GB2296822A - Switch for a flashlight - Google Patents

Abstract

A switch for a flashlight includes an insulated hollow seat member 4 having four conductive contacts, eg 462, mounted thereon, two of which are connected to a lamp and the other two of which are connected to a pulse generating circuit 7. An insulated cylindrical member 6 is disposed rotatably in the seat member 4 and has conductive members, 63 and 64, mounted thereon, one of which 64 is connected to a power source. The cylindrical member 6 is manually operable to rotate between a switch-off position, a first switch-on position, wherein the, one conductive member 64 contacts one of the contacts of the seat member 4 which is connected to the lamp so as to cause the lamp to generate a constant light output, and a second switch-on position, wherein the one conductive member 64 contacts one of the contacts of the seat member 4 connected to the pulse generating circuit 7 and the other conductive member connects the other contact of the seat member 4 which is connected to the pulse generating circuit 7 to a contact connected to the lamp so as to cause the lamp unit 22 to generate a blinking light output. <IMAGE>

Description

SWITCHING APPARATUS FOR A FLASHLIGHT This invention relates to a switching apparatus for a flashlight, more particularly to a switching apparatus which is operable to control a lamp of the flashlight to generate selectively a constant light output or a blinking light output.

Referring to Fig. 1, a conventional switching apparatus 12 is disposed in a barrel 10 of a flashlight and is operable to connect electrically a lamp 14 to a power source 111, such as a battery. The conventional switching apparatus 12 usually includes a button assembly 16. The button assembly 16 includes a hollow seat member 160 disposed securely in the barrel 10, a first conductive wire 161 having a first end portion connected electrically to the power source 111 and a second end portion, a second conductive wire 162 having a first end portion connected electrically to the lamp 14 and a second end portion, and a push rod 163 which extends slidably in the seat member 160 and which is operable between a switch-on position, wherein the second end portion of the first conductive wire 161 is connected electrically to the second end portion of the second conductive wire 162 to connect the lamp 14 to the power source 111 so as to control the lamp 14 to generate a constant light output, and a switch-off position, wherein the second end portion of the first conductive wire 161 is disconnected from the second end portion of the second conductive wire 162 to disconnect the lamp 14 from the power source 111 so as to turn off the lamp 14. The aforementioned conventional switching apparatus 12 is only capable of controlling the lamp 14 to generate the constant light output.

A second type of a conventional switching apparatus (not shown) is available in the market and is capable of controlling the lamp (not shown) to generate selectively one of the constant light output and a blinking light output. However, the second type of the conventional switching apparatus includes a first button assembly (not shown) which is operable to control the lamp to generate the constant light output and a second button assembly (not shown) which is operable to control the lamp to generate the blinking light output. The first and second button assemblies increase the size of the flashlight and are inconvenient to operate alternately.

Therefore, the main objective of the present invention is to provide a switching apparatus which is operable to control a lamp of a flashlight to generate selectively one of a constant light output and a blinking light output.

According to the present invention, a switching apparatus is to be installed in a flashlight and includes an insulated hollow seat member having first, second, third and fourth conductive contacts mounted thereon. The first and fourth conductive contacts are connected electrically to a lamp unit of the flashlight. A pulse generating circuit has an input terminal connected electrically to the second conductive contact and an output terminal connected electrically to the third conductive contact. An insulated cylindrical member is disposed rotatably in the seat member and has first and second conductive members mounted thereon. The first conductive member is connected electrically to a power source of the flashlight.The cylindrical member is manually operable to rotate relative to the seat member among aS switch-off position, wherein the conductive members of the cylindrical member are not in contact with the conductive contacts of the seat member so as to turn off the lamp unit, a first switch-on position, wherein the first conductive member of the cylindrical member connects the first conductive contact of the seat member to the power source and the second conductive member of the cylindrical member is not in contact with the conductive contacts of. the seat member so as to control the lamp unit to generate the constant light output, and a second switch-on position, wherein the first conductive member of the cylindrical member connects the second conductive contact of the seat member to the power source to connect the pulse generating circuit to the power source and the second conductive member of the cylindrical member connects the third conductive contact of the seat member to the fourth conductive contact of the seat member to connect the lamp unit to the pulse generating circuit so as to control the lamp unit to generate the blinking light output.

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment, with reference to the accompanying drawings, of which: Fig. 1 is a fragmentary sectional view illustrating a conventional switching apparatus which is incorporated in a flashlight; Fig. 2 is an exploded view of a preferred embodiment of a switching apparatus according to the present invention; Fig. 3 is a fragmentary enlarged view in which an annular inner wall of a cylindrical head of a seat member of the preferred embodiment is translated onto a plane; Fig. 4 is a fragmentary sectional view illustrating how the preferred embodiment is mounted within a barrel of a flashlight;; Fig. 5 is a plan view illustrating the relationship among an insulated cylindrical member and two first curved plates of a first conductive member of the preferred embodiment; Fig. 6 is a sectional view of a semi-assembled switching apparatus according to the present invention; Fig. 7 is a schematic circuit diagram of a pulse generating circuit of the preferred embodiment; Figs. 8A and 8B are sectional views showing the semi-assembled switching apparatus according to the present invention when the cylindrical member is in one of the switch-off, first switch-on, second switch-on and third switch-on positions; Figs. 9A and 9B are views similar to that of Figs.

8A and 8B, the cylindrical member being rotated from one of the switch-off, first switch-on, second switch-, on and third switch-on positions to another one of the switch-off, first switch-on, second switch-on and third switch-on positions; Figs. l0A and lOB are views similar to that of Figs.

9A and 9B, the cylindrical member being in still another one of the switch-off, first switch-on, second switch-on and third switch-on positions; Fig. 11 is a view in which the annular inner wall of the cylindrical head of.the seat member of the preferred embodiment is translated onto a plane to illustrate operation of the same; and Fig. 12 is a fragmentary enlarged view of a cylindrical base of the seat member of the preferred embodiment.

Referring to Fig. 2, a switching apparatus according to the present invention is to be installed in a flashlight (see Fig. 4) and includes an insulated hollow mounting cylinder 3, an insulated hollow seat member 4, a button assembly 5, an insulated cylindrical member 6 and a pulse generating circuit 7.

The mounting cylinder 3 includes a first cylinder half 31 and a second cylinder half 34 which complements and which is connected to the first cylinder half 31.

The first cylindrical half 31 is formed with a radial button retaining passage 311 which is confined by a tubular member 32 (see Fig. 4) extending radially and inwardly into the mounting cylinder 3. The mounting cylinder 3 further has an open end 312 which is adapted to be connected to a lamp seat 23 (see Fig. 4) of the flashlight.

Referring now to Figs. 2 and 3, the seat member 4 is disposed immovably in the mounting cylinder 3 and has a hollow cylindrical base 42 and a hollow cylindrical head 41 which extends upwardly from the cylindrical base 42 and through the radial button retaining passage 311 and which is communicated with the cylindrical base 42. The cylindrical head 41 has an threaded annular outer wall 411 to which an internally-threaded locking ring 422 is connected so as to prevent axial movement of the seat member 4 relative to the mounting cylinder 3. A cover plate 423 is mounted on the mounting cylinder 3 and covers the radial button retaining passage 311 so as to prevent seepage of water into the retaining passage 311. The cover plate 423 has a flexible dome-shaped portion 424.The cylindrical head 4 further has an annular inner wall which is formed with a plurality of angularly spaced and vertically extending ribs 43. Each adjacent two of the angularly spaced and vertically extending ribs 43 cooperatively define a slide groove 44 therebetween. Each rib 43 has an inclined lowermost end surface 431 which slopes from one adjacent slide groove 44 to another adjacent slide groove 44.

Referring now to Figs. 2, 4 and 12, the cylindrical base 42 is sized so as to prevent extension thereof into the retaining passage 311 of the mounting cylinder 3 and has an upper end portion formed with two diametrically opposed notches 425 which engage a lower end portion of the tubular member 32 of the first cylinder half 31 so as to prevent rotation of the cylindrical base 42 relative to the mounting cylinder 3. The cylindrical base 42. is formed with a plurality of radially extending through-holes 421. In the present embodiment, the cylindrical base 42 is formed with nine through-holes 421 which are arranged in first, second and third rows, 451, 452 and 453, of three through-holes 421 each. Each through-hole 421 of each row 451,452,453 is axially spaced from and axially aligned with an adjacent one.A first conductive contact 461 extends into a first one of the throughholes 421, which is the lowermost one of the first row 451, and is adapted to be connected electrically to a lamp unit 22 (see Fig. 4). A second conductive contact 462 extends into a second one of the through-holes 421 which is the lowermost one of the second row 452 and which is angularly spaced from and circumferentially aligned with the first one of the through-holes 421. A third conductive contact 463 extends into a third one of the through-holes 421 which is immediately above the second one of the through-holes 421. A fourth conductive contact 464 extends into a fourth one of the through-holes 421 which is immediately above the third one of the through-holes 421, and is adapted to be connected electrically to the lamp unit 22.A fifth conductive contact 465 extends into a fifth one of the through-holes 421 which is the lowermost one of the third row 453 and which is angularly spaced from and circumferentially aligned with the second one of the through-holes 421. A sixth conductive contact 466 extends into a sixth one of the through-holes 421 which is immediately above the fifth one of the through-holes 421 and which is angularly spaced from and circumferentially aligned with the third one of the through-holes 421. A seventh conductive contact 467 extends into a seventh one of the through-holes 421 which is above the sixth one of the through-holes 421 and which is angularly spaced from and circumferentially aligned with the fourth one of the through-holes 421. The seventh conductive contact 467 is adapted to be connected electrically to the lamp unit 22.

It should be noted that since the numbers of through-holes 421 in each row 451,452,453 is equal, the positions of the conductive contacts, 461 to 467, can be interchanged. That is, the first conductive contact 461 can extend into the through-hole 421 of the second row 452, while the conductive contacts 462,463,464 can extend into the through-holes 421 of the first row 451.

As best shown in Fig. 6, the cylindrical base 42 further has a bottom 48 provided with a first conductive plate 49. A second conductive plate 47 has a first end portion which is adapted to be connected electrically to a power source 211 (see Fig. 4) of the flashlight and a second end portion which extends into the cylindrical base 42 and which is in contact with the first conductive plate 49.

Referring now to Figs. 4 and 7, the pulse generating circuit 7 is installed in the mounting cylinder 3. In the present embodiment, the pulse generating circuit 7 is a charging and discharging circuit. The pulse generating circuit 7 has a first input terminal 71 which is connected electrically to the second conductive contact 462, a second input terminal 72 which is connected electrically to the fifth conductive terminal 465, and an output terminal 73 which is connected electrically to the third and sixth conductive contacts, 463 and 466.It should be noted that since a first resistor (R1) is connected electrically to the first input terminal 71, and since a second resistor (R2) is connected electrically to the second input terminal 72 and has a resistance value different from that of the first resistor (R1), the pulse generating circuit 7 will generate a first pulse train signal when a voltage is applied across the first input terminal 71 and the output terminal 73 and will generate a second pulse train signal, which has a frequency different from that of the first pulse train signal, when the voltage is applied across the second input terminal 72 and the output terminal 73.

Referring now to Figs. 2, 5 and 6, the cylindrical member 6 is disposed rotatably in the cylindrical base 42 of the seat member 4 and rests on the first conductive plate 49. The cylindrical member 6 has an upper end surface formed with two diametrically spaced engaging holes 62 and is further formed with a throughhole 61 between the engaging holes 62. A first conductive member 64 includes two diametrically opposed and electrically connected first curved plates 641 which are mounted on an outer peripheral wall of the cylindrical member 6. Each of the first curved plates 641 of the first conductive member 64 has an end portion 642 which extends into and which is around the through-hole 61 of the cylindrical member 6, and a second end portion 643 which is formed with a boss 644.

As best shown in Figs. 2 and 8B, a second conductive member 63 includes two diametrically opposed second curved plates 631 which are mounted on the outer peripheral wall of the cylindrical member 6 above the first curved plates 641 of the first conductive member 64. Each of the second curved plates 631 has a forked end portion 632 which is provided with two prongs 634., Each of the prongs 634 is formed with a boss 633.

The cylindrical member 6 is manually operable to rotate relative to the seat member 4 among a switch-off position, wherein the bosses 644,633 of the conductive members 64,63 of the cylindrical member 6 are not in contact with the conductive contacts, 461 to 467, of the seat member so as to turn off the lamp unit 22, a first switch-on position, wherein one of the bosses 644 of the first conductive member 64 of the cylindrical member 6 connects the first conductive contact 461 of the seat member 4 to the power source 211 and the bosses 633 of the second conductive member 63 of the cylindrical member 6 are not in contact with the conductive contacts, 461 to 467, of the seat member 4 so as to control the lamp unit 22 to generate a constant light output, a second switch-on position, wherein one of the bosses 644 of the first conductive member 64 of the cylindrical member 6 connects the second conductive contact 462 of the seat member 4 to the power source 211 to connect the first input terminal 71 of the pulse generating circuit 7 to the power source 211 and the bosses 633 of the second conductive member 63 of the cylindrical member 6 connect the third conductive contact 463 of the seat member 4 to the fourth conductive contact 464 of the seat member 4 to connect the lamp unit 22 to the output terminal 73 of the pulse generating circuit 7 so as to, control the lamp unit 22 to generate a first blinking light output, and a third switch-on position, wherein one of the bosses 644 of the first conductive member 64 of the cylindrical member 6 connects the fifth conductive contact 465 of the seat member 4 to the power source 211 to connect the second input terminal 72 of the pulse generating circuit 7 to the power source 211 and the bosses 633 of the second conductive member 63 of the cylindrical member 6 connect the sixth conductive contact 466 of the seat member 4 to the seventh conductive contact 467 of the seat member 4 to connect the lamp unit 22 to the output terminal 73 of the pulse generating circuit 7 so as to control the lamp unit 22 to generate a second blinking light output.

Referring now to Figs. 2 and 6, the button assembly 5 includes a rotatable rod 52 which is disposed movably and rotatably in the cylindrical head 41 of the seat member 4 and which has a lower end portion that is formed with an outwardly extending radial flange 523.

The radial flange 523 has an upper end surface formed with a plurality of angularly arranged teeth 521 and a lower end surface opposite to the upper end surface.

Each of the teeth 521 of the rotatable rod 52 has an inclined abutting surface. The rotatable rod 52 further has two diametrically spaced insert rods 524 which extend downwardly and respectively from the lower, end surface of the radial flange 523 and into a respective one of the engaging holes 62 in the upper end surface of the cylindrical member 6. The rotatable rod 52 further has a plurality of angularly spaced protrusions 522 which project outwardly and radially from the flange 523 and which extend movably and respectively in a respective one of the slide grooves 44. In the present embodiment, the rotatable rod 52 is formed with four protrusions 522. Each of the protrusions 522 has an inclined uppermost end surface 5221 which complements the inclined lowermost end surface 431 of the ribs 43.

A tubular push rod 51 is disposed movably in the cylindrical head 41 and is sleeved on the rotatable rod 52. The push rod 51 has an upper press surface 510 and a lower end portion which is formed with a plurality of angularly arranged teeth 511 and a plurality of angularly spaced projections 512. In the present embodiment, the push rod 51 is formed with four projections 512. The projections 512 project outwardly and radially from the lower end portion and extend movably and respectively into a respective one of said slide grooves 44.Each of the teeth 511 of the push rod has an inclined abutting surface which complements the inclined abutting surfaces of the teeth 521 of the rotatable rod 52 and which abuts partly the inclined abutting surface of a respective one of the teeth 521, of the rotatable rod 52 when the protrusions 522 of the rotatable rod 52 extend into the respective one of the slide grooves 44. Each of the projections 512 has an inclined lowermost end 5121 which complements the uppermost end surfaces 5221 of the protrusions 522 of the rotatable rod 52. The button assembly 5 further includes a first hollow cylinder 54 on which the rotatable rod 52 is sleeved.A second hollow cylinder 55 is retained in the central through-hole 61 of the cylindrical member 6 and is in contact with the first conductive plate 49, the end portions 642 of the first curved plates 641 of the first conductive member 64 and the second end portion of the second conductive member 47. In the present embodiment, the first and second hollow cylinders, 54 and 55, are conductors.

A coil spring 53 has a first end portion which extends into the first hollow cylinder 54 and a second end portion which extends into the second hollow cylinder 55 so as to bias the rotatable rod 52 toward the push rod 51.

Referring now to Fig. 4, the switching apparatus according to the present invention is adapted to be installed in a flashlight which includes a hollow barrel 2 (partly shown). The barrel 2 has the lamp unit 22 and the power source 211 installed therein.

The mounting cylinder 3 is received fittingly in the barrel 2. The lamp unit 22 is mounted on the lamp seat1 23 which is connected to the open end 312 of the mounting cylinder 3. The flexible dome-shaped portion 424 of the cover plate 423 is exposed from the barrel 2. The upper press surface 510 of the push rod 5 is located adjacent to the dome-shaped portion 424 of the cover plate 423.

Referring now to Figs. BA, 8B, 11 and 12, supposing the cylindrical member 6 is initially in the third switch-on position, the protrusions 522 of the rotatable rod 52 extend into a respective one of the slide grooves 44, and the lamp unit 22 is controlled to generate the second blinking output.At this time, application of pressure on the dome-shaped portion 424 of the cover plate 423 will cause the push rod 51 to move axially downward relative to the seat member 4 to cause corresponding movement of the rotatable rod 52 and compression of the coil spring 53 so as to move the protrusions 522 of the rotatable rod 52 away from the respective one of the slide grooves 44 and to cause the teeth 521 of the rotatable rod 52 to engage completely the teeth 511 of the push rod 51, thereby rotating the rotatable rod 52 to misalign the protrusions 522 of the rotatable rod 52 with the respective one of the slide grooves 44 and to cause the uppermost end surfaces 5221 of the protrusions 522 of the rotatable rod 52 to abut respectively against the lowermost end surface 431 of an adjacent one of the ribs 43. At this stage, as best1 shown in Figs. 9A and 9B, the bosses 633 of the second curved plates 631 of the first conductive member 63 are located respectively between the third and sixth conductive contacts, 463 and 466, and between the fourth and seventh conductive contacts, 464 and 467.

Referring now to Figs. 10A, 10B, 11 and 12, when pressure on the upper press surface 510 of the push rod 51 is released, the coil spring 53 expands to bias the rotatable rod 52 to move. toward the push rod 51, thereby causing the protrusions 522 of the rotatable rod 52 to move past the lowermost end surface 431 of the adjacent one of the ribs 43 so as to extend respectively into an adjacent one of the slide grooves 44 in order to rotate the cylindrical member 6 relative to the seat member 4 from the third switch-on position into the second switch-on position.

It should be noted that further operation of the push rod 51 will cause the cylindrical member 6 to rotate relative to the seat member 4 from the second switch-on position to the first switch-on position.

Similarly, yet further operation of the push rod 51 after the cylindrical member 6 rotates to the first switch-on position will cause the cylindrical member 6 to rotate relative to the seat member 4 from the first switch-on position to the switch-off position.

It should be appreciated that the number of through-1 holes 421 of each row 451,452,453 in the cylindrical base 42 of the seat member 4 is not limited to three, and the number of rows is also not limited to three.

The cylindrical base 42 may be constructed to have more or less than three rows of more or less than three through-holes each. Similarly, the number of prongs 634 of the second curved plates 631 of the second conductive member 63 depends on the numbers of throughholes in each row.

Claims (10)

CLAIMS:

1. A switching apparatus for a flashlight, said flashlight including a power source and a lamp unit which is to be connected electrically to said power source via said switching apparatus and which is controlled by said switching apparatus so as to generate one of a constant light output and a blinking light output, said switching apparatus comprising: an insulated hollow seat member having first, second, third and fourth conductive contacts mounted thereon, said first and fourth conductive contacts being adapted to be connected electrically to said lamp unit; a pulse generating circuit having an input terminal connected electrically to said second conductive contact and an output terminal connected electrically to said third conductive contact; and an insulated cylindrical member disposed rotatably in said seat member, said cylindrical member having first and second conductive members mounted thereon, said first conductive member being adapted to be connected electrically to said power source, said cylindrical member being manually operable to rotate relative to said seat member among a switch-off position, wherein said conductive members of said cylindrical member are not in contact with said conductive contacts of said seat member so as to turn off said lamp unit, a first switch-on position, wherein said first conductive member of said cylindrical member connects said first conductive contact of said seat member to said power source and said second conductive member of said cylindrical member is not in contact with said conductive contacts of said seat member so as to control said lamp unit to generate said constant light output, and a second switch-on position, wherein said first conductive member of said cylindrical member connects said second conductive contact of said seat member to said power source to connect said pulse generating circuit to said power source and said second conductive member of said cylindrical member connects said third conductive contact of said seat member to said fourth conductive contact of said seat member to connect said lamp unit to said pulse generating circuit so as to control said lamp unit to generate said blinking light output.

2. A switching apparatus as claimed in Claim 1, wherein said seat member has a hollow cylindrical base which is formed with a plurality of radially extending throughholes and which has said cylindrical member received therein, said first conductive contact extending into a first one of said through-holes, said second conductive contact extending into a second one of said throughholes which is angularly spaced from and which is circumferentially aligned with said first one of said through-holes, said third conductive contact extending into a third one of said through-holes which is axially spaced from and which is axially aligned with said second one of said through-holes, said fourth conductive contact extending into a fourth one of said through-holes which is axially spaced from and which is axially aligned with said third one of said throughholes.

3. A switching apparatus as claimed in Claim 2, wherein: said seat member further has a hollow cylindrical head which extends upwardly from and which is, communicated with said cylindrical base thereof, said cylindrical head of said seat member having an annular inner wall formed with a plurality of angularly spaced and vertically extending ribs, each adjacent two of said angularly spaced and vertically extending ribs cooperatively defining a slide groove therebetween, each of said ribs having an inclined lowermost end surface sloping from one adjacent said slide groove to another adjacent said slideXgroove; said cylindrical member has an upper end surface formed with two diametrically spaced engaging holes; said switching apparatus further includes a button assembly with:: a rotatable rod which is disposed movably and rotatably in said cylindrical head of said seat member and which has a lower end portion that is formed with an outwardly extending radial flange, said radial flange having an upper end surface formed with a plurality of angularly arranged teeth and a lower end surface opposite to said upper end surface, each of said teeth of said rotatable rod having an inclined abutting surface, said rotatable rod further having two diametrically spaced insert rods which extend downwardly and respectively from said lower end surface of said radial flange and into a respective one of said engaging holes in said upper end surface of said cylindrical member, said rotatable rod further having a, plurality of angularly spaced protrusions which project outwardly and radially from said flange and which extend movably and respectively in a respective one of said slide grooves, each of said protrusions of said rotatable rod having an inclined uppermost end surface which complements said inclined lowermost end surface of said ribs;; a tubular push rod which is disposed movably in said cylindrical head and- which is sleeved on said rotatable rod, said push rod having an upper press surface and a lower end portion formed with a plurality of angularly arranged teeth and a plurality of angularly spaced projections, said projections projecting outwardly and radially from said lower end portion and extending movably and respectively into a respective one of said slide grooves, each of said teeth of said push rod having an inclined abutting surface which complements said inclined abutting surfaces of said teeth of said rotatable rod and which abuts partly said inclined abutting surface of a respective one of said teeth of said rotatable rod when said protrusions of said rotatable rod extend into said respective one of said slide grooves; and a coil spring biasing said rotatable rod toward said push rod; whereby, when said upper press surface of said push rod is depressed, said push rod moves axially downward, relative to said seat member to cause corresponding movement of said rotatable rod and to cause compression of said coil spring so as to move said protrusions of said rotatable rod away from said respective one of said slide grooves and to cause said teeth of said rotatable rod to engage completely said teeth of said push rod, thereby rotating said rotatable rod to misalign said protrusions of said rotatable rod with said respective one of said slide grooves and to cause said uppermost end surfaces of said protrusions of said rotatable rod to abut respectively against said lowermost end surface of an adjacent one of said ribs, and whereby, when said upper press surface of said push rod is released, said coil spring expands to bias said rotatable rod to move toward said push rod, thereby causing said protrusions of said rotatable rod to move past said lowermost end surface of said adjacent one of said ribs so as to extend respectively into an adjacent one of said slide grooves in order to rotate said cylindrical member relative to said seat member from one of said switch-off, first switch-on and second switch-on positions into another one of said switch-off, first switch-on and second switch-on positions.

4. A switching apparatus as claimed in Claim 3, wherein said cylindrical member has an outer peripheral wall, said first conductive member including two, diametrically opposed and electrically connected first curved plates mounted on said outer peripheral wall of said cylindrical member, each of said first curved plates being formed with a boss for contacting a corresponding one of said first and second conductive contacts when said cylindrical member is in one of said first and second switch-on positions.

5. A switching apparatus as claimed in Claim 4, wherein said second conductive member includes two diametrically opposed second curved plates mounted on said outer peripheral wall of said cylindrical member above said first curved plates of said first conductive member, each of said second curved plates having a forked end portion provided with two prongs, each of said prongs being formed with a boss for contacting a corresponding one of said third and fourth conductive contacts when said cylindrical member is in said second switch-on position.

6. A switching apparatus as claimed in Claim 5, wherein said rotatable rod is hollow, said cylindrical member being formed with a central through-hole between said engaging holes, said button assembly further including a first hollow cylinder on which said rotatable rod is sleeved and a second hollow cylinder retained in said central through-hole of said cylindrical member, said coil spring of said button assembly having a first end portion extending into said first hollow cylinder and a second end portion extending into said second hollow cylinder.

7. A switching apparatus as claimed in Claim 6, wherein each of said first curved plates of said first conductive member has an end portion which extends into and which is around said through-hole of said cylindrical member, said second hollow cylinder being a conductor and being normally in contact with said end portions of said first curved plates of said first conductive member.

8. A switching apparatus as claimed in Claim 7, wherein said hollow cylindrical base of said seat member has a bottom provided with a first conductive plate on which said cylindrical member is disposed rotatably, said first conductive plate being in contact with said second hollow cylinder and said first curved plates of said first conductive member, said cylindrical member further including a second conductive plate having a first end portion adapted to be connected electrically to said power source and a second end portion which extends into said seat member and which is in contact with said first conductive plate, said second end portion of said second conductive plate being in contact with said boss of a respective one of said first curved plates of said first conductive member when said cylindrical member is in one of said first and second switch-on positions.

9. A switching apparatus as claimed in Claim 3, further comprising an insulated hollow mounting cylinder formed with a radial button retaining passage, said seat member being disposed immovably in said mounting cylinder and having said cylindrical head extending through said radial button retaining passage, said mounting cylinder including a cover plate which is mounted on said mounting cylinder and which covers said radial button retaining passage.

10. A switching apparatus substantially as herein before described with reference to and as illustrated in Figs. 2 to 12 of the accompanying drawings.