two leg members. The upper frame  24  preferably includes two vertically oriented pieces respectively pivotally mounted to opposite sides of the lower frame  22  and fixedly interconnected with a rod  23 , which is preferably made of metal. The upper frame  24  is rockingly connected to the lower frame  22 . By “rockingly connected” it is meant that the connection enables the upper frame  24  to be mobile relative to the lower frame in a rocking and/or pivoting manner. This is achieved by using connection means known in the art. In  FIG. 2 , the connection means are shown to be two pivot points  25 A,  25 B. Other connection means may include bearings, rollers, curved members and/or pivoting or swinging means. Depending on the connection means a variety of rocking paths such as elliptical, arced, variable, etc.) may be enabled. Furthermore, the upper frame  24  preferably delimits a horizontal seat area for a user to sit in. The upper and lower frames  22 ,  24  are advantageously made of wood, but can also be made of other materials known to a skilled workman.  
      The locking device  20  further comprises a notched member  26  mounted to the lower frame  22 . The notched member  26  has at least one notch  28  and preferably a plurality of notches  28 . As can be seen in  FIG. 2 , the notched member  26  is preferably plate-shaped having a plurality of notches  28  machined therein and is fixed on the inside of the lower frame  22  so that the notches  28  face upward to be engaged. However, the notched member  26  may take a variety of forms and may be mounted anywhere and oriented anyhow on the lower frame  22  to be engagable. The notches  28  may also be angled or have particular shapes to ensure that the rocking motion is stopped when the device is locked.  
      The locking device  20  further includes a lever assembly  30  operatively connected to the upper frame  24 . The lever assembly  30  includes a support  32  mounted to the upper frame  24 . The support  32  preferably takes the form of a bar, as shown in  FIG. 2 . The support  32  may be rotationally or fixedly mounted to the upper frame  24 . The lever assembly  30  also includes a lever arm  34  pivotally mounted to the support  32  and having a first end  36  and a second end  38 . The first end  36  extends in the seat area and is engagable by the user. Preferably, the first end  36  also includes a push plate  40  having a surface that is horizontal and comfortably engagable by the user. The length, shape and orientation of the first end  36  may be modified depending on the operating conditions and the expected weights to be involved. The second end  38  of the lever arm  34  is engagable with any of the notches  28  of the notched member  26 . As seen in  FIG. 2 , the lever arm  34  is preferably L-shaped, the second end  38  extending laterally away from the first end  36  to engage a notch  28 . The second end  38  extending laterally away is preferably pivotally connected to the support  32  by means of an additional pivot arm  39 , which helps to stabilize the second end  38  in its pivoting motion preferably. Furthermore, the lever arm  34  preferably includes a pivotal fastener  42  provided between the first and second ends  36 ,  38  pivotally connected to the bar  32  to enable the lever arm to pivot thereabout. The pivotal fastener  42  preferably takes the form of a cylinder through which the bar  32  passes.  
      The lever assembly  30  further includes biasing means  44  to urge the lever arm  34  into the locked position. More specifically, the biasing means  44  have a first portion  46  resting on the support  32  and a second portion  48  for urging the second end  38  of the lever arm  34  against the notched member  26  to lock the upper and lower frames  24 ,  22  together when the second end  38  is engaged in one of the notches  28 .  
       FIG. 2  shows the second end  38  engaging a notch  28  and thus locking the device. Referring now to  FIG. 3 , the first end  36  of the lever arm  34  is engaged by the user, which pivots the second end  38  out of the notch  28  and thereby unlocks the device  20 . Preferably, the second end  38  is a horizontal bar-shaped element that is displaced up and down to unlock and lock the device.  
      Returning to  FIG. 2 , the biasing means  44  are preferably preloaded when the device is in a locked position and are additionally loaded when, as in  FIG. 3 , the second end  38  disengages the notch  28 . The biasing means  44  preferably include a third portion  50  extending away from the first portion  46  and resting on the upper frame  24 , advantageously an the rod  23  interconnecting the two parts of the upper frame  24 . The third portion  50  of the biasing means  44  helps to stabilize and preload the latter. As can be seen in  FIGS. 2 and 3 , the biasing means preferably take the form of a spring, and still preferably a torsion spring that is U-shaped. Thus, the first end  46  is a coil through which the bar  32  is passed and which enables the springing force of the spring  44 . The coil  46  may have any number of windings according to the desired springing ability of the spring  44 . The second and third portions  48 ,  50  define the two open ends of the U-shaped spring  44  and are provided with hooks for resting on the lever arm&#39;s second end  38  and the rod  23 , respectively. When the second and third ends  48 ,  50  are brought together, the tension in the spring  44  is increased.  
      The biasing means  44  may also take the form of other kinds of springs, pistons and/or urging mechanisms or actuators, and may be arranged on the rocking chair assembly so as to urge the second end  38  of the lever arm  34  toward the notched member  26 . The biasing means  44  are preferably mounted to the support  32  but could also be operatively mounted to the upper frame  24  and the second end  38  for urging the latter. The first portion  46  (coil) of the spring  44  is preferably mounted to the support  44  to stabilize the spring  44  and to keep the latter tightly in place while enabling the biasing effect.  
      Referring back to  FIG. 1 , the lever assembly  30  further includes a ring member  52  retainingly connecting the upper frame  24  and the second end  38  of the lever arm  34 . The ring member  52  contains an orifice  54  through which the rod  23  of the upper frame  24  as well and the second end  38  are passed. By “retainingly connecting” it is meant that the ring member  52  delimits a maximum distance that the rod  23  and second end  38  can be from each other. Accordingly, the biasing means  44  are preloaded at any point on the rocking path. For example, if the upper frame  24  is rocked so that the second end  38  cannot, when urged, engage the notched member  26  because it is out of a lockable range, the second end  38  will only be urged until the maximum distance from the rod  23 , as defined by the ring member  52 , is obtained,  
      According to a preferable construction, the rod  23 , the second laterally extending end  38  of the lever arm  34  and the support  32  (bar), are parallel with each other, and still preferably, are horizontal and perpendicular with respect to the rocking path of the upper frame  24 .  
      As a variant to the locking device  20  described hereabove, the variant shown in  FIGS. 4 and 5 , the support  32  is rotatably mounted to the upper frame  24 .  
      Furthermore, the locking device further includes at least one friction band  70  mounted to the lower frame  22 . Preferably, the friction band  70  is fixed to the lower frame  22 , and is oriented upward to be engagable. They are preferably made of a rubber material. Also, the friction band  70  is advantageously curved according to the rocking path of the upper frame  24  so that is may be engaged at any point of the rocking path. The locking device  20  further includes at lest one cam  72  eccentrically and fixedly mounted to the support bar  32 . Preferably, as shown in  FIG. 1 , there are provided two friction bands  70  and two corresponding cams  72  for engaging the former. The cams  72  are provided with a surface capable of cooperating with the respective friction bands  70  on any location of the rocking path of the upper frame  24 . Thus, the cam  72  may engage the friction band  70  at an infinite of individual locking positions to lock the upper frame  24  at any point. This variant thus provides continuous locking ability as opposed to the discrete locking ability of the preferred embodiment. Preferably, the cam  72  rotates and engages the friction band  70  from above, pushing downward thereon. A handle  74  is also provided, being mounted to the support bar  32  and being rotatable between a first position (as in  FIG. 4 ) where the surface of the cam  72  engages with the friction band  70  to lock together the upper and lower frames  24 ,  22 , and a second position (as in  FIG. 5 ) where the surface of the cam  72  disengages with the friction band  70  to unlock the upper frame  24  from the lower frame  22 .  
      Referring to  FIGS. 4 and 5 , the cam  72  is advantageously provided with a covering guard  76  covering the cam  72  and operatively connected to the upper frame  24 . The covering guard  76  is preferably rotationally slidable on the cam  72  and defines the surface for cooperating with the corresponding friction band  70 . The covering guard  76  is also preferably translationally slidable with the upper frame along a guided path. As shown in  FIG. 4 , the covering guard  76  further includes a guide member  78  extending away from the cam  72  and having a guide slot  80  provided therein. The guide member  78  guides the covering guard  76  when the latter engages the friction band  72  and is pinched thereagainst by the rotating cam  72 . Preferably, the rod  23  is passed through the guide slot  80  and slides therein when the cam  72  is rotated. In  FIG. 4 , the rod  23  is shown to be at the extremity of the guide slot  80  before the handle is rotated, while in  FIG. 5  the rod is shown to have moved within the guide slot  80 .  
      The handle  74  is preferably curved and is of a length and shape suitable for a user to rotate by applying the necessary force known to a skilled workman. It should be noted that the handle is easily accessible for the user, while the rest of the locking mechanism is preferably hidden underneath the seat area of the mobile or rocking chair.  
      Referring back to  FIG. 4 , the device  20  further includes a biasing unit  82  connected to the upper frame  24  and the cam  72 . This unit  82  is used primarily to vary the resistance to rotating the cam  72  with the handle  74 . The biasing unit  82  is preferably preloaded when the cam  72  is disengaged from the friction band  70 . The biasing unit is preferably mounted to the greater portion of the eccentrically mounted cam  72  and thus, when the said greater portion of the cam  72  rotates to engage the friction band  70  away from the opposite end of the biasing unit  82 , the biasing unit resists the rotation. The response of the biasing unit  82  can be seen in  FIG. 5 , where the unit  82  is additionally stretched.  
      As can be seen in  FIG. 6 , the locking device can be arranged so that the second end  38  of the lever arm  34  extends to the right or to the left. Furthermore, the handle, shown in  FIG. 1 , can be on the right or left side of the rocking chair.  
      The components shown in  FIG. 6  are preferably made of metal such as stainless steel, but could also be constructed using reinforced polymers, plastics, or wood.  
      As shown in  FIG. 7 , the chair with which the locking device according to the present invention is used is preferably a rocking chair. The preferable type of rocking chair to be used with the current invention is a glider rocker that moves frontward and backward while having upward and downward movements as well. The locking device is mounted underneath the seat area of the chair so that a person engages and unlocks it when they sit. An advantage of the present invention is that children of about six or eight years old can apply the necessary force to automatically unlock the locking device when they sit on the rocking chair. The device unlocks with an applied force of about 35 lbs, which is quite advantageous.  
      Although preferred embodiments of the present invention have been described in detail herein and illustrated in the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments and that various changes and modifications may be effected therein without departing from the scope or spirit of the present invention.