Self-charging Appliance And Stand

Abstract

A hair clipper is the particular appliance shown. It normally rests horizontally on a stand having plural electrical contacts and internally provided with a transformer and with circuit elements supplementing those within the hair clipper for recharging batteries by which the hair clipper is powered, the charge being reduced to a trickle charge when the batteries are ready for use. The hair clipper and stand have complementary surfaces for guiding the hair clipper to a position in which its contacts are properly engaged with yieldable contacts in the stand. The movable blade of the hair clipper can be adjusted for fineness of cut.

Description

BACKGROUND OF THE INVENTION

In previous constructions mounting a self-charging appliance on a stand, the appliance has been positioned upright where it tends to tilt and also presents an awkward appearance and is more difficult to grasp than a hair clipper in the generally horizontal position herein disclosed. Also self-charging appliances have normally had to be plugged in by connecting a plug and receptacle.

SUMMARY OF THE INVENTION

Invention resides primarily in the cooperative relationship between the appliance and the stand and in the provision of elements of the self-charging circuit between the appliance and the stand, the arrangement being such that the appliance, when not in use, rests in appropriate position to be grasped by the operator and, in that position, is urged by complementary camming surfaces of the stand and appliance to cause engagement of contacts between the appliance and stand to connect the circuit components which are respectively disposed in the appliance and the stand.

No claim is made herein to the self-charging circuit as such, this having been developed by General Electric Company.

The invention also includes the means on the clipper which provides a way for a slide used in adjustment of the comb plate.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a perspective view of a combination appliance and stand assembled in charging position.

FIG. 2 is a view in perspective showing the appliance and stand in mutually separated positions, the appliance being partially turned over to expose the portions thereof which coact with the stand.

FIG. 3 is a view showing the appliance and stand assembled, as in FIG. 1, the stand being shown in longitudinal section and the appliance primarily in side elevation but with parts broken away.

FIG. 4 is an enlarged detail view taken in transverse section on the line 4--4 of FIG. 3.

FIG. 5 is a circuit diagram.

FIG. 6 is a view in perspective of the circuit components and batteries carried by the appliance.

FIG. 7 is a plan view of the hair clipper which exemplifies the appliance, the cover thereof being removed.

FIG. 8 is a view of the hair clipper in longitudinal section on the line 8--8 of FIG. 7.

FIG. 9 is a view in perspective showing in mutually separated positions a fragmental portion of the hair clipper and the guard.

FIG. 10 is a view in perspective of a fitting which provides a way for the slide which positions the guard plate.

DETAILED DESCRIPTION

The stand 10 as shown is specifically designed for the support and recharging of the hair clipper which exemplifies an appliance which may be operated by self-contained batteries recharged when the clipper is placed on the stand. The stand includes a base portion 12 and a complementary cover portion 14 respectively provided with interior cavities 16 and 18. Most of the charging circuit components are in the cavity 16 of base 12. The transformer 20, however, extends upwardly into cavity 18 as best shown in FIG. 3. Fasteners such as bolts 22 hold the parts 12 and 14 together.

The hair clipper 26, which has been selected to exemplify a cordless appliance, has a DC motor 28 anchored by strap 30 and provided with an armature shaft 32 operable in bearings 34 and 36 for which the portion 38 of the hair clipper provides supports at 40 and 42 (FIGS. 7 and 8). An eccentric 44 at the forward end of the armature shaft 32 operates between the arms of a yoke 46 carried by the movable clipper blade 48 to actuate this laterally on the fixed blade or guard plate 50 subject to the bias of spring 52. To control the cut, the fixed blade or guard plate 50 may be moved in and out in a direction longitudinally of the clipper by means of hand lever 54 on rock shaft 56 which has a finger 58 engaged in an opening 60 of a slide 62 connected by bolts 64 with guard plate 50.

The slide 62 has beveled margins 66 movable along a way provided by the fitting 68. This fitting guard is separately illustrated in FIG. 10. Integrally, it has a stop member at 70 and side flanges at 72 which are folded upon themselves and extend upwardly at 74 in pressure engagement with the surfaces 66 of the slide 62. The thrust of the screws 69 which extend through the flanges 72 will adjust the pressure engagement of the flanges with the slide to accommodate the slide adjustment while still tending to retain the slide and the guard frictionally in the position in which the parts have been fixed by the hand lever 54.

As will be observed in FIGS. 2, 3 and 8, the clipper casing 80 is provided behind the motor with a handle portion 82 of reduced cross section. The stand 12 has a fairly deep recess at 84 with downwardly concave sides 86 and a rearwardly sloping front wall 88 (FIG. 2). This recess accommodates that portion of the appliance in which the motor 28 is housed. Behind the recess there is a saddle at 90 defined in part by upstanding posts 92 and 94 and from which a sloping surface 96 extends into recess 84. The guard or fixed clipper blade 50 will seat against the sloping surface 88 at the front of recess 84 regardless of the position to which the guard plate may have been adjusted by the hand lever 54. There is plenty of clearance and the angles are complementary as shown in FIG. 3. The arrangement will accommodate appliances of considerable variation in form or size. When the appliance is a hair clipper, it is advantageous to have the comb plate fit closely to, and receive heat from, the stand surface 88. This surface is kept warm by the transformer 20.

The reduced handle portion 82 of the clipper case will seat on the saddle portion 90 of the stand and will be centered therein by engagement of the complementary surfaces of the clipper and the stand, particular reference being made to the posts 92 and 94 and the surface 96 at the rear of the recess 84. The appliance and the base have complementary contacts hereinafter described which are self-engaging in operative positions without requiring a user to exert any particular care in positioning the appliance when restoring the appliance to the base.

Three sets of complementary contacts are required. The contacts 100 and 102 of the appliance are fixed in the handle portion 82 to be substantially flush with the external surfaces thereof as it appears in FIGS. 2 and 4. Downwardly disposed centrally in the handle portion to be substantially flush with its external surface is a central contact 104. When the appliance is in use, these contacts do not protrude to interrupt the smooth surface of the handle.

All bias required between contacts is preferably provided in the contacts of the stand 10. At opposite sides of the saddle 90 of the stand there are spring contacts 110 and 112 in the posts 92 and 94 and having at their free ends resiliently yieldable terminal portions 114 and 116 respectively. These are under sufficient bias to provide firm engagement with the contacts 100 and 102 of the appliance as best shown in FIG. 4. The springs 110 and 112 are mounted on bosses 118 and 120 of the base 12. The yieldable terminal portions 114 and 116 are exposed through the slots 122 and 124 in the sides of the post portions 92 and 94 which define the saddle.

The central contact 104 of the appliance rests on a contact button 126 which is fixed in practice but may be yieldable if desired. In the circuit hereinafter described, it is desirable that the connections from the stand components to the appliance components be completed through the terminal contacts 100 and 102 in the side posts 92 and 94 prior to completion of the sensing circuit through the central contact 104. This is automatically accomplished when the appliance is restored to the stand, no special care on the part of the operator being required. The advantage lies in the fact that the batteries are subjected to predetermined voltage before the sensing circuit connection is made.

The handle 82 of the appliance houses the batteries 130, 132 and 134. Although it is not essential to the invention, the batteries are preferably arranged with battery 130 extending transversely and batteries 132 and 134 extending side by side in a longitudinal direction as best shown in FIGS. 6 and 7. Connections 136 and 138 controlled by switch 140 provide for controlled supply of current from the batteries to the motor 28.

As above explained, the charging circuit as such is no part of the present invention. It will be described, with particular reference to FIG. 5, and with the understanding that those components below the contacts 100, 102 and 104 are housed in the appliance and those portions above the contacts 114, 126 and 116 in FIG. 5 are housed in the stand. The functioning is as follows:

The charge current source is a high reactance transformer 20 providing only moderate current regulation. The silicon controlled rectifier SCR will pass high rate charge current in successive rectified pulses from the AC source until the reed switch SW is closed by the sensing circuit at a cut off voltage which is temperature compensated. The rectifier CR protects the SCR gate from reverse voltage and rectifies low rate charge current. A resistor R1 limits SCR gate current and in parallel with R2 limits the low rate charging current.

The control element in the temperature compensated sensor circuit is a voltage sensitive relay made up of reed switch SW and coil L1. The sensitivity of the sensor circuit is adjusted by R5 and the relation of high rate charge cut off voltage to battery temperature is governed by thermistor-resistor combination T2-R4. The thermistor-resistor combination T1-R3 compensates the temperature coefficient of resistance of coil L1.

Winding K-L2 produces a magnetic flux during each charge current pulse that opposes the flux produced by K-L1 as a result of battery ripple. Thus the net magnetic flux influencing the reed switch is maximum during the time between charge current pulses. High rate charge cut off must occur during the zero charge current periods. This permits the susceptibility of high rate charge cut off to be minimized with regard to variations in charge circuit impedance and variations in charge current caused by line voltage changes.

Due to the low drop out voltage of the reed switch relay, the battery will remain in low rate charge until circuit continuity is broken. When sensor circuit continuity is re-established the charger will again operate at the high rate until the proper cut off voltage is reached.

If the charge control should fail for any reason, the battery temperature will rise and the fusible link 142 will terminate the charge.

Claims

1. The combination of a cordless hair clipper and a stand, said hair clipper having a shearing head, batteries, and an operating motor and being generally elongated with a handle portion of reduced cross section, and said stand having a recess in which the head of the hair clipper is received when the hair clipper is on the stand and having behind said recess a saddle in which the said handle portion is seated when the hair clipper is not in use, the stand having laterally spaced posts defining said saddle and provided with opposed openings, contacts of the stand consisting of springs having yieldable terminal portions exposed in said openings, said handle portions of said hair clipper having complementary lateral contacts normally engaged with the terminal portions of said posts, and means including a quick charge circuit for current delivery to the batteries and having electrical components including a transformer, rectifying means and voltage control circuit means for reducing the current delivery to a trickle charge when said batteries are operatively charged, with some of the circuit components being physically associated with the stand and others of said components being mounted in said hair clipper and wherein the saddle portion of the stand and the reduced handle portion of the hair clipper have complementary central contacts which, when engaged, complete an operative connection to said voltage control circuit means for rendering said control means effective when current delivery is to be reduced to a trickle charge, the arrangement being such that when the clipper is placed on the stand the connections between the lateral contacts of the clipper and the terminal portions of said first mentioned contact springs are completed prior to the completion of circuit connections to said control means.