Rechargeable hair clipper assembly

A hand-held beauty appliance assembly comprising a hand-held beauty appliance and a battery charger. The hand-held beauty appliance includes an appliance housing portion including a rechargeable battery socket having therein a keyway groove, a frame fixedly supported within the appliance housing portion, an electrical motor fixedly supported on the frame, and a pair of electrical terminals connected to the electrical motor and fixedly supported on the frame. The hand-held appliance also includes a rechargeable battery portion insertable into the battery socket and including a pair of electrical terminals in engagement with the pair of electrical terminals of the appliance housing portion when the rechargeable battery portion is located in the battery socket. The battery portion also includes a keyway slot, a key removably receivable in the keyway groove, a plurality of exterior electrical contacts, and an battery assembly electrically connected to the electrical terminals and to less than all of the plurality electrical contacts.

BACKGROUND OF THE INVENTION 
The invention relates generally to hand-held beauty appliances, such as 
hair clippers, and, more particularly, to rechargeable hair clippers 
including one or more rechargeable batteries. Still more particularly, the 
invention particularly relates to hand held rechargeable hair clippers 
including one or more batteries and to battery recharging devices for the 
batteries in the hand held clipper. 
Attention is directed to the following U.S. Patents: 
Piwaron et al. U.S. Pat. No. 5,088,200 issued Feb. 18, 1992 
Sukow et al. U.S. Pat. No. 5,092,048 issued Mar. 3, 1992 
Andis U.S. Pat. No. 5,230,153 issued Jul. 27, 1993 
Andis et al. U.S. Pat. No. 5,325,590 issued Jul. 5, 1994 
Andis et al. U.S. Pat. No. 5,604,985 issued Feb. 25, 1997 
SUMMARY OF THE INVENTION 
The invention provides an appliance assembly comprising an appliance 
portion including an elongated appliance housing including a rear end 
portion including a rechargeable battery socket with a transverse base 
wall having therein a circular aperture, and an interior wall extending 
from the base wall in the direction of elongation of the appliance housing 
and having therein a keyway groove extending in the direction of 
elongation of the appliance housing, a frame fixedly supported within the 
appliance housing, an electrical motor fixedly supported on the frame 
within the appliance housing, a pair of electrical terminals fixedly 
supported on the frame and in spaced relation to each other, and an 
electrical switch supported by the appliance housing and operatively 
connected between the electrical terminals and the electrical motor, and a 
rechargeable battery portion including a sealed housing having an inner 
end portion removably insertable into the battery socket of the rear end 
portion of the appliance housing and including a pair of electrical 
terminals fixed in spaced relation to each other and in engagement with 
the pair of electrical terminals of the appliance portion when the inner 
end portion of the sealed housing of the rechargeable battery portion is 
located in the battery socket, an outer end portion including an end 
surface, an outer surface extending from the end surface in the direction 
of insertion of the rechargeable battery portion and having therein a 
keyway slot extending in the direction of insertion of the rechargeable 
battery portion, and a plurality of electrical contacts on the outer end 
portion and in a predetermined spaced relation to one another, and an 
intermediate portion located between the inner end portion and the outer 
end portion and having an outer surface including a key extending in the 
direction of insertion of the battery portion and removably receivable in 
the keyway groove in the interior wall of the battery socket of the rear 
end portion of the appliance housing, and a battery assembly located in 
the sealed housing and electrically connected between the pair of 
electrical terminals of the inner end portion of the rechargeable battery 
portion and to less than all of the plurality contacts of the outer end 
portion of the rechargeable battery portion, and a battery charger 
including a charger housing including a socket well removably receiving 
the outer end portion of the rechargeable battery portion and having a 
generally horizontally extending base wall, and a generally vertical wall 
extending from the base wall of the socket well, a vertically extending 
rib extending from the vertical wall and inwardly into the socket well and 
in engagement with the keyway slot of the outer surface of the outer end 
portion of the rechargeable battery portion when the outer end portion of 
the rechargeable battery portion is received in the socket well of the 
charger housing of the battery charger, a plurality of electrical contacts 
located in the socket well in a predetermined relation to one another 
which is the same as the predetermined relation of the plurality of 
contacts of the outer end portion of the rechargeable battery portion and 
in respective engagement with the plurality of contacts of the outer end 
portion of the rechargeable battery portion when the rechargeable battery 
portion is located in the socket well, an electrical cord extending from 
the charger housing and being adapted to be connected to a source of 
electrical current, and a circuit board located within the charger housing 
and including a circuit electrically connected to the electrical cord and 
to less than all of the plurality of contacts located on the vertically 
extending wall of the socket well of the battery charger. 
The invention also provides an appliance assembly including an appliance 
portion including an elongated appliance housing including an outer 
surface, a rear end portion including a rechargeable battery socket with a 
transverse base wall having therein a circular aperture, and an interior 
wall extending from the base wall in the direction of elongation of the 
housing appliance and having therein a keyway groove extending in the 
direction of elongation of the appliance housing, an interior annular 
groove located in axially adjacently spaced relation from the base wall, 
and an opening communicating between the annular groove and the outer 
surface of the appliance housing, a locking ring located in the annular 
groove and including a ring portion defining a bore and including a 
locking segment, and an operating portion located in diametrically opposed 
relation from the locking segment and extending radially from the ring 
portion through the opening communicating between the annular groove and 
the outer surface of the appliance housing, a frame fixedly supported 
within the appliance housing, an electrical motor fixedly supported on the 
frame within the appliance housing, a pair of electrical terminals fixedly 
supported on the frame and extending in spaced relation to each other, an 
electrical switch supported by the appliance housing and operatively 
connected between the electrical terminals and the electrical motor, and a 
spring located in the annular groove and biasing the locking ring to 
normally locate the locking segment inwardly beyond the bore of the 
circular aperture in a locking position and to normally locate the 
operating portion in outwardly projecting relation to the outer surface 
and to permit displacement of the locking ring so as to depress the 
operating portion relative to the outwardly projecting relation and so as 
to displace the locking segment from the locking position and into a 
release position clear of the circular aperture, a rechargeable battery 
portion including a sealed housing having an inner end portion removably 
receivable in the battery socket of the rear end portion of the appliance 
housing and including a flange having a periphery, an annular locking 
groove located axially inwardly from the flange and being lockingly 
engaged by the locking segment of the locking ring when the inner end 
portion of the sealed housing of the rechargeable battery portion is 
located in the battery socket of the rear end portion of the appliance 
housing of the appliance portion, and when the locking ring is in the 
locking position, and a pair of electrical terminals located in fixed 
relation to each other and in engagement with the pair of electrical 
terminals on the frame when the inner end portion of the sealed housing of 
the rechargeable battery portion is located in the battery socket, an 
outer end portion including an end surface, an outer surface extending in 
the direction of insertion of the rechargeable battery portion and having 
therein a keyway slot extending in the direction of insertion of the 
rechargeable battery portion, and a plurality of electrical contacts 
located on the outer end portion and in spaced relation to one another, 
and an intermediate portion located between the inner end portion and the 
outer end portion and having an outer surface extending between the 
locking groove and the outer surface of the outer end portion and 
including a key extending in the direction of insertion of the 
rechargeable battery portion and being removably receivable in the keyway 
groove in the interior wall of the battery socket of the rear end portion 
of the appliance housing, and a battery assembly located in the sealed 
housing and electrically connected between the pair of electrical 
terminals of the inner end portion of the rechargeable battery portion and 
the plurality of contacts of the outer end portion of the rechargeable 
battery portion, and a battery charger including a charger housing 
including a socket well removably receiving the outer end portion of the 
rechargeable battery portion and having a generally horizontally extending 
base wall, and a generally vertical wall extending from the base wall of 
the socket well, a rib extending inwardly into the socket well and into 
removable engagement with the keyway slot of the outer surface of the 
outer end portion of the rechargeable battery portion when the outer end 
portion of the rechargeable battery portion is received in the socket well 
of the charger housing of the battery charger, a plurality of electrical 
contacts located in the socket well and in spaced relation to one another 
and in respective engagement with the plurality of contacts on the outer 
end portion of the rechargeable battery portion when the rechargeable 
battery portion is located in the socket well, an electrical cord 
extending from the charger housing and being adapted to be connected to a 
source of electrical current, and a circuit board located within the 
charger housing and including a circuit electrically connected between the 
electrical cord and the plurality of contacts in the socket well of the 
battery charger. 
The invention also provides a hair clipper assembly comprising a hair 
clipper including a clipper portion including an elongated clipper housing 
assembly including a first half-section, a second half-section mating with 
the first half-section, an outer surface, a rear end portion defined by 
the first and second half-sections and including a rechargeable battery 
socket of non-circular cross-sectional configuration and with a transverse 
base wall having therein a circular aperture, and an interior wall 
extending from the base wall in the direction of elongation of the clipper 
housing assembly and having therein a keyway groove extending in the 
direction of elongation of the clipper housing assembly, an interior 
annular groove located in axially adjacently spaced relation from the base 
wall, and an opening communicating between the annular groove and the 
outer surface of the first half-section of the clipper housing assembly, a 
front end portion, and an intermediate portion defining an interior cavity 
and including interior wall surfaces, a locking ring located in the 
annular groove and including a ring portion defining a bore and including 
a locking segment, and an operating portion located in diametrically 
opposed relation from the locking segment and extending radially from the 
ring portion through the opening communicating between the annular groove 
and the outer surface of the first half-section of the clipper housing 
assembly, a blade set carried by the front end portion of the clipper 
housing assembly, a frame fixedly supported within the clipper housing 
assembly by the interior wall surfaces, an electrical motor fixedly 
supported on the frame within the clipper housing assembly and drivingly 
connected to the blade set, a pair of electrical terminals fixedly 
supported on the frame and extending in spaced parallel relation to each 
other and through the circular aperture into the battery socket, an 
electrical switch supported by the first half-section of the clipper 
housing assembly and operatively connected between the electrical 
terminals and the electrical motor, and a spring biasing the locking ring 
so as to normally locate the operating portion in outwardly projecting 
relation to the outer surface, and so as to normally locate the locking 
segment inwardly within the circular aperture in a locking position, 
thereby permitting inward displacement of the operating portion from the 
outwardly projecting relation and displacement of the locking segment from 
the locking position and into a release position clear of the circular 
aperture, a rechargeable battery portion including a sealed housing having 
a battery assembly located in the sealed housing and electrically 
connected between the pair of electrical terminals extending from the 
inner end portion and the plurality contacts located adjacent the end 
surface of the outer end portion, a circular inner end portion removably 
receivable in the battery socket of the rear end portion of the clipper 
housing assembly of the hair clipper portion and including a flange 
defining an inner end of the inner end portion and having a periphery, an 
annular locking groove located axially inwardly from the flange and being 
lockingly engaged by the locking segment of the locking ring when the 
inner end portion of the sealed housing of the rechargeable battery 
portion is located in the battery socket of the rear end portion of the 
clipper housing assembly, and when the locking ring is in the locking 
position, and a pair of electrical terminals extending in spaced parallel 
relation to each other within the periphery of the flange, in electrical 
connection with the battery assembly, and in engagement with the pair of 
electrical terminals extending through the circular aperture into the 
battery socket when the inner end portion of the sealed housing of the 
rechargeable battery portion is located in the battery socket, an outer 
end portion including a dome-shaped end surface, an outer surface having a 
generally cylindrical cross-sectional configuration, extending from the 
end surface, and having therein an axially extending keyway slot, and four 
electrical contacts located adjacent the end surface and in a circular 
array in evenly spaced arcuate relation to one another and including two 
of the four contacts in electrical connection with the battery assembly 
and with the pair of electrical terminals extending from the inner end 
portion of the rechargeable battery portion, and at least one of the four 
contacts being electrically unconnected, and an intermediate portion 
located between the inner end portion and the outer end portion and having 
an outer surface of non-circular cross-section corresponding to the 
non-circular cross-section of the socket well of the rear end portion of 
the clipper housing assembly and extending from the locking groove and to 
the circular outer surface of the outer end portion of the rechargeable 
battery portion and including an axially extending key removably 
receivable in the keyway groove in the axially extending interior wall of 
the battery socket of the rear end portion of the clipper housing assembly 
of the hair clipper portion, and a battery charger including a charger 
housing including a socket well removably receiving the outer end portion 
of the rechargeable battery portion and having a generally horizontally 
extending base, and a generally vertically extending cylindrical wall 
having a generally cylindrical cross-sectional configuration corresponding 
to the cylindrical cross-sectional configuration of the outer surface of 
the outer end of the rechargeable battery portion, a vertically extending 
rib extending from the vertically extending cylindrical wall and inwardly 
into the socket well and in engagement with the axially extending keyway 
slot of the outer circular surface of the outer end portion of the 
rechargeable battery portion when the outer end portion of the 
rechargeable battery portion is received in the socket well of the charger 
housing of the battery charger, four electrical contacts located on the 
vertically extending circular wall adjacent the base and in a circular 
array in evenly spaced arcuate relation to one another, in respective 
engagement with the plurality of contacts on the outer circular surface of 
the outer end portion of the rechargeable battery portion when the 
rechargeable battery portion is located in the socket well, and including 
at least one of the four contacts located on the vertically extending 
circular wall being electrically unconnected, an electrical cord extending 
from the charger housing and being adapted to be connected to a source of 
electrical current, and a circuit board located within the charger housing 
and including a circuit electrically connected between the electrical cord 
and at least two of the four contacts located on the vertically extending 
circular wall of the socket well of the battery charger. 
Other features and advantages of the invention will become apparent to 
those skilled in the art upon review of the following detailed 
description, claims and drawings.

Before one embodiment of the invention is explained in detail, it is to be 
understood that the invention is not limited in its application to the 
details of the construction and the arrangements of components set forth 
in the following description or illustrated in the drawings. The invention 
is capable of other embodiments and of being practiced or being carried 
out in various ways. Also, it is understood that the phraseology and 
terminology used herein is for the purpose of description and should not 
be regarded as limiting. 
DESCRIPTION OF THE PREFERRED EMBODIMENT 
Shown in FIG. 1 is a hair clipper assembly 11 which incorporates various of 
the features of the invention and which includes a rechargeable 
battery-operated hair clipper 13 and a battery charger 15. In turn, the 
rechargeable battery-operated hair clipper 13 includes a clipper portion 
17 and a rechargeable battery portion 19. 
The clipper portion 17 includes (see FIGS. 2, 3, and 4) an elongated 
clipper housing or housing assembly 21 which includes a forwardly and 
rearwardly extending axis of elongation 23, and an outer surface 25. While 
various constructions can be employed, it is preferred that the clipper 
housing 21 be fabricated from electrically insulating plastic material to 
include mating upper and lower half-sections 27 and 29 which can be 
secured or assembled together by any suitable arrangement including screws 
(not shown). Preferably, the upper and lower half-sections 27 and 29 are 
also held in assembled relation by an endless resilient O-ring 30 which is 
located in an annular recess in the outer surface 25 of the rearward 
portion of the housing assembly 21. 
The clipper housing assembly or housing assembly 21 also includes a front 
end or forward portion 31 and a rear end or rearward portion 33 which 
includes a battery socket 35 defined by a transverse base wall 37 having 
therein a circular opening or aperture 39. The battery socket 35 is also 
defined by an interior wall 41 which extends rearwardly and axially from 
the base wall 37 and which is preferably of generally cylindrical 
configuration. In addition, the interior wall 41 is preferably provided 
with a plurality of axially spaced, transverse ribs 43 which effectively 
provide the battery socket 35 with a non-circular cross-section 
transversely of the axis of elongation, which cross-section, in the 
disclosed construction, is generally square. The interior wall 41 also has 
therein an axially extending keyway groove 45 which extends through the 
ribs 43. 
The rear end or rearward portion 33 also includes, in axially adjacent and 
spaced relation to the base wall 37, a radially inwardly extending flange 
51 which is centrally apertured and which, together with the base wall 37, 
defines an interior annular groove 53. In addition, the rear end or 
rearward end portion 33 also includes, in the upper housing half-section 
27, an opening 55 communicating between the annular groove 53 and the 
outer surface 25 of the clipper housing or housing assembly 21. 
The rear end or rearward portion 33 of the clipper housing assembly 21 also 
includes a locking ring 61 which is fabricated, separately from the 
clipper housing assembly 21, from electrically insulating plastic 
material, which is located in the annular groove 53 and which includes a 
ring portion 63 and, preferably, an integrally connected spring portion 
64. The ring portion 63 includes (see FIG. 11) a central bore 65, and a 
locking segment 67, and an operating portion 69 which is located in 
diametrically opposed relation from the locking segment 67, which extends 
radially from the ring portion 63 and through the opening 55, and which 
normally projects from the outer surface 25 of the upper half-section 27 
of the clipper housing assembly 21. The locking segment 67 is provided, on 
the rearwardly facing edge thereof, with an inclined camming surface 71 
which extends for approximately 180 degrees and which cooperates with a 
camming surface still to be described on the rechargeable battery portion 
19. 
The spring portion 64 biases the locking ring 61 to normally locate the 
locking segment 67 inwardly beyond the periphery of the circular aperture 
39 in a locking position and to normally locate the operating portion 69 
in outwardly projecting relation to the outer surface 25 of the upper 
housing half-section 27 and so as to permit displacement of the locking 
ring 61 relative to the housing assembly 21 so as to depress the operating 
portion 69 from the outwardly projecting relation to the upper housing 
half-section 27 and so as to displace the locking segment 67 from the 
locking position and into a release position clear of the circular 
aperture 39. 
If desired, the ring portion 63 and the spring portion 64 can be separately 
fabricated. 
The clipper housing assembly 21 also includes (see FIG. 4) an intermediate 
portion 81 which is located between the front end or forward portion 31 
and the rear end or rearward portion 33, which defines an interior cavity 
83, and which includes interior wall surfaces 85. 
The clipper portion 17 also includes a blade set 91 which can be of any 
conventional construction and which is suitably mounted on the front end 
or forward portion 31 of the clipper housing assembly 21 and, more 
specifically, on the forward end of the lower clipper housing half-section 
29. 
The clipper portion 17 also includes a frame 101 which is preferably 
fabricated of electrically insulating plastic material, which is fixedly 
supported within the clipper housing or housing assembly 21, and which 
includes wall surfaces 103 engaged by the interior wall surfaces 85 of the 
intermediate portion 81 of the clipper housing 21 in such manner as to 
prevent movement of the frame 101 relative to the clipper housing 21 in 
the direction of elongation of the clipper housing 21 and in all 
directions transverse to the direction of elongation. If desired, the 
frame can also be connected to the housing assembly 21 by one or more 
screws (not shown), or by a combination of screws and engaged surfaces. 
The clipper portion 17 also includes an electrical motor 111 which can be 
of any suitable construction and which is suitably fixedly supported on 
the frame 101 within the clipper housing assembly 21 and drivingly 
connected to the blade set 91 through a blade drive assembly 121 which can 
be of any suitable construction. 
The clipper portion 17 also includes (see FIG. 8) a pair of electrical 
terminals 131 which can be of any suitable construction, which are fixedly 
supported on the frame 101 by any suitable arrangement, such as the 
disclosed screws 132, and which, in the disclosed construction, include 
respective unshaped portions extending rearwardly in spaced parallel 
relation to each other, through the circular aperture 39, and into the 
battery socket 35. 
The clipper portion 17 also includes (see FIG. 4) an electrical off-on 
switch 133 which can be of any suitable construction, which is suitably 
supported by the upper housing half-section 27, which includes an axially 
moveable switch operating member 135, and which is operatively connected 
between the electrical terminals 131 and the electrical motor 111. 
The rechargeable battery portion 19 includes (see FIGS. 3 and 7) a sealed 
housing 161 which is preferably fabricated of electrically insulating 
plastic material in two half segments which are sonically or otherwise 
welded to each other. The sealed housing includes a circular inner end 
portion 163 which is removably receivable in the battery socket 35 of the 
rear end or rearward portion 33 of the clipper housing assembly 21. The 
circular inner end portion 163 includes an annular flange 165 having a 
periphery, and an annular locking groove 167 which is located axially 
rearwardly from the annular flange 165, which is defined by the annular 
flange 165 and by an adjacent shoulder 169, and which is lockingly engaged 
by the locking segment 67 of the locking ring 61 when the inner end 
portion 163 of the sealed housing 161 of the rechargeable battery portion 
19 is located in the battery socket 35 of the rear end or rearward portion 
33 of the clipper housing assembly 21, and when the locking ring 61 is in 
the locking position. 
The annular flange 165 is provided (see especially FIG. 7) with an inclined 
camming surface 166 which extends arcuately for approximately 180 degrees 
along the lower half of the annular flange 165 and which, consequent to 
insertion of the battery portion 19 into the battery socket 35, engages 
the camming surface 71 on the locking ring 61 to displace the locking ring 
61, against the action of the spring portion 64, to a position permitting 
insertion of the annular flange 165 inwardly beyond the locking ring 61 
and subsequent movement of the locking ring 61 into the locking position 
in the annular groove 167 in the rechargeable battery portion 19. 
The inner end portion 163 of the rechargeable battery portion 19 also 
includes a pair of electrical terminals 171 extending in spaced parallel 
relation to each other within the periphery of the annular flange 165 and 
in engagement with the pair of electrical terminals 131 extending through 
the circular aperture 39 into the battery socket 35 when the inner end 
portion 163 of the sealed housing 161 of the rechargeable battery portion 
19 is located in the battery socket 35. 
The rechargeable battery portion 19 also includes an outer end portion 181 
including a dome-shaped end surface 183, an outer generally cylindrical or 
slightly tapered surface or wall 185 extending axially inwardly from the 
dome-shaped end surface 183. The outer end portion 181 also includes (see 
FIG. 5) an axially extending keyway slot 187 which cooperates with the 
battery charger 15 as will be disclosed. 
The outer end portion 181 also includes a plurality of electrical contacts 
191 which are arranged in a circular array in evenly spaced arcuate 
relation to one another and adjacent the dome-shaped end surface 181. The 
electrical contacts 191 include respective outer portions 193 located in 
slightly depressed relation to the cylindrical surface or wall 185 and 
(see FIG. 6) respective inner portions 195 extending into the interior of 
the sealed housing 161 for electrical connection as will be disclosed. 
While other constructions can be employed, in the specifically disclosed 
construction, the electrical contacts 191 are four in number and include 
(see FIG. 5) first, second, third, and fourth contacts 192, 194, 196, and 
198. 
The rechargeable battery portion 19 also includes an intermediate portion 
201 located between the inner end portion 163 and the outer end portion 
181 and having a non-circular outer surface 203 which, preferably, is 
generally square, which extends from the locking groove 167 or shoulder 
169 and to the outer end portion 181, and which mates with the 
non-circular cross-section of the interior wall 41 of the battery socket 
35 to stabilize the sealed housing 161 in the battery socket 35. 
In addition, the non-circular outer surface 203 of the intermediate portion 
201 includes an axially extending key 207 removably receivable in the 
keyway groove 45 in the axially extending interior wall 41 of the battery 
socket 35 of the rear end portion 33 of the housing assembly 21 of the 
clipper portion 17. In addition, receipt of the key 207 in the groove 45 
insures correct alignment of the electrical terminals 131 extending from 
the frame 101 and the electrical terminals 171 extending from the 
rechargeable battery portion 17 and enables proper engagement between the 
electrical terminals 131 and 171 incident to insertion of the rechargeable 
battery portion 19 into the battery socket 35 of the clipper portion 17. 
Enclosed in the sealed housing 161 is (see FIG. 13) a battery assembly 211 
including a plurality of rechargeable batteries 213 electrically connected 
to the electrical terminals 171 and 191. Any suitable rechargeable 
batteries can be employed. 
The battery charger 15 includes (see FIGS. 1, 6, 9, 10, 11, and 12) a 
charger housing 221 which is preferably fabricated of electrically 
insulating plastic material and which includes a socket well 223 which 
removably receives the outer end portion 181 of the rechargeable battery 
portion 19 and which has a generally horizontally extending and concavely 
shaped base wall 225. 
In addition, the socket well 223 of the battery charger 15 also includes a 
cylindrical or slightly tapered wall 227 which extends generally 
vertically from the base wall 225, and a vertically extending rib 229 
which extends from the vertically extending wall 227 and inwardly into the 
socket well 223 and into engagement with the axially extending keyway slot 
187 (FIG. 5) of the outer surface 185 of the outer end portion 181 of the 
rechargeable battery portion 19 when the outer end portion 181 of the 
rechargeable battery portion 19 is received in the socket well 223 of the 
charger housing 161 of the battery charger 15. Engagement of the rib 229 
in the keyway slot 187 serves to properly locate the rechargeable battery 
portion 19 relative to the batter charger 15. 
Still further in addition, the socket well 223 of the battery charger 15 
also includes (see FIG. 6) a plurality of electrical contacts 231 which 
can be of any suitable construction, and which are equal in number to the 
plurality of contacts 191 on the rechargeable battery portion 19. Thus 
while other constructions can be employed, in the specifically disclosed 
construction, the contacts 231 are four in number and comprise (see FIG. 
9) first, second, third, and fourth contacts 232, 234, 236, and 238 which, 
when the rechargeable battery portion is in the socket well 223 of the 
battery charger 15, respectively engage first, second, third, and fourth 
contacts 192, 194, 196, and 198. 
The electrical contacts 231 respectively include (see FIG. 6) outer 
portions 233 located within the socket well 223, interiorly of the 
vertical surface or wall 227, and in a circular array in evenly spaced 
arcuate relation to one another and adjacent the base wall 225, and in 
respective engagement with the plurality of contacts 191 on the outer 
surface 185 of the outer end portion 181 of the rechargeable battery 
portion 19 when the rechargeable battery portion 19 is located in the 
socket well 223. In addition, the plurality of contacts 231 include 
respective inner portions 235 extending into the interior of the charger 
housing 221 for electrical connection as will be disclosed. 
The battery charger 15 includes (see FIG. 1) an electrical cord 241 
extending from the charger housing 221 and adapted to be connected to a 
source of electrical current. In addition, the battery charger 15 also 
includes (see FIG. 12) a circuit board 251 located within the charger 
housing 221 and having mounted thereon a battery charging circuit 261 
which is shown schematically in FIG. 15, and which is electrically 
connected between the electrical cord 241 and the plurality of contacts 
231 located on the vertically extending cylindrical wall 227 of the socket 
well 223 of the battery charger 15. 
In one particular embodiment, as shown in FIGS. 13, 14 and 15, the battery 
assembly 211 includes (see FIGS. 13 and 14) three batteries 213 which are 
nestled together, in any suitable manner, to provide a compact battery 
pack 271, which are connected together in series with one another and with 
a suitable polyswitch 273, and which are connected to a positive terminal 
275 and to a negative terminal 277. The battery pack 271 also includes a 
first lead 281 which is connected between the positive terminal 275 and 
one of the pair of terminals 171 extending from the inner end portion 163 
of the rechargeable battery portion 19, and a second lead 283 which 
extends from the positive terminal 275 to the first contact 192 of the 
plurality of contacts 191 on the outer end portion 181 of the rechargeable 
battery portion 19, which first contact 192 engages the first contact 3 of 
the plurality of contacts 231 in the socket well 223 of the battery 
charger 15 when the rechargeable battery portion 19 is in the socket well 
223 of the battery charger 15. 
The battery pack 271 also includes a third lead 301 which is connected 
between the negative terminal 277 and the other one of the pair of 
terminals 171 extending from the inner end portion 163 of the rechargeable 
battery portion 19, and a fourth lead 303 which extends from the negative 
terminal 277 to the second contact 194 of the plurality of contacts 191 on 
the outer end portion 181 of the rechargeable battery portion 19, which 
second contact 194 engages the second contact 234 of the plurality of 
contacts 231 in the socket well 223 of the battery charger 15 when the 
rechargeable battery portion 19 is in the socket well 223 of the battery 
charger 15. The third contact 196 and the fourth contact 198 of the 
plurality of contacts 191 respectively engage the third contact 236 and 
the fourth contact 238 of the plurality of contacts 231 in the socket well 
223 of the battery charger 15 when the rechargeable battery portion 19 is 
in the socket well 223 of the battery charger 15 and are electrically 
unconnected within the rechargeable battery portion 19. In addition, the 
contacts 236 and 238 are electrically unconnected within the battery 
charger 15. 
The battery charging circuit 261 includes (see FIG. 15), in general terms, 
a power supply circuit 351, a pair of indicator circuits 353 and 355, a 
reconfigure/timer circuit 357 a boost charge circuit 359, and a discharge 
circuit 361. The battery charging circuit 261 operates, in general, to 
effect full discharge and recharge of the batteries 213. 
The power supply circuit 351 is adapted to be connected to an alternating 
current source of electrical power. In the embodiment shown in FIG. 15, 
the power supply circuit 351 is connected to a 120 volt, 60 hertz 
alternating current source of electrical power. The power supply circuit 
351 includes a power transformer T1 connected to a full-wave bridge 
rectifier that converts the alternating current voltage into direct 
current (d.c.) voltage at 12 volts. The power supply circuit 351 also 
includes capacitor C2 and C3 for filtering and smoothing the rectified 
voltage as well as zener diode ZD1 which acts as a shunt regulator to 
"bleed off" any voltage in excess of 5 volts d.c. 
The reconfigure/timer circuit 357 is connected to the power supply circuit 
573 and includes an integrated circuit timer IC1. In the embodiment shown 
in the drawings, the timer IC1 is a Motorola MC14541BCP integrated circuit 
timer. The reconfigure/timer circuit 357 also includes transistors Q5 and 
Q6. The timer IC1 is configured to send control signals to the discharge 
circuit 361 and the boost charge circuit 359 via transistors Q5 and Q6. 
The boost charge circuit 359 includes timer IC2 and transistor Q7. In the 
embodiment shown in FIG. 15, timer IC2 is a Motorola MC14541 BCP 
integrated circuit timer. The boost charge circuit 359 also includes drive 
transistors Q1 and Q3 and resistor RIO which form a power switch network 
that increases the charge current flowing to the batteries 213 in the 
boost charge operating mode. 
The discharge circuit 361 includes timer IC3. In the embodiment shown in 
FIG. 15, timer IC3 is a Motorola MC14541 BCP integrated circuit timer. 
Timer IC3 is connected to an off-on switch S (also identified by the 
numeral 593 in FIG. 1) which is a momentary switch. Timer IC3 is also 
connected to switch FET1 which is a field effect transistor. The off-on 
switch S (593) is mounted on the charger housing 221 adjacent to the 
charging and discharging indicators 573 and 575. Switch FET1 is connected 
to the power supply circuit 351 via series connected diodes D8, D9 and D10 
and resistor R6. 
The indicator circuits 353 and 355 respectively include visual indicators 
LED1 and LED2. In the embodiment shown in FIG. 15, the visual indicators 
LED1 and LED2 are light emitting diodes. However, any visual or audible 
indicator may be appropriate under various circumstances. As will be 
described in greater detail below, visual indicators LED1 and LED2 are lit 
to indicate the various operating states of the battery charge circuit 
261. The visual indicator LED1 is electrically driven by transistor Q2 and 
the visual indicator LED2 is electrically driven by transistor Q4. More 
particularly, the light emitting diode LED1 is also identified in FIG. 1 
by the numeral 573, is mounted on the charger housing 221, is preferably 
of one color, such as green, and is illuminated during battery charging. 
The second light emitting diode LED2 is also identified in FIG. 1 by the 
numeral 575, is mounted on the charger housing 221 adjacent the charging 
indicator 573 (LED1), is preferably of another color, such as red, and is 
illuminated during battery discharging. 
As shown in FIG. 15, the battery charging circuit 261 also includes a first 
lead 581 which is connected to the first contact 232 of the plurality of 
contacts 231 in the socket well 223, which first contact 232 engages the 
first contact 192 of the plurality of contacts 191 on the outer end 
portion 181 of the rechargeable battery portion 19 when the rechargeable 
battery portion 19 is in the socket well 223 of the battery charger 15. 
The battery charging circuit 261 also includes a second lead 583 which is 
connected to the second contact 234 of the plurality of contacts 231 in 
the socket well 223, which second contact 234 engages the second contact 
194 of the plurality of contacts 191 on the outer end portion 181 of the 
rechargeable battery portion 19 when the rechargeable battery portion 19 
is in the socket well 223 of the battery charger 15. The third and fourth 
contacts 196 and 198 of the plurality of contacts 191 are electrically 
unconnected to the battery pack 271 and the third and fourth contacts 236 
and 238 of the plurality of contacts 231 in the socket well 233 are 
electrically unconnected to the battery charging circuit 261. 
In operation, the battery charge circuit 261 is connected to an appropriate 
alternating current source of electrical power. Whether the rechargeable 
battery portion 19 is or is not connected to the battery charge circuit 
261, i.e., the rechargeable battery portion 19 is or is not in the socket 
well 223, both timers IC1 and IC3 are initialized. As long as timer IC3 is 
operating, the charge circuit 261 is in the battery discharge mode. That 
is, switch FET1 is closed so that current is being conducted from the 
power supply circuit 573 through resistor diodes D8, D9 and D10. Timer IC3 
is configured to run for 15 seconds without the rechargeable battery 
portion 19 connected to the battery charge circuit 261. After the 15 
second time period has elapsed, timer IC3 turns off and timer IC2 is 
initialized to begin a short boost charge period. In this operating state, 
i.e., without the rechargeable battery portion 19 connected to the battery 
charge circuit 261, timer IC2 is configured to operate for a 45 second 
period. After the end of the 45 second period, the boost charge function 
is turned off and the trickle charge, controlled by timer IC1, continues 
for the 30 seconds remaining in the operating period of timer IC1. At the 
end of the 30 second period, both the discharge timer IC3 and the boost 
charge timer IC2 are configured to run for one hour and three hours, 
respectively. 
When the rechargeable battery portion 19 is connected to the battery charge 
circuit 261, the batteries 213 are trickle charged, i.e., charged slowly 
using a relatively low current flow, at a rate determined by resistor R3 
of the power supply circuit 573. When the switch S is depressed by the 
user of the appliance, discharge timer IC3 is turned on for a period of 
one hour thereby closing switch FET1 to cause discharge of the remaining 
power in the batteries 213 in the rechargeable battery portion 19 through 
resistor R6 diodes D8, D9 and D10 and switch FET1. Serially connected 
diodes D8, D9 and D10 prevent the batteries 213 in the rechargeable 
battery portion 19 from being discharged too low. Draining the individual 
batteries 213 in the rechargeable battery portion 19 too low could cause 
reversal of one of the individual batteries 213. When several batteries 
are connected in series, batteries with a higher capacity may cause a 
reversal of the polarity of the weaker batteries during battery discharge. 
The series connected diodes D8, D9 and D10 prevent any reversal in the 
polarity of the batteries 213 in the rechargeable battery portion 19 
during discharge of the rechargeable battery portion 19. 
The rechargeable battery portion 19 can be discharged, in response to 
manual actuation of the switch S, before the beginning of the charge cycle 
in order to eliminate any adverse memory effect on the rechargeable 
battery portion 19. Whenever the battery charge circuit 261 is in the 
discharge mode, visual indicator LED1 turns on to indicate that discharge 
is taking place. 
When the one hour discharge period for discharge timer IC3 expires, boost 
charge timer IC2 is automatically started for a period of three hours. The 
boost charge circuit generates a high current source for charging the 
battery quickly for a three hour period. When the three hour boost charge 
timer period expires, the boost charge circuit 359 turns off and the 
battery charge circuit 261 continues to trickle charge the rechargeable 
battery portion 19 at a rate determined by resistor R3. The trickle charge 
rate runs continuously for as long as the rechargeable battery portion 19 
is connected to the battery charge circuit 261. 
Whenever the battery charge circuit 261 is in the charge mode, either in 
the boost charge operating mode or in the trickle charge operating mode, 
visual indicator LED2 is turned on by the voltage drop that occurs when 
the rechargeable battery portion 19 is connected to the battery charge 
circuit 261. 
In another particular embodiment, as shown in FIGS. 16, 17 and 18, the 
battery assembly 211 includes (see FIGS. 16 and 17) four batteries 213 
which are nestled together in a battery pack 511 to provide a compact 
assembly, which are connected together, in any suitable manner, in series 
with one another and with a suitable polyswitch 513 and with a thermostat 
515, and which are connected to a positive terminal 521 and to a negative 
terminal 523. In addition, the battery pack 511 also includes, at one end 
of the battery pack 511, a first lead 531 which is connected between the 
positive terminal 521 and one of the pair of electrical terminals 171 
extending from the inner end portion 163 of the rechargeable battery 
portion 19, and a second lead 533 which extends from the positive terminal 
521 to the first contact 192 of the plurality of contacts 191 on the outer 
end portion 181 of the rechargeable battery portion 19, which first 
contact 192 engages the first contact 232 of the plurality of contacts 231 
in the socket well 223 of the battery charger 15 when the rechargeable 
battery portion 19 is in the socket well 223 of the battery charger 15. 
The battery pack 511 also includes a third lead 541 which is connected 
between the negative terminal 523 and the other one of the pair of 
electrical terminals 171 extending from the inner end portion 163 of the 
rechargeable battery portion 19, and a fourth lead 543 which extends from 
the negative terminal 523 to the second contact 194 of the plurality of 
contacts 191 on the rechargeable battery portion 19, which second contact 
194 engages the second contact 234 of the plurality of contacts 231 in the 
socket well 223 of the battery charger 15 when the rechargeable battery 
portion 19 is in the socket well 223 of the battery charger 15. 
Still further in addition, the battery pack 511 includes a thermistor 551 
which is nestled together with the four batteries 213 in the battery pack 
511, which extends from a point in adjacent relation to the other end of 
the battery pack 511, and which is connected by a fifth lead 561 to the 
third contact 196 of the plurality of contacts 191 on the outer end 
portion 181 of the rechargeable battery portion 19, which third contact 
196 engages the third contact 236 of the plurality of contacts 231 in the 
socket well 223 of the battery charger 15 when the rechargeable battery 
portion 19 is in the socket well 223 of the battery charger 15. 
If desired to provide superior reliability, the thermistor 551 can also be 
connected by a sixth lead 563 which extends in parallel to the fifth lead 
561 and which is connected to the fourth contact 198 of the plurality of 
contacts 191 on the outer end portion 181 of the rechargeable battery 
portion 19, which fourth contact 198 engages the fourth contact 238 of the 
plurality of contacts 231 in the socket well 223 of the battery charger 15 
when the rechargeable battery portion 19 is in the socket well 223 of the 
battery charger 15. 
Alternatively, if desired, the sixth lead 563 can be omitted, and when 
omitted, the fourth contact 198 of the plurality of contacts 191 on the 
outer end portion 181 of the rechargeable battery portion 19 is 
electrically unconnected within the rechargeable battery portion 19 and 
the fourth contact 238 of the plurality of contacts 231 in the socket well 
223 is electrically unconnected within the battery charger 15. 
The embodiment of FIGS. 16, 17, and 18 also includes, as shown in FIG. 18, 
a battery charge circuit 611 including a power supply circuit 613, a power 
switch circuit 615, a pair of indicator circuits 617 and 619, and a charge 
control circuit 621. 
The power supply circuit 613 is adapted to be connected to a source of 
electrical power which, in the embodiment shown in FIG. 18, is a 120 volt, 
60 Hz source of alternating current. The power supply circuit 613 includes 
a power transformer T1 connected to a full-wave bridge rectifier including 
diodes D1, D2, D3 and D4 in a wheatstone bridge configuration. The bridge 
rectifier is connected to capacitor C2, C4, and C7 via fuse FS1. 
Capacitors C2, C4 and C7 filter and smooth the rectified waveform to 
provide a 5 volt direct current (d.c.) source of power for the battery 
charge control circuit 621. The power supply circuit 613 also includes 
zener diode ZD1 which operates as a shunt regulator to "bleed off" any 
voltage above the 5 volt level. 
The power switch circuit 615 selectively connects the rechargeable battery 
portion 19 to the power supply circuit 613 so as to charge the battery 
pack or assembly 511. The power switch circuit 615 also includes a silicon 
controlled rectifier SCR1, and transistor switches Q1, Q2 and Q3 for 
providing a gate signal to switch off SCR1. 
The charge control circuit 621 is connected to the power supply circuit 613 
and to the power switch circuit 615. The charge control circuit 621 
includes applicable electrical contacts which connect the battery charge 
circuit 621 to the rechargeable battery portion 19 when the rechargeable 
battery portion 19 is located in the socket well 223 of the battery 
charger 15. More specifically, the charge control circuit 621 includes a 
first lead 631 which is connected to the first contact 232 of the 
plurality of contacts 231 in the socket well 223, which first contact 232 
engages the first contact 192 of the plurality of contacts 191 on the 
outer end portion 181 of the rechargeable battery portion 19 when the 
rechargeable battery portion 19 is in the socket well 223 of the battery 
charger 15. The charge control circuit 621 also includes and a second lead 
633 which is connected to the second contact 234 of the plurality of 
contacts 231 in the socket well 223, which second contact 234 engages the 
second contact 194 of the plurality of contacts 191 on the outer end 
portion 181 of the rechargeable battery portion 19 when the rechargeable 
battery portion 19 is in the socket well 223 of the battery charger 15. 
In addition, the charge control circuit 621 also includes another lead 635 
which is connected to the third contact 236 of the plurality of contacts 
231 in the socket well 223, which third contact 236 engages the third 
contact 196 of the plurality of contacts 191 on the outer end portion 181 
of the rechargeable battery portion 19 when the rechargeable battery 
portion 19 is in the socket well 223 of the battery charger 15. 
Still further in addition, when the thermistor 551 is connected to the 
sixth lead 563, the charge control circuit 621 also includes still another 
lead 637 which extends in parallel to the lead 635 and which is connected 
to the fourth contact 238 of the plurality of contacts 231 in the socket 
well 223, which fourth contact 238 engages the fourth contact 198 of the 
plurality of contacts 191 on the outer end portion 181 of the rechargeable 
battery portion 19 when the rechargeable battery portion 19 is in the 
socket well 223 of the battery charger 15. 
When the sixth lead 563 (which extends from the thermistor 551) is omitted, 
the fourth contact 238 of the plurality of contacts 231 in the socket well 
223 is electrically unconnected within the charger housing 221. 
The charge control circuit 621 also includes a charge storage capacitor C1 
which is connected in parallel relation to the electrical contacts 232 and 
234 so that, when the rechargeable battery portion 19 is connected to the 
battery charger circuit 261, the capacitor C1 is in parallel relation with 
the rechargeable battery portion 19. 
The charge control circuit 621 also includes a resistor divider network 
consisting of resistors R2 and R11 is connected in parallel relation with 
the capacitor C1. The resistor divider network is connected to a charge 
control integrated circuit IC1. The charge control integrated circuit is, 
in the embodiment shown in the drawings, a BQ2002TPN Benchmarq integrated 
circuit. The charge control integrated circuit IC1 is connected to the 
power switch circuit 343 to provide a control signal for triggering switch 
SCR1. 
The charge control circuit 621 also includes thermistor R14 which is also 
identified by the numeral 551 in FIGS. 16 and 17, which, as already noted, 
is a part of the battery pack 511, and which connects with the remainder 
of the charge control circuit 621 through the contacts 196 and 236 and 
lead 635, and via the resistor divider network formed by resistors R12 and 
R13 whenever the rechargeable battery portion 19 is placed in the socket 
well 223. 
The indicator circuits 617 and 619 respectively include first or charging 
and second or discharging visual indicators LED1 and LED2. In the 
embodiment shown in FIG. 18, the first and second visual indicators LED1 
and LED2 are light emitting diodes. However, any visual or audible 
indicator may be appropriate under various circumstances. As will be 
described in greater detail below, visual indicators LED1 and LED2 are lit 
to indicate the various operating states of the battery charge circuit 
611. The visual indicators LED1 and LED2 are electrically driven by 
transistors Q6 and Q7, and Q4 and Q5, respectively. More particularly, the 
first visual indicator or charging indicator or light emitting diode LED1 
is also identified by the numeral 573 in FIG. 1, is mounted on the charger 
housing 221 adjacent the socket well 223, is preferably of one color, such 
as green, and is illuminated during battery charging. The second visual 
indicator or discharging indicator or light emitting diode LED2 is also 
identified by the numeral 575 in FIG. 1, is mounted on the charger housing 
221 adjacent the charging indicator 573, is preferably of another color, 
such as red, and is illuminated during battery charging. 
In operation, with the battery charge circuit 611 connected to an 
appropriate alternating current source of electrical power, and before the 
rechargeable battery portion 19 is connected to the battery charge circuit 
611, a peak DC voltage is stored on capacitor C1. This peak DC voltage 
allows the charge control circuit 621 to detect when the rechargeable 
battery portion 19 has been connected to the battery charge circuit 611. 
When the rechargeable battery portion 19 is placed in the socket well 223 
and thereby is connected to the battery charge circuit 611, the voltage 
stored on capacitor C1 drops as the charge is transferred to the battery 
pack or assembly 211. The decrease in voltage on capacitor C1 is sensed by 
the resistive divider network consisting of R2 and R11 and this voltage is 
transmitted to charge control integrated circuit IC1. In response, charge 
control integrated circuit IC1 outputs a signal to turn on switch SCR1 
thereby placing the battery charge circuit 611 in the fast charge mode. In 
the fast charge mode, switch SCR1 is on 100% or all of the time. For a 
completely discharged battery, the battery charge circuit 611 will remain 
in the fast charge mode for about 1 hour. 
Toward the end of the fast charge cycle, the temperature of the batteries 
213 in the battery pack or assembly 511 increases and the resistance value 
of R14 (as discussed above, a thermistor internal to the battery pack or 
assembly 511) decreases. The resistor divider network of resistors R12 and 
R13 establishes a voltage which is transferred to charge control 
integrated circuit IC1. When this voltage decreases by a predetermined 
amount, the fast charge mode is terminated by charge control integrated 
circuit IC1 and a top-off charge continues for approximately 30 minutes 
after the end of the fast charge mode. During the top-off charge mode, 
charge control integrated circuit IC1 triggers switch SCR1 so that it 
sequentially turns on and off in order to provide a pulsed current flow to 
charge the rechargeable battery portion 19. 
After the end of the top-off charge mode period, charge control integrated 
circuit IC1 reduces the frequency at which switch SCR1 is triggered during 
what is called a maintenance charge mode. Whenever current is flowing to 
the batteries 213, i.e., whenever the rechargeable battery portion 19 is 
in the socket well 223, indicator LED1 is lit to indicate that current is 
flowing to the battery pack or assembly 211. Also, whenever the battery 
charge circuit 261 is in the fast charge mode, indicator LED2 is lit. 
In use, when the clipper portion 17 and the rechargeable battery portion 19 
are assembled with the electrical terminals 131 of the clipper portion 17 
in electrical connection with the electrical terminals 171 of the 
rechargeable battery portion 19, the hair clipper 13 can be used by an 
operator in the normal fashion. After use, when the batteries 213 in the 
rechargeable battery portion 19 lose their charge, the rechargeable 
battery portion 19 of the assembled hair clipper 13 can be located in the 
socket well 223 of the battery charger 15 so as to electrically connect 
the electrical contacts 191 on the outer cylindrical surface 185 of the 
outer end portion 181 of the rechargeable battery portion 19 with the 
electrical contacts 231 located on the cylindrical wall 227 of the socket 
well 223 of the battery charger 15. 
In addition, should the batteries 213 in the battery assembly 211 become 
non-functional by reason of no longer being capable of receiving a further 
charge, the non-functional rechargeable battery portion 19 can be replaced 
by depressing the locking segment 67 of the locking ring 61 and by 
withdrawing the non-functioning battery portion 19 from the battery socket 
35 and by inserting a new rechargeable battery portion 19. The new 
rechargeable battery portion 19 can be inserted in the battery socket 35 
and electrical connection made between the electrical terminals 131 of the 
clipper portion 17 and the electrical terminals 171 of the rechargeable 
battery portion 19 in response to depression of the locking segment 67 of 
the locking ring 61 so as to align the bore of the locking or ring portion 
63 with the opening or aperture 55 in the flange 51 of the rear end 
portion 33 of the clipper portion 17. When such electrical connection is 
made, the locking ring 61 can be manually released so as to enable locking 
movement thereof, under the influence of the spring 64, into the locking 
groove 167 in the inner end portion 163 of the rechargeable battery 
portion 19. 
After a period of use, when the rechargeable battery portion 19 becomes 
spent or discharged, the spent or discharged rechargeable battery portion 
19 can be located in the socket well 223 of the battery charger 15 either 
when the spent or discharged rechargeable battery portion 19 is assembled 
with the clipper portion 17 or when the spent or discharged rechargeable 
battery portion 19 is disassembled from the clipper portion 17. Thus in 
use, when the spent or discharged rechargeable battery portion 19 requires 
recharging, the spent or discharged rechargeable battery portion 19 can be 
removed from the clipper portion 17 and located in the socket well 223 of 
the battery charger 15 for recharging, and another charged rechargeable 
battery portion 19 assembled with the clipper portion 17 so that the 
operator can continue to use the clipper portion 17 when the spent or 
discharged rechargeable battery portion 19 is being recharged. 
Various of the features are set forth in the following claims.