Focusing flashlight

An improved focusing flashlight is provided which includes a metallic cylinder having a collar at the front and adapted to receive a conducting cartridge and a seat insulator therein. The conducting cartridge has an internal thread formed in a centrally disposed hole and a flange extending around the perimeter of the hole, adapted to be received within a corresponding sleeve barrel extending from the seat insulator, around the perimeter of a centrally disposed hole. The internal threads of the conducting cartridge are adapted to threadedly engage a bulb.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a focusing flashlight, and more particularly to 
an improved bulb holder having simplified structure and assembly 
characteristics. 
2. Prior Art 
The conventional focusing flashlight, as shown in FIGS. 5, 6A and 6B, 
comprises a metal cylinder A, a head thimble B, a lamp socket C, an 
insulator D, a peanut bulb E and a cylinder cap F. The metal cylinder A 
has a hollow battery compartment and a collar A1 at the front end thereof 
having threads A2 formed on the outer surface for threaded connection with 
the head thimble B thereon. The head thimble B receives a curved female 
cone reflector B1 therein. The lamp socket C is an insulating flange, 
having a pair of curved grooves, positioned into the collar A1 of the 
cylinder A. A pair of apertures C1 are formed in the center portion of the 
lamp socket C for receiving a pair of corresponding conducting jack strips 
C2, C3. The strip C2 is bent outwardly to extend along the collar A1 while 
the strip C3 extends through the plug aperture C1 from the other end of 
the lamp socket C and is bent inwardly toward the center portion in order 
to make contact with the center pole of the battery. The insulator D is a 
disc having a pair of curved flaps D1 at the sides thereof and extend 
downwardly to be inserted into the corresponding grooves of the lamp 
socket C. The insulator D includes two apertures D2 corresponding to the 
apertures C1 for insertion of the two leads E1 of lamp E to extend 
therethrough. The cylinder cap F includes a conical spring F1 disposed at 
an inner portion thereof and threads formed on an outer portion thereof, 
for threaded engagement with the cylinder A. 
FIG. 6A shows a cross-sectional view of the conventional flashlight with 
batteries installed in the cylinder A and with the conical spring engaging 
and urging the battery towards the conducting strip C3. The reflector B1 
engages the insulator D to urge the lamp socket C inwardly, which 
disengages the conducting strip C2 from the collar A1 of the cylinder A to 
form an open circuit. On the other hand, when the head thimble B is 
displaced relative to the cylinder A, the reflector B1 will disengage from 
the insulator D, and the conducting strip C2 will engage with the collar 
A1 of the cylinder A to close the flashlight circuit. A further movement 
of the head thimble B relative to the cylinder A will change the focus of 
the beam. 
However, there are some shortcomings to be improved upon. For instance, the 
structure is complicated, and its assembly is more time consuming. 
Further, the fine leads of the lamp require careful installation to avoid 
having to discard parts that become damaged. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide an improved flashlight 
structure which is simple in structure, uses less parts and is 
conveniently assembled. 
A further object of the present invention is to provide an improved bulb 
holder structure, in which a new peanut bulb with a screw shell is used.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to FIG. 1, the present invention relates to a bulb holder and 
is composed of a conducting cartridge 1 and a seat insulator 2. The bulb 
holder is threaded to a flashlight which includes a cylinder 3, a head 
thimble 4, a cylinder cap 5 and a peanut bulb 6. The cylinder 3 has a 
collar 31 at one end and threads on the outer surface thereat for a 
threaded connection with the head thimble 4. The head thimble 4 has a 
reflector 41 secured therein. The cylinder cap 5 includes a spring 51 
fastened at a front end thereof, and threads which are formed on the outer 
surface adjacent the front end. The outer surface threads of the cap 5 
facilitate connection to the internal threads of the cylinder 3. The outer 
surface threads of the cylinder 3 facilitates connection with the head 
thimble 4. 
The conducting cartridge 1 is a metal stand (which is best made of copper) 
having a centrally formed threaded hole 12 and a flange 11 extending 
upwardly from one side of the cartridge 1 and surrounding the hole 12. A 
stop recess 111 is formed on the flange 11. 
The seat insulator 2 is a stand formed of a non-conductive material, best 
made of a plastic material, having a centrally formed hole 22. A sleeve 
barrel 21 extends from one side of the seat insulator 2 surrounding the 
hole 22, and a protuberance 221 extends from the inner wall of the hole 
21. The sleeve barrel 21 has a length greater than the thickness of the 
collar 31 of the cylinder 3 and an outer diameter that is smaller than the 
inner diameter of the cylinder 3. The hole 22 is dimensioned to receive 
the flange 11 therein, and the protuberance 221 will seat in the recess 
111. 
To assemble the present invention, the seat insulator 2 is first inserted 
into the cylinder 3 through the collar 31. Then, the flange 11 of the 
cartridge 1 is inserted into the hole 22 of the seat insulator 2, forming 
a bulb holder thereat. The bulb 6 is threadedly engaged within the 
threaded hole 11 of the conducting cartridge 1, as shown in FIG. 2. The 
batteries 7 are next placed into the battery compartment of the cylinder 3 
and the end portion is covered by threadedly connecting the cylinder cap 5 
to the cylinder 3, causing the spring 51 to engage the negative pole of 
the battery 7. The spring 51 urges the battery 7 forwardly, which urges 
the conducting cartridge 1 into engagement with the collar 31 of the 
cylinder 3, to form a closed circuit for the flashlight. Moreover, when 
threading the head thimble 4 to displace it rearwardly, the reflector 41 
will move rearwardly, which in turn urges the seat insulator 2 and 
conducting cartridge 1 rearwardly to disengage the cartridge 1 from 
contact with the collar 31 of the cylinder 3, thus, the circuit is placed 
into an open state, as shown in FIG. 3. 
In order to facilitate the assembly of the flashlight, cylinder 3, as shown 
in FIG. 4, is formed in two separate parts. One part is a battery 
compartment having threads 32 formed in an inner wall section adjacent a 
front end thereof. The other part is a cylinder adapter 8, which has a 
flange 81 which functions like that of the collar 31 of the first 
embodiment. Threads are formed adjacent the front portion of the adapter 8 
to be threadedly connected with the head thimble 4. Threads 82 are formed 
adjacent the rear portion of the adapter to be threadedly connected with 
the internal threads 32 of the cylinder 3. The cylinder adapter 8 allows 
the conducting cartridge 1 and the seat insulator 2 to be installed prior 
to the assembly of the cylinder 3 to the cylinder adapter 8.