Abstract:
Sleeping compartment support assemblies and methods of driving the same are disclosed to selectively provide reciprocating motion to a sleeping enclosure. An example sleeping compartment support has a drive mechanism that utilizes a rotary motor and a slider crank assembly to generate substantially planar motion in a generally horizontal plane.

Description:
FIELD OF THE DISCLOSURE 
   This disclosure relates generally to childcare products and, more particularly, to self rocking sleeping compartment assemblies and methods of driving the same. 
   BACKGROUND 
   It is common for infants to rest or sleep in a sleeping compartment, such as a bassinet, cradle or crib. Typically, the sleeping compartment is fixedly mounted and is intended to a support to remain stationary. However, some sleeping compartments are designed to move while holding an infant during rest, so as to sooth the child. 
   Some movable sleeping compartments are supported on assemblies that permit a person to push the sleeping compartment to rock the device back-and-forth. Others include a motor to propel the assembly in a swinging or rocking motion. Many prior sleeping compartments, such as bassinets, are constructed to rest on a floor surface and to be located adjacent the floor. Low positioning of sleeping compartments can be inconvenient for a person caring for an infant and may lead to back strain due to the bending and lifting required when placing a child into or removing a child from such sleeping compartments. 
   Automated rocking assemblies typically utilize a spring to capture some of the kinetic energy while damping the end of an upward stroke of the sleeping compartment and then to return the energy on a downward stroke, and/or they have a motor with a relatively large torque rating, due to the lifting involved in the vertical displacement of the mass (e.g., the sleeping compartment and the infant). However, the large, arcuate motions produced by these prior rocking assemblies are not well suited for gentle, reciprocating propulsion of a sleeping compartment, such as a bassinet. 
   Some sleeping compartments are designed with a relatively smaller range of motion and are propelled by a motor. These units typically use a series of solenoids or a motor capable of generating relatively high torque at a low speed, as well as resilient members, such as springs, to dampen movements at the end of each stroke of the device. Unfortunately, such components add significant cost and commonly require an AC power source to supply their power requirements. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an example sleeping compartment support constructed in accordance with the teachings of the invention, shown with an example bassinet assembly. 
       FIG. 2  is an exploded perspective view of the example sleeping compartment support shown in  FIG. 1 , shown with a the frame of the bassinet of  FIG. 1  exposed. 
       FIG. 3  is a perspective view of an example drive mechanism for the example sleeping compartment support shown in  FIG. 1 , shown with a central cover removed. 
       FIG. 4  is a perspective view of the example drive mechanism shown in  FIG. 3 , with a yoke plate lifted away to expose a drive roller. 
       FIG. 5  is a perspective view of an example drive train for the drive mechanism shown in  FIG. 3 , with the yoke plate shown in phantom. 
       FIG. 6  is an exploded perspective view of the example drive mechanism shown in  FIG. 3 . 
   

   DETAILED DESCRIPTION 
   Referring now to the drawings,  FIGS. 1-6  show an example self rocking sleeping compartment assembly  10  that includes a sleeping enclosure  12  connected to a sleeping compartment support  100 . In this illustrated example, as best seen in  FIGS. 1 and 2 , the sleeping enclosure  12  is shown as a bassinet having an elongated compartment  14 , but other types and/or shapes of sleeping enclosure  12  would likewise be appropriate. 
   The bassinet  12  of the illustrated example is formed with an oval frame  16 , a bottom panel  18 , and a fabric enclosure  20 . The underside of the bottom panel  18  is equipped with connectors  22  to removably engage the sleeping compartment support  100 . The fabric enclosure  20  wraps over the frame  16 , presenting a padded upstanding inner wall  24  and a decorative outer skirt  26 . The example bassinet  12  of  FIG. 1  also is shown with a canopy  30  having an adjustable, pivotal canopy stay  32 . An optional lower basket  40  is shown for convenient additional storage, or for temporary use as a stationary removable sleeping compartment. 
   The sleeping compartment support  100  of the illustrated example is constructed and dimensioned to hold, and when desired, automatically move the sleeping compartment  12  in a side-to-side reciprocating or rocking motion. The support  100  has a stationary base  102  having a pair of base portions  104  to rest upon a ground surface. The sleeping enclosure  12  is suspended by the sleeping compartment support  100  at a convenient height from the ground, such as with the bottom panel  18  located approximately 30 inches above a ground surface, to avoid unnecessary bending and straining when lifting a child. The base portions  104  are connected to each other via a pair of lower bars  106 . To provide adjustability for uneven ground surfaces, it will be appreciated that each base portion  104  may incorporate downward extending, height-adjustable feet (not shown). 
   The example base  102  of  FIG. 1  also includes a pair of upward extending posts  108 , each of which is slid downward into a respective base portion  104  and connected thereto with fasteners. The upward extending posts  108  of the illustrated example are connected to each other via an upper bar  110 . The upper bar  110  enhances the stability of the posts  108 . In the illustrated example, a mounting bracket  112  is connected to the upper bar  110  at a position located approximately mid-way between the posts  108 . In the example shown in  FIGS. 1-2 , the mounting bracket  112  is used to connect a drive unit  114  to the upper bar  110 . It will be appreciated that the base portions  104  may be formed of any type of material (e.g., molded plastic, stamped sheet metal or the like). Also, the lower bars  106 , posts  108 , and upper bar  110  may be formed from any type of material (e.g., solid or tubular plastic, metal, or the like). The connections between the various components of the base  102  may be made using mechanical or chemical fasteners, by welding, or by any other suitable connection means. 
   Movably connected to the stationary base  102  of the example sleeping compartment support  100  is an example carrier assembly  116 . The example carrier assembly  116  of  FIG. 2  includes two hub assemblies  118 , each of which is slid over the upper end of a respective post  108  and connected thereto with fasteners. Each hub assembly  118  of the illustrated example includes an upper housing  120  comprising an inner cover  122  connected to an outer cover  124 , a lower housing  130  having an inner cover  132  connected to an outer cover  134 , and first and second links  140 ,  142  pivotally connected at axes  126  to the upper housing  120  and pivotally connected at axes  128  to the lower housing  130 . Each inner cover  132  of a lower housing  130  further includes a pair of mounting recesses  138 . The carrier assembly  116  further includes a pair of control bars  150  the opposite ends of which are received by and connected to the respective mounting recesses  138  in the inner covers  132  of the opposed lower housings  130 . The two control bars  150  of the example carrier assembly  116  of  FIG. 2  also are connected to each other by a bracket  152 . The bracket  152  provides a means for connecting to a drive mechanism. 
   In the illustrated example, the hub assemblies are mirror images of one another. Thus, for ease of discussion, the following description will refer to one hub assembly  118 , but the reader will understand that the description of one hub assembly  118  is likewise applicable to the second hub assembly  118 . The axes  126  at the upper ends of the links  140 ,  142  of the hub assembly  118  are closer together than the axes  128  at the lower ends of the links  140 ,  142 . The pivotal connection of the first and second links  140 ,  142  to the upper housing  120  and the lower housing  130  within each hub assembly  118  provides a four bar linkage or trapezoidal structure that permits a reciprocating or oscillating back-and-forth motion that simulates an arc of a very large radius. The trapezoidal alignment of the upper pair of axes  126  and lower pair of axes  128  causes the movement that simulates an arc of very large radius, and together with gravity, tends to impart a lowest point of travel or self-centering feature of the carrier assembly  116 . It also permits a relatively large amount of horizontal translation with very little vertical displacement throughout the reciprocating motion of the carrier assembly  116 . The small vertical displacement of the mass of the loaded sleeping compartment  12  avoids the need for significant power to lift the bassinet and, thus, permits use of a direct drive reciprocating motion. 
   The direct drive mechanism of the illustrated example pushes and pulls the bassinet  12  via the control bars  150  of the carrier assembly  116 . This pushing and pulling is accomplished by locating the drive unit  114  beneath the bassinet  12  and connecting a drive unit link  154  to the bracket  152  between the control bars  150  of the carrier assembly  116 . The drive unit  114  of the illustrated example has a housing  160  that is connected atop the upper bar  110  via the bracket  112 . This relatively central connection of the drive unit  114  to the carrier assembly  116  helps prevent undesirable twisting of the carrier assembly  116  of the sleeping compartment support  100  as a result of, for example, a torquing force that would be applied by a non-centrally located drive mechanism. 
   Turning to  FIGS. 3-6 , in the illustrated example, the housing  160  opens upward and is enclosed by a first cover  162  that covers a battery compartment  164  (batteries not shown), and by a second cover  166  that covers a drive train  168 . As best seen in  FIG. 3 , with the second cover  166  removed from the drive unit  114 , a yoke plate  170  is exposed. The yoke plate  170  is dimensioned to slide back-and-forth within a track  172  of an upper housing portion  174 . The upper side of yoke plate  170  has two upstanding flanges  176 . As seen in  FIG. 2 , the flanges  176  extend through the second cover  166  and are pivotally connected to a drive unit link  154 . The drive unit link  154  may be connected to the bracket  152  to thereby provide a reciprocating direct drive connection between the drive unit  114  and the control bars  150 , and, thus, the bassinet  112 . 
   In  FIG. 4 , the example yoke plate  170  has been lifted from the drive unit  114 , exposing a track  180  on the underside of the yoke plate  170 . The track  180  of the illustrated example yoke plate  170  has an axis that is perpendicular to an axis of the track  172  in which the yoke plate  170  slides. A disk portion  182  that is rotatably connected to a drive shaft  184  also is exposed in  FIG. 4 . A roller  186  is rotatably connected to the disk portion  182  on an axle  188  that is spaced from the drive shaft  184 . The roller  186  is dimensioned to fit within the track  180  on the underside of yoke plate  170  so as to form a double slider crank or Scotch yoke drive mechanism. By this drive mechanism, it will be appreciated that the rotary motion of the drive shaft  184  is transmitted through the disk portion  182  to the roller  186 . The offset of the axle  188  from drive shaft  184  provides an eccentric path for the roller  186  which rolls within the track  180  on the underside of the yoke plate  170  along a first axis which is perpendicular to the axis of sliding travel of the yoke plate  170  within the track  172 . The eccentric path of the roller  186  thereby causes the yoke plate  170  to be driven back-and-forth in a sliding motion in the track  172  as the disk portion  182  rotates. 
   In the illustrated example as shown in  FIGS. 5 and 6 , the drive train  168  of the drive unit  114  includes significant gear reduction. The illustrated example drive train  168  uses both gears and drive belts for noise reduction. A small, battery operated motor  190  is connected to, and selectively rotates, a small diameter initial drive pulley  192 . A first elastomeric drive belt  194  connects the initial drive pulley  192  to a first relatively larger input pulley of a secondary drive pulley assembly  196  to thereby transmit a drive force and provide a first gear reduction. A second, relatively smaller output pulley (not shown), is located beneath the secondary drive pulley assembly  196 . A second elastomeric drive belt  198  connects the second, relatively smaller, output pulley of the secondary drive pulley assembly  196  to a relatively larger input pulley of a tertiary drive pulley assembly  200  to thereby transmit a drive force and a provide a further gear reduction. The tertiary drive pulley assembly  200  also has a relatively smaller output gear (not shown), located beneath the illustrated pulley. The relatively smaller output gear of the tertiary drive pulley assembly  200  engages a first relatively larger input gear of a quarternary drive pinion  202  to thereby transmit a drive force and provide a further gear reduction. The quarternary drive pinion  202  also has a second relatively smaller output gear that engages a first relatively larger input gear of a final drive pinion  204  to thereby transmit a drive force and provide yet a further gear reduction. The drive shaft  184  is connected to the final drive pinion  204  and passes through shields  206  and upper housing portion  174 . The disk portion  182  is connected to the distal end of the drive shaft  184 . The roller  186  is connected to the disk portion  182  such that the drive force is conveyed to the yoke plate  170  as above explained. In the illustrated example, the multi-stage gear reductions provided by the pulley and gear combinations collectively provide an overall gear reduction of approximately 200:1. The relatively high speed, low torque battery operated motor  190  is able to provide sufficiently powerful, direct, reciprocating pushing and pulling drive motion to drive link  154  while it is pivotally connected to the yoke plate  170 . 
   When the sleeping compartment support  100  is assembled, an enclosure, such as in the form of the bassinet  12 , may be placed atop and connected to the carrier assembly  116  by engaging the connectors  22  on the underside of the bottom panel  18 , whereby each connector  22  straddles a control bar  150  of the carrier assembly  116 . The bassinet  12  then may be used in a stationary mode, or if desired, may be rocked automatically by engaging the drive unit  114 . The bracket  152  is configured to permit removable connection of the drive unit  114  via the link  154 . Thus, the drive unit  114  may be connected to the carrier assembly  116  by connecting the link  154  to the bracket  152 . The drive unit  114  may be operated by a remote control unit  210  which is shown in  FIG. 2  as being removably connectable to a side of the bassinet  12 . It will be appreciated that the control unit  210  alternatively may be a handheld remote control unit and/or constructed to connect to another portion of the assembly  10 . Also, the control unit  210  may be linked to the drive unit  114  wirelessly or by conventional wire connections. Additionally, as an alternative, the drive unit  114  may have controls incorporated directly into the drive unit housing  160 , or otherwise conveniently configured. It also will be appreciated by those of ordinary skill in the art that the control unit  210  also may be made to operate the drive unit  114  at more than one selected speed. 
   While the present disclosure shows and demonstrates various example supports  100  and sleeping enclosures  12  that are adapted to provide gentle, substantially planar, reciprocating motion for a sleeping child, these examples are merely illustrative and are not to be considered limiting. It will be apparent to those of ordinary skill in the art that various sleeping compartment supports and/or sleeping enclosures can be constructed without departing from the scope or spirit of the present disclosure. Thus, although certain example methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.