U.S. patent number RE32,747 [Application Number 06/880,946] was granted by the patent office on 1988-09-13 for synthetic-resin and metallic layered housing for hand-held appliance.
This patent grant is currently assigned to Braun Aktiengesellschaft. Invention is credited to Roland Ullmann, Klaus Zimmermann.
United States Patent |
RE32,747 |
Ullmann , et al. |
September 13, 1988 |
Synthetic-resin and metallic layered housing for hand-held
appliance
Abstract
A housing has a wall constituted by a rigid metal plate formed
with an array of throughgoing perforations and by a flexible
synthetic-resin sheet overlying the inner face of the rigid wall
and having a multiplicity of projections each extending through a
respective perforation and beyond the outer surface of the rigid
plate. Futhermore the flexible sheet may be inwardly deflectable to
actuate a switch in the housing.
Inventors: |
Ullmann; Roland (Offenbach,
DE), Zimmermann; Klaus (Bremthal, DE) |
Assignee: |
Braun Aktiengesellschaft
(Kronberg, DE)
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Family
ID: |
6017710 |
Appl.
No.: |
06/880,946 |
Filed: |
June 25, 1986 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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743202 |
Jun 10, 1985 |
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938103 |
Aug 30, 1978 |
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Reissue of: |
338900 |
Jan 12, 1982 |
04388509 |
Jun 14, 1983 |
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Foreign Application Priority Data
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Aug 31, 1977 [DE] |
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2739137 |
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Current U.S.
Class: |
200/505;
16/110.1; 16/902; 200/293.1; 200/302.2; 200/52R; 200/61.85;
220/62.11; 428/138 |
Current CPC
Class: |
H01H
13/06 (20130101); H05K 5/068 (20130101); Y10T
16/44 (20150115); Y10T 428/24331 (20150115) |
Current International
Class: |
H01H
13/06 (20060101); H01H 13/04 (20060101); H05K
5/06 (20060101); H01H 009/04 () |
Field of
Search: |
;16/11R,114R,116R,DIG.12,DIG.18,DIG.24
;200/302.1,302.2,157,61.85-61.88,52R,329,340 ;220/415,453-454,461
;428/209,137,138 ;128/38,66 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1149273 |
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May 1963 |
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DE |
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1163706 |
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Feb 1964 |
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DE |
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1640444 |
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Mar 1966 |
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DE |
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2413016 |
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Apr 1974 |
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DE |
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2448627 |
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Oct 1974 |
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DE |
|
2558962 |
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Jan 1977 |
|
DE |
|
2846354 |
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May 1980 |
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DE |
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2284177 |
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Sep 1975 |
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FR |
|
539333 |
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Aug 1973 |
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CH |
|
1125973 |
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Sep 1968 |
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GB |
|
Primary Examiner: Recla; Henry J.
Assistant Examiner: Cusick; Ernest G.
Attorney, Agent or Firm: DeVellis; Raymond J.
Parent Case Text
.Iadd.This reissue application is a continuation, of Reissue
application Ser. No. 743,202, filed Jun. 10, 1985
abandoned..Iaddend.
This .Iadd.regular application .Iaddend.is a continuation of
.Iadd.patent .Iaddend.application Ser. No. 938,103, filed Aug. 30,
1978 now abandoned.
Claims
We claim:
1. In a switchable hand-held appliance, in combination:
a housing having a rigid wall formed with an array of perforations
extending between an inner and an outer face thereof;
an elastomeric nonmetallic sheet overlying said wall at said inner
face thereof and formed with a multiplicity of bosses each
penetrating a respective perforation and extending beyond said
outer face; and
switch means in said housing juxtaposed with a portion of said
sheet carrying some of said bosses, said portion being inwardly
deflectable away from said wall by finger pressure exerted upon
said some of said bosses for actuating said switch means, the
remainder of said sheet being fixed to said wall and preventing a
depression of all other bosses.
2. The combination defined in claim 1 wherein said some of said
bosses project farther beyond said outer face than to the other
bosses on the remainder of said sheet.
3. The combination defined in claim 2 wherein the projecting parts
of said some of said bosses progressively increase in length toward
the middle of said portion of said sheet.
4. The combination defined in claim 1, 2 or 3 wherein said wall
forms a recess adjacent said portion of said sheet, said some of
said bosses projecting from said recess.
5. The combination defined in claim 1 wherein said switch means
includes a metallic foil on a surface of a portion of said sheet
opposite said wall. .Iadd.
6. A two-layer housing for a hand-held appliance, said housing
defining an enclosed internal open space, said housing comprising a
substantially rigid housing wall, of a predetermined thickness,
having an inner face and an outer face with an array of
perforations extending between said faces, a continuous sheet of
synthetic resin material, at least a portion of which is rigidly
bonded to the inner face of said housing wall, said housing wall
being continuous between said perforations, said sheet having a
multiplicity of individual upstanding bosses, each said boss having
a predetermined diameter and each said boss extending through a
respective perforation and projecting one-quarter to three-quarters
the thickness of said housing wall beyond said outer face and said
bosses being spaced at most about three times the diameter of said
bosses from each other, each said upstanding boss of said
continuous sheet of synthetic resin material located on the portion
of said sheet which is rigidly bonded to the inner face of said
housing wall forming a tight and sealed connection with its
respective perforation to hold said sheet and said bosses in
position thereby rendering said bosses non-displaceable with repect
to said respective perforations of said housing wall, and to
prevent moisture from entering the internal open face of said
housing..Iaddend. .Iadd.7. The housing as defined in claim 6
wherein each said boss includes a rounded tip projecting beyond
said outer face of said wall, and wherein each said individual
upstanding boss is generally cylindrical..Iaddend.
Description
FIELD OF THE INVENTION
The present invention relates to a housing for a hand-held
appliance such as an electric shaver, electric toothbrush, camera,
or even calculator.
BACKGROUND OF THE INVENTION
It is known to cast the housing of a hand-held appliance of the
type listed above from metal to make a very solid and strong
housing, or to deep draw or stamp sheet metal to make a rigid metal
housing. In order to dress up the appearance of such a housing,
which frequently tends to scratch readily, it is known to laminate
attractive and normally textured synthetic-resin sheets over the
metal structure.
Such housings are frequently found objectionable because they do
not allow sweat or, in the case of an electric toothbrush or the
like, other liquids to dissipate. Such liquids also often lead to
corrosion and an unattractive appearance.
Another difficulty is that it is almost invariably necessary to
provide at least one externally operable switch in such a housing.
In a hand-held calculator in particular it is necessary to provide
an entire keyboard. Forming a tight seal around the operating
button of such a switch or of such switches is an onerous task that
normally increases production costs considerably while still
yielding unsatisfactory results. Any moisture entering around the
switch-actuating member can lead quickly to component failure, and
can even in some instances present a real danger of a serious
electrical shock to the user.
OBJECTS OF THE INVENTION
It is therefore an object of the instant invention to provide an
improved housing for a hand-held appliance of the above-described
and listed types.
Another object is the provision of such a housing which is rugged
yet agreeable to the touch, and wherein it is possible to provide
externally operable switches which are adequately sealed.
SUMMARY OF THE INVENTION
These objects are attained according to the instant invention in a
housing having a two-layer wall that has a substantially rigid and
normally metallic layer formed with an array of perforations and an
elastomeric or flexible and normally nonmetallic layer formed with
a multiplicity of bosses each of which engages in and projects
through a respective one of the perforations. Such a structure is
generally described in our copending and commonly assigned patent
application Ser. No. 901,703 filed May 1, 1978, now U.S. Pat. No.
4,197,968, whose entire disclosure is herewith incorporated in the
present application. In the housing of the instant invention,
however contrary to the disclosure of our prior patent, the
flexible bossed sheet lies against the inner face of the rigid
housing and its bosses project beyond the outer face thereof, so
that the tips or outer ends of the bosses are presented on the
outside and constitute an agreeable and attractice surface for the
user to hold. In fact such a two-part housing does not have the
so-called "sweaty" feel of the standard all-metal or all-plastic
housings, as air spaces are left between the fingertips of the user
and the housing itself.
It is possible according to the instant invention to provide a
switch in such a housing simply by allowing a portion of the inner
sheet to be inwardly deflectable, and by providing a push-type
switch at this inwardly deflectable region. To indicate the
location of the switch, the bosses at the switch location are made
longer than elsewhere, so as to provide a bump on the outer surface
of the housing. In such an arrangement the sheet is secured around
the switch location to the inner face of the outer metal plate
constituting the housing wall, the only depressible bosses lying in
the vicinity of the switch location where the sheet is not fixed to
the metal plate.
According to yet another feature of the invention such a switch can
be constituted simply by providing an electrically conductive
element or foil on the inner surface of the inner flexible sheet,
and a pair of contacts normally spaced slightly inwardly of this
conductive region. Inward depression of the sheet at these contacts
will bridge the contacts with the conductive surface and close the
circuit. A particular advantage of the instant invention is that
the housing can be completely watertight at the switch, as the
inner sheet can be continuous so that even if some water or other
liquid makes its way through any of the perforations around the
respective boss, separation of the inner flexible sheet is
impossible. In fact it is possible to provide an entire keyboard in
this manner which can be fully watertight, and even gastight. The
switch or switches inside the housing, as well as other structure,
are therefore hermetically sealed in.
BRIEF DESCRIPTION OF THE DRAWING
The above and other features of our invention will now be described
in detail with reference to the accompanying drawing in which:
FIGS. 1 and 2 are cross sections through portions of a housing
according to this invention;
FIG. 3 is a section through the housing of FIG. 1 in another
operative position; .[.and.].
FIG. 4 is a cross section through a portion of another housing
according to this invention.[...]. .Iadd.and.Iaddend.
.Iadd.FIG. 5 is a perspective view, partial in section, of a dry
shaver, in accordance with this invention..Iaddend.
SPECIFIC DESCRIPTION
As shown in FIGS. 1 and 3 a housing according to this invention has
an outer aluminum wall constituted by a plate 1 having an inner
face 2 and an outer face 6 and formed with a substantially uniform
array of throughgoing cylindrical perforations 5. An elastomeric
synthetic-resin sheet 3 is secured to this plate 1 and has an outer
face 15 bearing on the inner face 2, an inner face 7, and a
multiplicity of cylindrical and rounded bosses or projections 4
each extending through a respective hole 5 and projecting by a
distance a beyond the face 6. The distance a is equal to between
one-quarter and three-quarters of the thickness T of the plate 1 as
mentioned in our above-cited patent. The rounded tips of these
projections 4 are normally all that contacts the fingers of the
user, as the distance D between adjacent projections is equal to at
most three times the diameter d of the projections 4 and of the
holes 5, which in turn is generally equal to T. The exposed metal
between the projections 4 nonetheless creates a very attractive
appearance, and the projections 4 will protect it from being
scratched.
FIGS. 1 and 3 further show how the inner face 7 of the flexible
sheet 3 can be provided with a conductive, here copper, foil 8
engageable with a pair of contacts 9 and 10 carried on a mount 11
fixed in the housing. The elements 8-10 therefore form a very
simple switch which is closed when the bosses 4 opposite the foil 8
are deflected inwardly as shown in FIG. 3 so that foil 8 bridges
the contacts 9 and 10.
To this end the sheet 3 is not connected to the face 2 in the
region A at the switch, but is bonded thereto at regions B and C
flanking this region A by means of a glue bond 23; thus, the bosses
4 in these latter two regions cannot be depressed into plate 1.
Furthermore the outer edge portions 21 of the sheet 3 are formed as
a flexible and relatively thin cut 22 for securing of this housing
wall in a housing according to this invention while forming a
hermetic seal. The joints 16 around the projections 4 in region B
and C are very tight and may be sealed.
FIG. 2 shows an arrangement substantially identical to that of
FIGS. 1 and 3, except that some of the projections 4 are replaced
by projections 12-14 which are extended by a distance b greater
than the distance a beyond the face 6. Such extra-length
projections 12-14 serve to indicate the location of a switch,
forming a bump easily seen and felt by the user. The projections
are progressively longer toward the center of the bump thus
formed.
FIG. 4 shows another arrangement wherein the metallic plate 1 is
formed with a recess 17 and wherein the sheet 3 overlying its inner
face has projections 19 of greater length at this recess 17 than
its nondepressible projections 20 surronding the recess 17.
Furthermore the two layers 1 and 3 are not bonded together in the
region E of the recess 17 as in FIG. 3. A standard push-button
switch 18 is provided inside the housing adjacent the inner face of
the sheet 3 for actuation when the sheet is elastically deformed
inwardly normally to the housing wall.
.Iadd.FIG. 5 is a perspective view of a dry shaver having the
two-layer housing of FIG. 1 and defining an enclosed internal open
space 24.
* * * * *