Abstract:
A teething device is provided which includes a fluid-filled membrane sized to be at least partially received in the mouth of a child, a housing attached to the fluid-filled membrane, a handle sized to be grasped by a child, a vibrator configured to impart vibration to the fluid-filled membrane and a pressure switch selectively connecting the vibrator to a power source when a threshold pressure is applied to an outer surface of the membrane.

Description:
TECHNICAL FIELD 
     The invention provides a teether for massaging the gums of a teething child and includes a fluid-filled membrane having a resilient biting surface. Vibration is imparted to the teether through the membrane to provide further stimulation to the gums of the child. This damped mechanical vibration provided through the membrane and to the biting surface along the outer surface of the membrane stimulates and massages the gums of the child. 
     BACKGROUND 
     Teething is the sequential appearance of baby teeth. Generally speaking, teething begins around age six months, and continues until the baby is about three years old. But in some healthy babies, the first tooth appears in the third month; in others, it doesn&#39;t emerge until the infant is a full year old. As a child begins teething, providing a soft article to chew on may provide some relief from discomfort, hasten the eruption of the teeth from the gumline and provide a distraction from the general discomfort associated with the teething process. 
     SUMMARY 
     The invention provides a teether for massaging the gums of a teething child and includes a fluid-filled membrane having a resilient biting surface. Vibration is imparted to the teether through the membrane to provide further stimulation to the gums of the child. This damped mechanical vibration provided through the membrane and to the biting surface along the outer surface of the membrane stimulates and massages the gums of the child. 
     In general, in one aspect the invention provides a teething device which includes a fluid-filled membrane that is sized to at least partially fit in the mouth of a child. A housing is attached to the fluid-filled membrane and includes a handle sized to be grasped by a child. Within the housing, a vibrator is configured to impart vibration to the fluid-filled membrane and a pressure switch selectively connects the vibrator to a power source. The fluid-filled membrane can contain a pliable gel, sterilized water or other suitable fluid medium. 
     Implementation of this aspect of the invention may include one or more of the following features in various embodiments. The vibrator can include an eccentric weight rotably attached to the motor and disposed within the housing. The pressure switch can be coupled to the fluid-filled membrane and configured to activate the motor when a threshold pressure is applied to an outer surface of the fluid-filled membrane. 
     In one embodiment, the pressure switch includes two substantially parallel strips attached together at a first end and disposed in close proximity to each other at a second end, such that when the threshold pressure is applied to the outer surface of the fluid-filled membrane, the parallel strips at the second end contact each other and activate the motor. In another embodiment, the membrane further includes a protrusion near the second ends of the switch which preferentially deflects outward to contact second ends of the switch when the threshold pressure is applied to the membrane. The pressure switch can be adapted to respond to gum pressure on the outer surface of the membrane. The switch may also be adapted to respond to fluid pressure within the membrane. 
     In one embodiment, the motor cycles for a predetermined duration when activated by the pressure switch. In another embodiment, the teething device includes a programmed circuit connected to the pressure switch for producing a sound to complement the vibratory movement when the threshold pressure is applied. In a further embodiment, the outer surface of the membrane device includes teething tabs. In other embodiments, the teether includes a rattle. 
     In another aspect, the invention provides a method of messaging the gums of a child including the steps of placing the fluid-filled membrane of a teether described in the first aspect of the invention close to a child&#39;s mouth, placing the handle proximate to a child&#39;s hand, and imparting vibratory motion to the membrane when the threshold pressure is applied to the outer surface of the membrane. 
     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of an assembled teether, according to the invention. 
         FIG. 2  is a perspective view of the teether shown in  FIG. 1  with one section of the housing removed to show component detail. 
         FIG. 3  is an exploded perspective view of the teether shown in FIG  1 . 
         FIGS. 4A to 4C  are detailed views of the pressure switch and surrounding components in the embodiment of  FIG. 1 . 
     
    
    
     Like reference symbols in the various drawings indicate like elements. Other features and advantages of the invention will be apparent from the description of preferred embodiments thereof, taken together with the drawings, and from the claims. 
     DETAILED DESCRIPTION 
     As shown in  FIG. 1 , a vibrating teether  10  includes a fluid-filled membrane  15 , a housing  20  and a handle  25 . The membrane  15  is dimensioned to fit at least partially within the mouth of a child while the handle  25  is dimensioned and configured to fit the hand of a child. The housing  20  may include, for example, a rattle. The handle  25  may further include looped structures to allow relatively unrestricted movement of the infant&#39;s fingers while grasping the teether  10 . The membrane  15  provides a teething surface and may include a plurality of protuberances  27  arranged about the outer surface to further stimulate the gums of the teething child. 
     As shown in  FIGS. 2 and 3 , and in one embodiment, the housing  20  comprises two halves  20   a ,  20   b  joined (only housing half  20   a  is shown in  FIG. 2  and only half  20   b  is shown in  FIG. 3 ) together to store a power source  30 , a motor  33  and a vibrator  35  disposed within the cavity formed between the housing halves  20   a ,  20   b . The motor  33  is rotably connected to the vibrator  35 . The vibrator  35  may include, for example, an eccentric weight and a rotor attached to the motor  33  which rotates the weight. Rotation of the shaft by motor  33  causes an oscillation of the weight and vibratory movement of the teether  10 . A power source cover  36  ( FIG. 3 ) secures the power source  30  to the housing  20  and a bracket  37  secures the motor  33  along with the vibrator  35  to the housing  20 . A protrusion  38  on the membrane  15  and a protrusion  39  on the handle  25  are each engaged between the housing halves  20   a ,  20   b  to affixed each firmly to the edges of the housing  20 . The power source  30  and the motor  33  are selectively connected by a pressure switch  40 . 
     In one embodiment, the housing  20  and handle  25  may be decoratively shaped and configured for aesthetic purposes. For example, the teether  10  can include one or more decorative elements  41  ( FIG. 3 ) secured to an outside surface of the housing  20 . 
     As shown in  FIGS. 4A to 4C , and in one embodiment, the pressure switch  40  comprises two substantially flexible and generally parallel strips  43   a ,  43   b  made from an electrically conductive material and separated from each other at a first end by a spacer  45  and located proximate each other and separated by a control gap  47  at a second end. The pressure switch  40  is positioned within the housing  20  and adjacent the membrane  15  such that the gap  47  at the second end of the of the pressure switch  40  is proximate to a protrusion  50  extending from an outer surface of the membrane  15 . In other embodiments, the second end of the pressure switch  40  is coupled to the membrane  15 . 
     In one embodiment, the handle  25  is formed of injection molded polypropylene and thermoplastic elastomer (TPE) overmold. The wall of the membrane  15  is preferably between about 0.08 and 0.10 inches and may be formed by any resilient material suitable for teething devices which may include, for example, a TPE. The membrane  15  may contain sterilized water, a pliable gel or other suitable fluid medium, such that it is easily deformable to gum pressure applied to the outer surface of the membrane  15 . 
     In operation, when a threshold pressure is exerted on an outer surface of the membrane  15 , the fluid pressure within the membrane increases sufficiently to deflect the protrusion  50  outward to close the control gap  47  at the second end of the pressure switch  40 . In one embodiment, the threshold pressure is between about  1  and  6  pounds and more preferably between about 2 and 4 pounds. The exertion of the threshold pressure on the membrane  15  closes the pressure switch  40  thereby activating the motor  33  and the vibrator  35 . In one embodiment, the teether  10  includes a programmed circuit (not shown) to operate the motor  33  for a predetermined cycle time for each activation of the pressure switch  40 . In a further embodiment the teether  10  contains a programmed sound circuit and speaker (not shown) disposed within the housing  20  selectively connected to the power source  30  by the pressure switch  40 . Closing the pressure switch  40  activates the programmed sound circuit to produce a pleasing sound to amuse the teething child. 
     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the housing  20  and handle  25  may be of single unitary construction. Accordingly, other embodiments are within the scope of the following claims.