Twist on/off and adjustable focus flashlight

The present invention is directed to an on/off switch for a flashlight having a reflector secured against axial motion. The reflector has a central opening. The flashlight includes a bulb with a base having an outer cylindrical electrical terminal. The bulb extends through the central opening of the reflector. The switch includes a bulb holder, with the bulb secured in and moving with the bulb holder. The switch also includes an electrical contact disposed in the flashlight so as to be adjacent and biased away from the cylindrical electrical terminal of the bulb. The switch also includes a ring rotatably disposed in the flashlight. The ring is mechanically linked to the bulb holder and includes an element disposed adjacent the electrical contact. Rotation of the ring causes the bulb holder and thus the bulb to move axially relative to the reflector due to the mechanical link and simultaneously causes the element to force the electrical contact against the bias and into contact with the cylindrical electrical terminal of the bulb.

BACKGROUND OF THE INVENTION 
1. Field of Invention 
This invention is directed to a flashlight including an on/off mechanism 
which also serves to control the focus of the flashlight. 
2. The Prior Art 
Flashlights including switches which control both the on/off functioning 
and the focusing are known in the art. Such flashlights include a head 
which is rotatable relative to the flashlight barrel. A reflector is 
secured within the head. With the flashlight initially off, the head is 
rotated through a predetermined arc to first switch the flashlight on. 
Additional rotation causes relative axial movement between the bulb and 
the reflector to control the focusing from either a narrow beam with the 
bulb in a highest position relative to the reflector or a wider beam with 
the bulb in the lowest position relative to the reflector. 
An example of a prior flashlight which incorporates both on/off functioning 
and focusing is shown in German Patent No. 1,039,631 which discloses a 
bulb socket with radially extending pins which project through helical 
grooves of a fixed guide cylinder and fit within an axial groove of a 
rotatable ring. The ring is integral with the bezel. Rotation of the bezel 
and ring forces both rotational and axial displacement of the socket and 
the bulb due to engagement of the pins in both the axial grooves of the 
ring and the helical grooves of the guide cylinder. The bulb moves axially 
relative to both a contact linked to the battery terminal and the 
reflector, thereby allowing both on/off control and focusing. 
SUMMARY OF THE INVENTION 
The present invention is directed to an on/off switch for a flashlight 
having a reflector secured against axial motion. The reflector has a 
central opening. The flashlight includes a bulb with a base having an 
outer cylindrical electrical terminal. The bulb extends through the 
central opening of the reflector. The switch includes a bulb holder, with 
the bulb secured in and moving with the bulb holder. The switch also 
includes an electrical contact disposed in the flashlight so as to be 
adjacent and biased away from the cylindrical electrical terminal of the 
bulb. The switch also includes a ring rotatably disposed in the 
flashlight. The ring is mechanically linked to the bulb holder and 
includes an element disposed adjacent the electrical contact. Rotation of 
the ring causes the bulb holder and thus the bulb to move axially relative 
to the reflector due to the mechanical link and simultaneously causes the 
element to force the electrical contact against the bias and into contact 
with the cylindrical electrical terminal of the bulb.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to FIGS. 1 and 2, a flashlight according to the present 
invention is shown. The flashlight is shown mounted on rechargeable 
battery 1 as shown and described in U.S. Pat. No. 5,489,484, hereby 
incorporated by reference. Battery 1 includes cup-shaped positive terminal 
1a at the center of the forward open end, and metallic outer casing 1b 
which defines the open forward end of the battery and serves as the 
negative terminal. The flashlight includes housing assembly 2, turning 
ring 5, head 7 and bulbholder assembly 8. Housing assembly 2 is disposed 
directly on the forward end of battery 1. Turning ring 5 is rotatably 
secured on the forward open end of housing assembly 2. Bulbholder 8 is 
supported within turning ring 5. Head 7 is secured upon turning ring 5 by 
screw-threading and is rotatable jointly with ring 5. 
The flashlight utilizes conventional flashlight bulb 100 including a bulb 
base defined by outer cylindrical metallic terminal 102 having integral 
flange 101. Central terminal 103 extends from a bottom tip of the base and 
is surrounded by an insulator to isolate it from terminal 102. 
With further reference to FIGS. 5, 6 and 8-8B, housing assembly 2 further 
includes housing 20 including rearward cylindrical peripheral wall 23 
having a rearward opening into which the forward open end of battery 1 
fits. The forward end of the opening is defined by inner surface 24 which 
is contacted by the forward open end of battery 1. Central metallic rivet 
22 is secured to and extends rearwardly from inner surface 24 and is 
received by positive cup-shaped terminal 1a. Two peripherally disposed and 
bent tab-shaped terminals 21 also are secured to and extend rearwardly 
from inner surface 24 and receive outer metallic casing 1b of battery 1. 
Rivet 22 and tab-shaped terminals 21 include nubs which extend through 
openings in inner surface 24 to allow the circuit to be completed from the 
battery terminals to the opposite side of inner surface 24. 
Forward of inner surface 24, housing 20 includes forwardly projecting 
cup-like flange 26 which has opening 26a formed in the periphery for a 
predefined arcuate and axial extent. Bulb spring 27 is disposed in flange 
26 and is linked in electrical contact with the forward nub of rivet 22. 
Bulb spring 27 forms a positive contact for central terminal 103 of bulb 
100. The extending nub of one of tab-shaped terminals 21 is linked in 
electrical contact with arcuate contact plate 28 which is disposed about 
flange 26. With reference to FIG. 2A, terminal end portion 28a of contact 
plate 28 is hook-shaped and is located at the position of opening 26a, 
adjacent to bulb outer terminal 102. Contact plate 28 is biased radially 
outwardly such that terminal end portion 28a is out of contact with 
terminal 102. Contact plate 28 also includes radially outward projecting 
protuberance 28b disposed between terminal end portion 28a and the 
location where plate 28 is linked to the nub of tab terminal 21. 
Housing 20 also includes two vertical posts 30a and 30b disposed outwardly 
of flange 26 and extending upwardly from inner surface 24. Post 30a is 
disposed adjacent opening 26a and outwardly of hook portion 28a. Post 30b 
is disposed generally opposite post 30a. Vertical wall 29 also extends 
upwardly from inner surface 24, and is integral with and extends outwardly 
from flange 26. Housing 20 includes forward cylinder wall portion 25 
flaring outwardly from wall 23, and extending forward of flange 26. The 
forward end of wall portion 25 is open. Arcuate undercut tabs 25a extend 
inwardly at opposite locations along the forward periphery of wall portion 
25. 
With reference to FIGS. 10-10c, turning ring 5 includes forward cylindrical 
wall 52 having outer screw-threading 52a. Rearward of wall 52, ring 5 
includes integral larger diameter outer collar 54 and smaller diameter 
outer collar 55 which are axially spaced from each other so as to define 
an axial surface therebetween. Two spaced arcuate recesses 56 are formed 
on opposite sides of this axial surface. Ring 5 snaps into housing 20 with 
inward tabs 25a fitting within recesses 56. Recesses 56 extend for a 
greater arcuate extent than tabs 25a to allow limited rotation of turning 
ring 5 relative to housing 20. 
Ring 5 includes inner ledge 63 defining central opening 64. Two oppositely 
disposed pins 62 protrude into opening 54 from ledge 63. Arcuate rib 58 
extends downwardly from ledge 63 on one side of central opening 64. Rib 58 
has end surfaces 58a and 58b and includes lower horizontal portion 59 
extending inwardly beneath opening 64. Horizontal portion 59 further 
includes inner vertical wall 60 which extends for a limited arcuate extent 
and terminates at end 58b. Though not shown, a second arcuate rib may 
extend downwardly along the opposite side of opening 64. Though not 
visible in FIGS. 2 and 3, rib 58 also is shown in the cross-sectional view 
of FIG. 4. 
As shown in FIG. 2A, when turning ring 5 is snapped onto housing 20, rib 58 
is disposed between vertical posts 30a and 30b. Inner vertical wall 60 is 
disposed radially outwardly of contact plate 28. The rotation of turning 
ring 5 relative to housing 20 is limited in either direction by contact of 
circumferential end surfaces 58a and 58b of rib 58 with vertical posts 30a 
and 30b. At one limit of rotation, one circumferential end surface 58a 
contacts vertical post 30b. At this position, vertical inner wall 60 
terminates at a position which is closer to vertical post 30a than 
protuberance 28a, that is, inner wall 60 is not adjacent to the 
protuberance. However, rotation of ring 5 causes vertical inner wall 60 to 
move adjacent and past protuberance 28a, until the inner wall contacts 
post 30b. 
With reference to FIGS. 7-7c and 9a-b, bulb holder 8 is disclosed. Bulb 
holder 8 includes bulb holder base 80 and retainer or locking ring 90. 
Base 80 includes a surface portion defining a central opening 84 having a 
radius which is slightly larger than bulb outer contact 102, but less than 
the radius of bulb flange 101. Base 80 also includes two raised tabs 82 at 
opposite locations of the surface portion. Tabs 82 include outward 
overhanging portions 82a at the upper ends. 
Locking ring 90 includes central opening 96 of approximately the same 
radius as central opening 84, and two arcuate slots 92 disposed at 
opposite circumferential locations. Arcuate slots 92 have a substantially 
constant inner diameter, and a stepped outer diameter such that a portion 
of the slots have a reduced radial thickness. Ring 90 also includes two 
fins 94 extending upwardly from the upper surface at opposite 
circumferential locations which are approximately 90.degree. from the 
locations of the slots. 
Bulb 100 is secured in holder 8 by inserting the bulb base through opening 
84 of base 80, with bulb flange 101 resting on the surface. Ring 90 is 
disposed upon base 80, with the bulb lamp fitting within opening 96, and 
raised tabs 82 including overhanging portions 82a fitting within the 
larger radial thickness portions of arcuate slots 92. Ring 90 is twisted 
relative to base 80 by grasping fins 94, such that tabs 82 move within the 
reduced radial thickness portions of slots 92. Overhanging portions 82a 
are disposed above the surface of ring 90 to secure the ring on the base. 
Ring 90 fits over bulb flange 101, thereby securing bulb 100 in the axial 
direction within holder 8. 
Base 80 includes outer collar 81 extending downwardly from the surface 
portion and having a radius approximately equal to the radius of opening 
64 in turning ring 5. Outer collar 81 includes helical cam slots 85 formed 
at opposite locations. Slots 85 begin at openings in the lowermost surface 
of collar 81, and extend laterally upwardly along the collar, terminating 
at the surface portion of base 80. Slots 85 cause the wall portions of 
collar 81 to have flexibility in the radial direction. The ends of 
flexible wall portions include outward tabs 81a. Bulb holder base 80 also 
includes inner collar 83 disposed slightly outwardly of central opening 
84. Inner collar 83 includes vertical slot 87 extending to the surface 
portion of the base. Base 8 is secured in turning ring 5 by disposing 
outer collar 81 through opening 64. The flexible walls are pressed 
inwardly to pass collar 81 through the opening. As shown in phantom in 
FIG. 7c, pins 62 extend within helical cam openings 85. Tabs 81a of the 
wall portions extend below ledge 63 of ring 5. 
When turning ring 5 is disposed on housing 20 as described above, vertical 
wall 29 extending from inner surface 24 of the housing fits within 
vertical opening 87 of base 80 thereby precluding rotation of base 80 and 
holder 8. Therefore, rotation of turning ring 5 causes pins 62 to move 
laterally within helical cam slots 85. Since the vertical position of pins 
62 is fixed, base 80 must move vertically (axially) up or down to 
accommodate rotation of pins 62. Retainer ring 90 and bulb 100 retained 
thereby move with base 80. Accordingly, rotation of ring 5 relative to 
housing 20 causes axially upward or downward movement of bulb 100. 
With reference to FIGS. 4 and 5, head section 7 includes screw-threaded 
bezel 70, lens 74 and reflector 72. Bezel 70 includes inner recesses 70a 
and reflector 72 includes tab 72a about the periphery. By insertion of tab 
72a in recesses 70a, bezel 70, lens 74 and reflector are secured together, 
with the reflector held stationary in the vertical direction. This 
combined assembly is fixedly secured to ring 5 by the screw-threading. 
After bezel 70 is secured to ring 5 by rotating the bezel relative to the 
ring, further rotation of bezel 70 causes joint rotation of ring 5. 
Therefore rotation of bezel 70 causes axial movement of bulb 100, as well 
as rotational movement of rib 58. Bulb fits within a central opening of 
reflector 72, and moves axially relative thereto. 
In operation, as shown in FIGS. 2 and 2A, with the flashlight initially 
off, pins 62 are located near the open ends of helical grooves 85, which 
is the lowest-most point in the vertical direction. Bulb holder 8 is in 
the uppermost position relative to turning ring 5, and bulb 100 is in the 
uppermost position relative to reflector 72. Bulb spring 27 is in an 
extended state so as to make contact with central contact 103 of bulb 100. 
End 58a of rib 58 abuts vertical post 30b, and vertical wall 60 of rib 58 
is disposed out of contact with protuberance 28b. Accordingly, hook end 
portion 28a of contact 28 is biased radially outwardly relative to opening 
26a of flange 26, and therefore is not in contact with outer terminal 102 
of bulb 100. The circuit is open, and bulb 100 is not illuminated. 
With reference to FIG. 2B, bezel 70 and turning ring 5 are then rotated 
relative to housing 20. The initial rotation causes inner vertical wall 60 
of rib 58 to slide over protuberance 28b, thereby pushing protuberance 28b 
and hook end 28a of contact 28 radially inwardly. Hook end 28a moves 
inwardly relative to opening 26a of flange 26 and contacts outer terminal 
102 of bulb 100 to complete the circuit and illuminate the bulb. 
Simultaneously, pins 62 begin to travel along helical groove 85 of base 
80, forcing base 80 to begin traveling downwardly. Thus, bulb 100 begins 
to move downwardly relative to reflector 72. At the time of initial 
illumination, bulb 100 is at the maximum spacing above reflector 72. 
Accordingly, the light is focused in a narrow beam or spotlight pattern. 
With reference to FIGS. 3 and 3A, bezel 70 and turning ring 5 may be 
further rotated until end 58b of rib 58 contacts opposite vertical post 
30a. Throughout the extent of this further rotation, vertical wall 60 of 
rib 58 is maintained in contact with protuberance 28a and bulb 100 remains 
illuminated. However, the continued movement of pins 62 in helical cam 
grooves 85 causes continued downward movement of bulb holder 8 and bulb 
100. As bulb 100 moves closer to reflector 72, the reflected light is 
dispersed to a wider, unfocussed beam. Throughout, the extent of axial 
movement, bulb spring 27 remains in contact with bulb 100. 
The circuit may be opened by rotation of bezel 70 and ring 5 in the 
opposite direction. Further rotation, which is opposite of the direction 
in which bezel 70 was rotated to secure it on ring 5, will cause bezel 70 
to be unscrewed from ring 5. Bezel 70 may be removed in this manner to 
allow access to retainer ring 90 of bulb holder 8. Retainer ring 90 may be 
rotated relative to base 80 by grasping fins 94 until the tabs 82 align 
with the thicker portions of slots 92 and removed from base 80, allowing 
the bulb to be replaced. 
In the figures, housing wall 21 is shown as truncated, such that the user 
would hold battery 1 to use the flashlight. Of course, the present 
invention also is applicable to flashlights in which the wall extends 
further along the battery so as to more completely surround-the battery, 
and if desired, entirely encase the battery.