Abstract:
An automatic bassinet rocking device imparts a rocking motion to a bassinet or rocking crib. A housing is supported above the rocker base of the bassinet on adjustable legs so that the device straddles the curved rocking base. A reciprocating rod descends from the housing and attaches to a strap or clamp at an anchor point on the rocker base. An oscillatory drive inside the housing imparts a reciprocating motion via the reciprocating rod onto the rocker base.

Description:
BACKGROUND OF THE INVENTION 
     This invention is related to reciprocation motion devices that may be used to impart rocking motion to furniture, and is more particularly concerned with a device that may attach to a rocking cradle or bassinet to provide a gentle, soothing rocking motion. In particular, this invention is directed to a bassinet rocking device that easily installs onto the rocker bar or base of the bassinet, and creates the desired rocking motion without creep or travel, i.e., without the device causing the bassinet to walk across the floor. 
     Conventional rocking devices that may be used in connection with a cradle, or in some cases with a rocking chair or other furniture, typically clamp onto the base of the cradle or other item, and typically have a bar or arm or leg that moves up and down and pushes against the floor to create a rocking or “see-saw” motion. Because the reciprocating arm is moving against the floor, the device can produce a forward force, or sometimes a transverse force, that tends to move the cradle gradually across the floor. 
     Some alternative arrangements are employed with cradles that are suspended in a frame and do not employ the conventional (curved) rocker bars at the base. The rocking device typically is built in or has to be permanently installed in a retrofit fashion. 
     There is a need for an automatic, self-rocking bassinet device, sold and maintained as a separate unit, and which can be easily coupled to any existing bassinet or cradle of the type that has curved rocker bars or bases from which the main support legs rise to the body of the cradle or bassinet. The device should also be configured so it can be coupled to a child&#39;s rocking chair for automatically providing a sustained, gentle rocking motion to that item of furniture. 
     In addition, not one has previously provided a compact, affordable self-contained attachable unit that can be employed with all or most types of bassinet or cradle, and can provide a sustained, gentle and soothing rocking motion to satisfy the infant&#39;s comfort needs. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     Accordingly, it is an object to provide an auto-rocking bassinet device that can be attached or coupled to an existing bassinet or cradle, and which overcomes the drawbacks of the devices of the prior art. 
     Another aspect of this invention is to provide a bassinet rocking device that stands on the floor of the room where the bassinet is located, with a main body or housing disposed over the rocker base of the unit, and with a reciprocating arm that descends from the housing and releasably clamps or connects to an anchor point on the rocker bar to gently pull the bar up and release it down, in a manner that imparts the desired rocking motion to the bassinet without causing the bassinet to walk or travel across the floor. 
     The unit can be battery powered, with a DC motor and a worm-gear drive within the housing to operate a crank that imparts an oscillatory motion to the reciprocating arm. The battery power can be provided from standard batteries within the housing or from an available DC power supply. Low voltage operation is desired for safety reasons. Alternatively, a spring motor can be used, wound up to provide rocking motion for at least several minutes. 
     According to an aspect of this invention, a bassinet rocking device is provided that connects removably with a bassinet. The bassinet should have a rocker base, of a gently curved shape, that is supported on a floor. The legs of the bassinet rise from the rocker base and support the bassinet above the rocker base. The rocker base provides an anchor point, preferably near one of the legs, that is capable of at least limited up-and-down motion to impart a gentle rocking oscillatory motion to the bassinet. 
     The bassinet rocking device has a main body, i.e., a housing, with support legs that rests on the floor and support the housing at a position just above the rocker base. A strap, clamp or other equivalent coupling device removably attaches onto the anchor point on said rocker base, and a reciprocating arm connects to this coupling. The reciprocating arm has an upper end situated within the housing and has a lower portion that descends from the housing so that its lower end attaches to coupling device. The arm may be rigid or flexible. 
     A drive mechanism within the housing has an oscillatory portion, e.g., a wheel or crank, attached to the upper end of the reciprocating arm. This imparts a repetitive oscillatory motion onto the arm, which in turn moves the rocker base up and down to create the desired rocking motion. 
     In a favorable embodiment, the housing of the unit has a U-shaped recess at one end, and the recess is dimensioned to fit around one of the legs that rises from said rocker base. This allows the support legs that are positioned at each corner of the device, so that the forces of weight and rocking are directed downward and are distributed more or less evenly among the support legs, for stability. In the preferred embodiment, the support legs each includes a height adjustment mechanism to permit the height of the housing above the floor to be adjusted to an optimal height for the associated bassinet. Also, the support legs may each include a foot portion at a lower end thereof, with a resilient non-slip pad at its lower surface in contact with the floor. 
     Favorably, the coupling device can be in the form of a flexible strap of a sturdy woven material, and adapted to wrap around the rocker base at the anchor point. The strap may have a hook-and-loop material (e.g., Velcro) attached to it on its side facing the anchor point of the rocker base. A patch or portion of a mating hook-and-loop (e.g., Velcro) material can be attached to at the anchor point onto the rocker base. 
     The reciprocating arm can be a rigid rod and can include a mechanism to permit adjustment of its length. 
     The drive mechanism may include an electric motor within the housing, with means providing battery electric power to the electric motor, and a control circuit for controlling speed of the electric motor. There may also be a mechanism for controlling the throw or stroke length of the reciprocating motion. In one preferred mode, the oscillatory portion of the drive mechanism can be in the form of a worm gear arrangement, having a screw worm driven by the motor, a worm gear meshing with the screw worm, and a crank device driven by the worm gear. The upper end of the reciprocating arm is then coupled to the crank device. 
     These and other objects, features, and advantages of the invention will become apparent from the following detailed description of a selected preferred embodiment, which is to be read in connection with the accompanying Drawing: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a perspective view of a bassinet or rocking cradle, shown with an associated rocking device according to one exemplary preferred embodiment of the present invention. 
         FIG. 2  is a enlarged elevational view thereof. 
         FIG. 3  is a schematic view of the motor and oscillatory mechanism thereof. 
         FIG. 4  is a perspective view of an alternative embodiment. 
         FIG. 5  is a top view thereof taken at line  5 - 5  of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the Drawing Figures, and initially to  FIG. 1  and  FIG. 2 , a cradle or bassinet  10 , in general terms, has a main body  12  for holding the infant, and has a pair of curved rockers or rocker bases  14 . There are legs  16  that are affixed into the bases  14 , and these rise up from the rocker bases to support the body  12 . The curved lower side of each rocker base  14  has a curvature radius that allows at least a limited amount of rocking motion. Here, the bases are disposed transversely, so the rocking is along the longitudinal or roll axis, but in other versions the rockers can be disposed along the fore-and-aft direction, so that rocking occurs on the transverse or pitch axis. 
     An automatic rocking device  20  according to this invention is shown attached to one of the rocker bases  14  at an anchor point that is at or near one of the bassinet legs  16 . The rocking device  20  has a main body or housing  22 , depicted in this embodiment as an elongated generally flat member, and which has four legs  24 , one at each corner, that rest on the floor, straddling the rocker base  14 , to support the housing at a small distance above the rocker base  14 . Each support leg has an inner slide  26  that can be extended out to adjust the length of the support leg  24 . In this example, each leg  24  has an engaging detent  28 , in the form of a spring-loaded button, to hold the leg in the selected elevated position. At the lower end of each leg  24  is a foot member  30 , with a resilient pad  32  of rubber or soft pliable plastic material. The pads  32  contact the floor, and these provide friction to help keep the device  20  in place on the floor. 
     A U-shaped recess  36  is provided at one end of the housing  22 , and permits that end of the housing to extend at least partly around the associated bassinet leg  16 . 
     A reciprocating rod  38  projects downward through an opening in the lower side of the housing  22  and attaches to a clamping device that is affixed onto the anchor point on the rocker base  14 . In this example, the clamping device includes a flexible strap  40  that wraps over the rocker base, and grommets at the end of the strap fit onto a hook at the lower end of the reciprocating rod  38 . In this embodiment, a strip  42  of a hook-loop material, e.g., Velcro is sewn onto the inner or rocker-facing surface of the strap  40 . Favorably, this can be the loop material, and one or more patches  44  of the corresponding hook material can be affixed onto the sides of the rocker base at the anchor point. 
     A motorized reciprocating mechanism  50  contained within the housing  22  of the device imparts a rhythmic up-and-down oscillatory motion onto the reciprocating rod  38 . This mechanism  50  can be implemented as a battery-operated DC motor drive, as illustrated schematically in  FIG. 3 . Here, the reciprocating mechanism includes a DC motor  52 , receiving power from a source  54  of battery power, which is here represented as a battery but could be implemented with an external source of low-voltage electric power. The battery power is supplied to a control circuit  56 , e.g., a speed control, which may have an associated on-off switch  58  and a speed control selector  60 . Here the latter selector  60  is represented schematically as a variable resistance or potentiometer, but in practical implementations this could be a digital control that would change motor speeds incrementally up or down. In  FIG. 1 , the on-off switch  58  and speed control selector  60  are shown implemented as push buttons on the top of the rocking device housing  22 . 
     The shaft of the motor  52  is coupled to a worm drive  62 , namely a worm screw  64  that engages the teeth of an associated worm gear or worm wheel  66 . The worm wheel  66  in turn rotates a crank mechanism  68 , and the upper end of the reciprocating rod  38  is attached onto a crank pin on the crank mechanism. The worm drive  62  serves as a compact and effective transmission for providing low speed oscillatory motion with sufficient torque for the rod  38  to lift and lower the anchor point of the associated rocker base  14 . 
     The reciprocating rod  38  and strap  40  gently pull up on the rocker base to lift is a suitable distance, and then gently lower the rocker base, effecting a gentle, comforting rocking motion that is satisfying to the infant that is placed in the bassinet  10 . 
     The reciprocating rod can be implemented as a two-piece threaded rod, so that its length can be adjusted by twisting its lower end to lengthen or shorten it, as needed. In some embodiments, the throw or stroke of the crank  68  may be adjustable to achieve a desired amount or rocking motion. 
     The rocking device  20  of this invention has its non-moving feet  30  holding steady onto the floor of the room on either side of the rocker bar or rocker base  14 , and the reciprocating mechanism and reciprocating rod  38  simply raise and lower the rocker base at the anchor point. This motion produces far less travel or “walking” of the bassinet or cradle than do the devices of the prior art that push intermittently up and down against the floor, so with this device the bassinet or cradle is much more likely to remain at the same spot. 
     The rocking device can be used with any existing rocking bassinet or cradle, as the device  20  rests on the floor and only connection that needs to be made to the cradle is to attach the patch  44  of Velcro or other hook-and-loop material at the anchor point and to wrap the strap  40  around the rocker base at that point. These patches of hook-and-loop material are typically provided with an adhesive backing, and are quickly installed without difficulty. 
     The battery-operated device, as shown and described, is preferred, but a wind-up spring motor-powered drive could be employed in some cases. 
     An alternative embodiment shown in  FIGS. 4 and 5  is a rocker device having a housing  120  that is integrated into the rocker base  14 . This embodiment employs a rotating arm as in the first embodiment, with the leg fully housed so that the portions of the housing  120  overhang the sides of the rocker base. Various methods may create up and down motion. In this version, adjustable length leg or legs  130 , positioned on one or both sides, have their upper or distal ends attached to a rotary drive  140  within the housing. The leg or legs  130  swing up and lock into place when not needed, and can be moved down for use in rocking the bassinet. A speed knob  158  and timer knob  160  are positioned on the top of the housing. 
     While the present invention has been described with reference to several specific preferred embodiments, it should be understood that the invention is not limited to those precise embodiments. Rather, many modifications and variations would present themselves to persons skilled in the art without departure from the scope and spirit of this invention, as defined in the appended claims.