Note: Descriptions are shown in the official language in which they were submitted.
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This invention L-elates to simple lightweight
fldshlights of a type commonly referred to as penlights, and
moce particu]arly to disposable penlights.
Penlights are used as a convenient and portable means
of providing an inspection light used by doctors, technicians,
and persons interested in various hobbies. Such products are
also sold as promotional items and can be incorporated into a
simple tool kit for emergency use.
The penlights generally resemble a pocket pen and have
a clip for attachment to the user's pocket. Altho~gh not
essential, it is common to manufacture the lights to have a life
equal to that expected of the energy source contained in the
light. Such disposable structures must therefore be simple to
manufacture in order to keep the cost to a minimum. The present
description will be directed mainly to a disposable penlight
which is exemplary of other structures within the scope of the
invention.
The requirements for a simple disposable penlight are
readily identified. A casing or housing contains an energy
source which is usually two conventional cells or batteries in
series and which have an electrical connection through a bulb
with an end terminal of one of the batteries. There is a
connection with the other battery case and a switch is provided
which is coupled in some way to the battery case and i9 capable
of closing the circuit between the case and the houslng so that
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the hulb will light. Commonly the switch is in the penlight
clip which is normally displaced from the housing and can be
brought into contact by squeezing the clip against the housing.
It will also be appreciated that the housing must be isolated
electrically from the clip or be non-conductive if the penlight
is to be secure from activation by contact with extraneous
conductive structures.
An example of a prior art structure i5 sho~n in U.S.
Patent No. 3,902,058 to Naylor et al. In this patent a
non-conductive housing is provided and the necessary electrical
connections are made internally. A somewhat complex clip
includes a resilient portion which has one end passing through
the casing to be in permanent electrical contact and the other
end is made to complete the circuit internally when the clip is
squeezed toward the casing. This structure has found some
commercial acceptance but suffers from disadvantages which are
typical of many prior art structures. For instance one
disadvantage lies in the assembly procedure. The clip must be
somehow engaged through an opening in the casing and after the
internal parts are positioned in the casing, the end of the
casing must be rolled or otherwise deformed to permanently
contain those parts. Such operations are both time consuming
and costly.
A second disadvanta~e is that the structure uses a lot
of small parts which are awkward to handle and which must be
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retained in the proper relationships until the casing is
deformed inwardly
By contrast, the present invention is intended to
overcome these disadvantages by providing a simple light which
has a minimum of parts and which can be assembled simply and
conveniently. Accordingly, in one of its aspects the light
includes a pocket clip assembly which is coupled electrically to
an energy source and bulb and which has an arm which is movable
by squeezing the arm to bring a distal end piece of the arm into
contact with the housing to energize the bulb. The clip
assembly includes a non-conductive fulcrum piece which is
attached to the arm in engagement wlth the housing and
intermediate the ends of the arm. This piece maintains the end
piece of the clip remote from the housing to prevent accidental
contact and to increase the force needed to bring the end piece
into contact with the housing.
This and other aspects of the invention will be better
understood with reference to the drawings, in which:
Fig. 1 is a side view of a preferred embodiment of a
penlight made according to the invention and showing a clip
assembly; ~ ;
Fig. 2 is an exploded perspectiye view of the parts
used to make the penlight; and
Fig. 3 is a sectional view on line 3-3 of Fig. 2 and
- showing the end structure of the penlight.
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Reference is first made to Fig. 1 which illustrates a
penlight indicated generally by the numecal 20. The penlight
includes a housing 22 made up of a casing 24 and an end cap 26.
These parts combine to contain the necessary elements which will
be described with reference to Fig, 2 as well as a clip assembly
28 having an arm 30 and end piece 32. The clip assembly is
electrically conductive but for an insulating fulcrum piece 34
coupled to the arm as will be described. As seen in ~ig. 1 the
fulcrum piece includes an enlarged end part 36 in contact with
the casing sufficient to maintain the end piece 32 of the arm 30
away from the casing 24. Consequently in the position shown in
Fig. 1, there is no electrical contact between the end piece 32
and the casing so that the light is not on. This will be better
understood following the description of Fig. 2 which will be
described with reference to the assembly procedure used to make
the penlight.
As seen in Fig. 2, the main element is the casing 24
which is made from tubular aluminum having an anodized outer
surface, one end of which is formed to retain an end insert 38
as shown in Fig. 3. This insert defines a central opening 40
and an end recess 42 forming a reflector for a bulb 44. The
casing is further worked to provide a small area 46 where the
insulating anodized Iayer is penetrated for electrical contact
by the end piece 32 of the clip assembly 28 as will be desaribed.
After the aasing has been completed by entering the end
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insert 38 and preparing the surface at ~6, the casing can be
stood in any suitable fixture which will provide support while
the parts are added. First the bulb 44 is dropped into the
casing to naturally take the position shown in Fig. 3. Next,
two long life batteries 48, 50 are dropped into the casing with
the projecting pole downwards so that the first pole will come
into engagement with the end contact of the bulb 44. These
batteries are provided with a synthetic plastic coating to
insulate the cylindrical sides of the batteries from the casing
24. The upper ends ~as shown~ of the batteries are of course
free of insulation to provide electrical contact.
Aftee the batteries have been dropped into the casing
24, an insulator 52 is engaged in the upper end of the casing.
This insulator hac a central opening 54 for receiving a simple
compressive coil spring 56, and is a firm engagement fit inside
the casing. Diametrically opposed slits 58 (one of which can be
seen) are provided to ensure that the insulator can be inserted
in the tube readily and an end collar 60 iæ provided to locate
the insulator on the end of the casing. After~this insulator
~20 has been pushed i;nto the~casing, the spring 56 is dropped
through the insulator and the clip assembly is added. As
previously described, this clip assembly includes an arm 30
having at one end an end piece 32. At its other end, the arm is
attached to a support 62 which defines an opening within a short
tubular extension 64 adapted to fit within an enlarged recess 66
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at the ~ per end oE the opening 54 in the insulator 52. It will
b~ appr~ci~ted that the tubular extension 64 effectively locates
the clip assembly relative to the i~sulator to maintain the clip
assembly in position while the end cap 26 is addedj and improves
electrical contact between the clip assembly and the end cap.
The end cap includes a cylindrical projection 68 shaped to be an
interference fit in the opening 54 within the insulator 52.
Consequently when the end cap is brought into the opening 54, it
is necessary to provide a downward force to engage the end cap.
This is provided by a suitable press without removing the
assembly from the fixture, which is of course shaped to accept
the downward force at the bottom end of the flashlight without
damaging the end structure of the flashlight.
Returning to the clip assembly, prior to the overall
assembly, a sub-assembly is conducted as previously mentioned.
The fulcrum piece 34 is shaped to fit within the end piece 32.
To facilitate this, the arm and end piece 32 of the clip
assembly are formed from a relatively thin metal sheet having a
rolled portion 70 providing a space indicated by the arrow to
receive a serrated tongue 72 of the fulcrum piece 34. These
serrations permit location behind the rolled piece 70 in any one
of the corrugations. Consequently the location of the end part
36 of the fulcrum piece 34 can be varied relative to the length
of the arm thereby providing a means of adjustment for the force
needed to squeeze the end piece 32 against the part 46 of the
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c~slng .
The electrical connections will next be explained with
reference to the preferred materials used in the penlight shown
in the drawings. As mentioned, the casing 24 is of aluminum
with the outer surface anodized. There is an electrical
connection from the batteries to this casing via the bulb 44 and
end insert 38. At the other end of the batteries, the spring 56
is separated from the casing by the insulator 52 which is
preferably of NYLON (registered trade mark). Eleatrical contact
is made with the spring by the projection 68 of the end cap 26
which is also of aluminum. This end cap is in contact with the
clip assembly so that the circuit from the pole formed by the
casing of the battery 50 passes via the spring to the end cap
and hence to the arm 30 and end piece 32. These parts are
insulated from the casing by the fulcrum piece 34. It will be
appreciated that because the casing is anodized, the fulcrum
piece could conceivably be of a conductive material. However it
is preferable to use a non-conductive material such as NYLON for
this piece in order to ensure that the insulation will not fail
as a result of wear in the anodized layer.
The electrical circuit is completed by p~essing the end
piece 32 of the arm 30 into engagement with the area 46 of the
casing 24. As mentioned, the force necessary to perform this
opetation can be varied by the location of the end part 36 of
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the fulcr~lm piece 34.
The batteries are preferably alkaline cells which have
a two year shelf life and do not require refrigeration. This is
a distinct advantage over prior art devices which have used
cells which require refrigeration to maintain a charge.
Variations to the structure are possible without
departing from the inventive concept. It would obviously be
possible to introduce an end cap which can be removed for
replacing the batteries. This could be done by threading the
cap or by other means. However the thrust of the present
invention is to provide a disposable structure having parts
which are inexpensive and which is capable of simple assembly to
minimize cost. Although other forms of insulation of the casing
could be used such as synthetic plastic coating, it should be
appreciated that this coating is necessary only to prevent
extraneous connection between the casing and the arm 30. If
such connection is not a problem, then the insulation would not
be necessary on the casing. These and other changes to the
structure are within the scope of the invention as described and
20~ ~la~med.
