US3851126A

US3851126A - Flashlight switch

Info

Publication number: US3851126A
Application number: US00399756A
Authority: US
Inventors: D Keller
Original assignee: PRO LIGHT Inc
Current assignee: ITT Corp; PRO LIGHT Inc
Priority date: 1973-09-21
Filing date: 1973-09-21
Publication date: 1974-11-26
Anticipated expiration: 1991-11-26

Abstract

A flashlight switch combining reliable, positive-action operation with ease of assembly and disassembly. Two terminals are formed integral with the flashlight body and two contact strips are secured to the terminals by screws which also serve to secure a switch cover to the body. A switch button protrudes through an opening in the cover and the lower side of the button has a camming surface which cooperates with one of the contact strips to close the switch in a positive manner. The switch has an off position, an intermediate non-lock position in which the contacts may be momentarily operated upon depression of the switch button and a lock-on position in which the contacts are held in fixed engagement by a cam projection on the switch button. The cam operated movable contact is configured in such manner so that two switch operative modes are possible.

Description

United States Patent 1191 Keller Nov. 26, 1974 FLASHLIGHT SWITCH Primary Examiner.la'mes R. Scott [75] Inventor. Donald A. Keller, San Dimas, Calif. y, g or Firm Fulwider Patton Rieber, [73] Assignee: Pro-Light Inc., Los Angeles, Calif. L & Utecht 22] Filed: Sept. 21, 1973 21 Appl. No.2 399,756 [571 ABSTRACT A flashlight switch combining reliable, positive-action 52 us. (:1 200/60, 200/302, 200/329, operetion with ease assembly? disassemblye TWO 240/1066 termmals are formed 1ntegral w1th the flashhght body 51 1111.131 F21v 23/04, HOlh 9/02 and two CPmact Strips are Secured to F terminals by [58] Field of Search H zoo/6 R 6 B, 6 BB 6 BA, screws wh1ch also serve to secure a switch cover to the ZOO/6 C, 16 R 60, 237450, 302 329; body. A switch button protrudes through an opening 240/84, 112 R 1066 in the cover and the lower side of the button has a camming surface which cooperates with one of the 56] References Cited i intact strlipfi to close fthe switch in a positivg manner.

e swltc as an o os1t1on, an lnterme late non- UNITED STATES PATENTS lock position in which tEe contacts may be momentarl,902,590 3/1933 Shannon 200/60 Operated upon depression 0f the Switch button and sgy 'g a lock-on position in which the contacts are held in 2 466414 4/1949 0115 311111 11, IIT200 329 x fixed engagement by a cam projection on h Switch 2:477:5l6 7/1949 Haas 200/60 bum) The cam operated movable Contact Config' 2599295 6/1952 Thomas 200,60 ,ured in such manner so that two switch operative 3,162,376 12/1964 Furuya ..1 200/60 x modes are Possible- 3,221,115 I 1/1965 Feher, Jr 1 200/250 X 3,226,502 12/1965 SChOIZ 200/60 4 Clalms 6 Drawmg Flglres FLASHLIGHT SWITCH BACKGROUND OF THE INVENTION This invention relates to flashlight switches, and in particular to switches for flashlights made for the most part from molded plastics.

Since a flashlight switch establishes an electrical connection between one or more batteries and a light bulb, it is essential for such a switch to provide positive and reliable operation over a long period of repeated usage. It is also highly desirable for a flashlight switch to combine this reliability of operation with: ease of assembly and replacement of components, rugged and weatherresistant construction, and ability to function either as a positive action switch, holding in an on position, or

as a momentary switch, remaining on only while the switch is depressed.

SUMMARY OF THE INVENTION The present invention resides in an improved flashlight switch which combines the advantages of reliability, positive action, ease of assembly and replacement of components, and rugged, weather-resistant construction. The switch includes a fixed contact strip and a movable contact strip, each connected to a terminal, and a sliding switch button fitted to protrude through an opening in a cover enclosing the contactstrips, and movable to cam the movable contact strip into contact with the fixed contact strip, thereby closing the switch.

In the preferred embodiment of the invention, the switch is fitted to the outside of a molded flashlight body, and the terminals are threaded metal inserts in the wall of the body. Conducting strips are connected to the terminals on the inside of the wall, and the contact strips and the cover are secured to the outside of the wall by screws engaged with the threaded terminals. The threaded portions of these screws are coated with an insulating material so that there is no possibility of switching on the flashlight by inadvertent electrical contact between the heads of the screws.

The cover is made from a durable, molded plastic, and, together with the sliding switch button fitted snugly into the opening of thecover, effectively protects the switch against the weather and against rough handling. Furthermore, the cover is easily removable and replaceable should any of the components of the switch require replacement.

The switch may be operated either by sliding the button from an off position to an on position and thus holding the switch on by the spring-like action of the movable contact strip, or by sliding the button to a central position and then pressing it against the movable contact strip to close the switch momentarily until the button is released.

Other aspects and advantages of the invention will become apparent from the following detailed description, taking in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing the components of the switch and including a diagrammatical representation of the electrical circuit of the flashlight;

FIG. 4 is a side elevational view of the assembled switch in the on position, shown in cross-section;

FIG. 5 is a sectional view of the assembled switch taken substantially along the line 5-5 of FIG. 2; and

FIG. 6 is a view of the switch button taken substantially along the line 66 of FIG. 1.

DETAILED DESCRIPTION As shown in the drawings for purposes of illustration, the invention is embodied in a flashlight switch. Typically, the switch, indicated generally by the reference number 10, is mounted on the flashlight body 11, and completes an electrical circuit connecting a bulb 12 and one or more batteries 13. Broadly, the switch provides the means for electrically connecting and disconnecting a forward terminal 14 and a rear terminal 15, in response to the movement of a switch button 17.

In accordance with the present invention, the switch 10 comprises a fixed contact strip 18 connected to the forward terminal 14, a movable contact strip 19 connected to the rear terminal 15, a cover 20 secured to the body 11 to surround the contact strips and protect the entire switch from the elements and from rough handling, and the sliding switch button 17 fitted beneath the cover to protrude through an elongated opening 21 in the cover. The button 17 has a camming surface 22 on its underside which cooperates with the movable contact strip 19 to move it into contact with the fixed contact strip 18. Besides providing a rugged, reliable, positive-action switch, the invention has the advantage of being easily disassembled for replacement of parts.

More specifically, in the preferred embodiment the flashlight body 11 includes a hollow tube molded from a tough plastic material, and the terminals 14 and 15 are small metal inserts formed integral with the cylinder wall and extending through it without protruding. Each terminals has a threaded hole through it and is permanently connected to one of two conducting

strips

23 and 24 running along the inside surface of the tube as shown, or formed integral with the tube wall.

The fixed contact strip 18 is a relatively short flat metal strip with a hole 25 close to its forward end, by which the element is held in contact with the forward terminal 14 by the cover 21 and a screw 27, which also serves to secure the cover to the flashlight body. Similarly, the movable contact stip 19 is also a flat metal strip with a hole 28 close to its rear end, by which it is held in contact with the rear terminal 15 by the cover and a second screw 29. The

contact strips

18 and 19, while flat in cross-section, have certain distinctive contours over their length, as will be subsequently described in some detail. The

contact strips

18 and 19 are positioned in substantial alignment between the two terminals, and although neither is long enough to span the distance between the terminals, the movable contact strip 19 is the longer of the two and partly overlaps the fixed contact strip 18.

The switch cover 20 is a single-piece plastic molding having side walls 30, a generally oval-shaped, flat top wall 31 and a flange-like portion 32 surrounding the side walls. (See FIG. 1. The flange-like portion 32 is curved to fit snugly against the curved wall of the flashlight body 11 and has two holes 33 to receive the

screws

27 and 29 for assembly of the switch. When fitted to the flashlightbody 11, the cover 20 forms an elongated cavity of varying depth, in which the

contact strips

18 and 19 and the switch button 17.are contained.

The elongated opening 21 in the cover 20 is centrally located in the top wall 31 of the cover. On the inside of this top wall 31, close to the sides of the opening 21, are two parallel guide rails 34 formed integral with the cover 20 and extending for substantially the entire length of the top wall. The rails slope slightly downward toward the rear end of the cover 20 in which the fixed contact strip 18 is located. That is, the rails project further from the top wall 31 at the rear end of the cover 20.

The switch button 17 is also a single-piece plastic molding. It is generally rectangular in shape, with upwardly facing grooves 35 (FIG. along its sides to engage the depending guide rails 34 in the cover 20. The button 17 has a flat upper surface which is normally held securely against the underface of the top wall 31 of the cover 20 to completely fill the opening 21. A raised, round portion 37 in the center of the upper surface of the button 17 protrudes through the opening 21 and has a grooved, convex upper end to provide a positive grip for operation by a persons thumb or finger. The switch button 17 has a lower surface defined by two raised longitudinal ridges 38 along its sides, and a substantially flat portion between said ridges, forming the camming surface 22. The camming surface 22 has three raised, half-

round ridges

39, 40 and 41 across its width, a forward ridge 39 close to the forward end, a rearward ridge 40 close to the rearward end of the camming surface, and a central ridge 41 located slightly rearward of the midpoint between the forward and rearward ridges. Depending from the longitudinal ridges 38 are two forwardly located lugs 42 and two rearwardly located lugs 43, the four lugs extending downwardly from the four comers of the switch button 17 substantially beyond the half-

round ridges

39, 40 and 41.

The switch is assembled with the rearward end of the camming surface 22 of the button 17 adjacent the rear terminal and overlying the movable contact strip 19. The movable contact strip 19 viewed in elevation has a forwardly extending curved portion 44, convex when viewed from above, including two adjacently located convex humps 45 (rearward) and 46 (forward) near the midpoint of the strip. When the switch is in its off position, the switch button 17 is positioned as close as possible to the rear terminal 15 to which the movable contact strip 19 is connected, the

lugs

42 and 43 touch the body 11 to prevent closing of the switch contacts, and the switch button is held in position by action of the

humps

45 and 46 against the rearward ridge 40 and the central ridge 41, respectively. The rearward ridge 40 and the central ridge 41 thus act to resist movement of the switch button 17 and hold the switch positively in the off" position.

As the switch button 17 is moved to the central position, the rearward and

central ridges

40 and 41 slide over the

convex humps

45 and 46, respectively, and come to rest straddling the forward hump 46. In this position, the rearward lugs 43 are still touching the body 11, but the forward lugs 42 have been lifted from the body by the movement of the switch button 17 up the sloping rails 34 on the button cover. 20. The space I between the fixed contact strip 18 and the movable contact strip 19 at this central position is slightly less than the clearance between the forward lugs 42 and the body 11. Thus, the contacts may be momentarily closed by pushing down on the switch button 17 against the spring-like action of the movable contact strip 19.

As the switch button 17 is moved further forwardly to an on position, the rearward ridge of the camming surface 22 slides up over the forward hump on the movable contact strip 19, which is thereby forced into positive contact with the fixed contact strip 18. The switch button 17 is held in this on position by the action of the rearward ridge 40 on the forward hump 45.

It is a further refinement of the preferred embodiment that the

screws

27 and 29, used to hold the assembled switch together on the flashlight body 11, are coated on their threaded portions with an insulating material (not shown). By this means, the heads of the screws are effectively insulated from the electrical circuit of the flashlight, and there is no possibility of switching on the flashlight merely by inadvertent electrical connection between the heads of the screws.

From the foregoing, it will be seen that the flashlight switch in the fonn shown herein for purposes of illustration combines .the desirable features of rugged, weather-resistant construction, reliable and positive operation, and ease of assembly and replacement of parts. It will also be seen that, while one particular form of the invention has been illustrated and described, various modifications can be made without departing from the spirit and scope of the invention.

l claim:

1. In a flashlight having an insulated body, the combination comprising:

first and second terminals integral with the body;

a fixed contact strip secured to said first tenninal and extending toward said second terminal exteriorly along the body;

a resilient movable contact strip secured to said second terminal and extending toward said first terminal in partly overlapping relationship with said fixed contact strip, said movable contact strip being generally arcuate in shape with at least one convex hump of relatively small radius intermediate its ends;

a hollow switch cover having side walls and a top wall, said switch cover being removably secured to the flashlight body to surround said fixed and movable contact strips, and said top wall having an elongated opening therethrough; and

a switch button sized to fit under said switch cover to overlie said movable contact strip and protrude partly through said elongated opening, said switch button having at least two transverse ribs thereunder, and being movable between an off" position, in which both of said ribs are positioned on the side of said convex hump closer to said second terminal, and an on" position, in which both of said ribs are positioned on the opposite side of said convex hump and said movable contact strip is thereby cammed into electrical contact with said fixed contact strip, said switch button also being movable to an intermediate position, between said of and on positions, in which said ribs straddle said convex hump and in which said resilient movable contact strip is movable into momentary contact with said fixed contact strip by momentary depression of said switch button, whereby said ribs and said convex hump coact as a detent to provide positive retention of said switch button in any of said off", on and intermediate positions.

2. The combination defined in claim 1, further including at least two screws extending through holes in said switch cover and through corresponding holes in said contact strips to engage corresponding threaded holes in said terminals and thereby to secure said switch cover and said contact strips to the flashlight body and to hold said contact strips in electrical contact with said terminals.

3. The combination defined in claim 1, wherein:

said switch button has three transverse ribs thereunder; and

said movable contact strip has a plurality convex humps intermediate its ends, with concave depressions between adjacent ones of said humps spaced along said movable contact strip to coact with said ridges and thereby positively retain said switch button at any of said off, on and intermediate positions.

4. The combination defined in claim 1, wherein:

said switch button and said switch cover are provided with inter-engaging complementary guide-rail and groove means for guiding said switch button between said on and off positions, said guide-rail means being inclined with respect to the flashlight body thereby to position said switch button closer to the body in said off position than in said onposition; and

said switch button is further provided with at least one lug depending therefrom to abut the flashlight body in said of position but not in said on or intermediate positions, thereby to prevent depression of said switch button and consequent contact between said contact strips in said off position.

Claims

1. In a flashlight having an insulated body, the combination comprising: first and second terminals integral with the body; a fixed contact strip secured to said first terminal and extending toward said second terminal exteriorly along the body; a resilient movable contact strip secured to said second terminal and extending toward said first terminal in partly overlapping relationship with said fixed contact strip, said movable contact strip being generally arcuate in shape with at least one convex hump of relatively small radius intermediate its ends; a hollow switch cover having side walls and a top wall, said switch cover being removably secured to the flashlight body to surround said fixed and movable contact strips, and said top wall having an elongated opening therethrough; and a switch button sized to fit under said switch cover to overlie said movable contact strip and protrude partly through said elongated opening, said switch button having at least two transverse ribs thereunder, and being movable between an ''''off'''' position, in which both of said ribs are positioned on the side of said convex hump closer to said second terminal, and an ''''on'''' position, in which both of said ribs are positioned on the opposite side of said convex hump and said movable contact strip is thereby cammed into electrical contact with said fixed contact strip, said switch button also being movable to an intermediate position, between said ''''off'''' and ''''on'''' positions, in which said ribs straddle said convex hump and in which said resilient movable contact strip is movable into momentary contact with said fixed contact strip by momentary depression of said switch button, whereby said ribs and said convex hump coact as a detent to provide positive retention of said switch button in any of said ''''off''''on'''' and intermediate positions.

3. The combination defined in claim 1, wherein: said switch button has three transverse ribs thereunder; and said movable contact strip has a plurality convex humps intermediate its ends, with concave depressions between adjacent ones of said humps spaced along said movable contact strip to coact with said ridges and thereby positiVely retain said switch button at any of said ''''off,'''' ''''on'''' and intermediate positions.

4. The combination defined in claim 1, wherein: said switch button and said switch cover are provided with inter-engaging complementary guide-rail and groove means for guiding said switch button between said ''''on'''' and ''''off'''' positions, said guide-rail means being inclined with respect to the flashlight body thereby to position said switch button closer to the body in said ''''off'''' position than in said ''''on'''' position; and said switch button is further provided with at least one lug depending therefrom to abut the flashlight body in said ''''off'''' position but not in said ''''on'''' or intermediate positions, thereby to prevent depression of said switch button and consequent contact between said contact strips in said ''''off'''' position.