Heat insulation arrangement of indicating instrument

• US 6,520,109 B2
• Filed: 03/26/2001
• Issued: 02/18/2003
• Est. Priority Date: 03/30/2000
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Komura, Takashi
• Primary Examiner(s): Gutierrez, Diego
• Assistant Examiner(s): Smith, R. Alexander
• Application Number:
  US09/816,143
• Publication Number:
  US 20010025596A1
• Time in Patent Office: 694 Days
• Field of Search: 116/62.1, 116/284, 116/285, 116/286, 116/287, 116/288, 116/305, 362/29, 362/30, 362/DIG.800, 361/772, 361/773, 361/774
• US Class Current: 116/288
• CPC Class Codes: B60K 2360/698 Pointers of combined instruments
• CPC Class Codes: B60K 2370/698 Pointers of combined instruments
• CPC Class Codes: G01D 3/08 with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown
• CPC Class Codes: H02K 2203/03 Machines characterised by the wiring boards, i.e. printed circuit boards or similar structures for connecting the winding terminations
• CPC Class Codes: H02K 2211/03 Machines characterised by circuit boards, e.g. pcb
• CPC Class Codes: H02K 5/225 Terminal boxes or connection arrangements specially adapted for submersible motors H02K5/132
• CPC Class Codes: H05K 1/18 Printed circuits structurally associated with non-printed electric components H05K1/0201, H05K1/023, H05K1/0243, and H05K1/16 take precedence
• CPC Class Codes: H05K 2201/09972 Partitioned, e.g. portions of a PCB dedicated to different functions; Boundary lines therefore; Portions of a PCB being processed separately or differently
• CPC Class Codes: H05K 2201/1009 Electromotor
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 3/3447 Lead-in-hole components H05K3/3415 takes precedence

Abstract

An indicating instrument includes a transparent dial plate, a printed circuit board disposed behind the dial plate, a drive unit disposed behind the printed circuit board having a plurality of lead wires soldered to the printed circuit board, a light conductive luminous pointer and a light emitting diode disposed on the printed circuit board near a rotary shaft so that the pointer can receive light emitted from the light emitting diode. Each end of the plurality of lead wires is disposed on the printed circuit board at a distance from the light emitting diode sufficient to insulate the light emitting diode from heat of soldering the plurality of lead wires to the circuit board.

Claims

1. An indicating instrument comprising:

a transparent dial plate;

a printed circuit board disposed behind said dial plate;

a drive unit having a drive control section disposed behind said printed circuit board and a rotary shaft extending from said drive control section through said printed circuit board toward the center of said dial plate, said drive control section having a step motor and a plurality of lead wires soldered to said printed circuit board;

a light conductive luminous pointer having a base portion carried by said rotary shaft to rotate along the surface of said dial plate; and

a light emitting diode disposed on said printed circuit board near said rotary shaft so that said base portion of said pointer can receive light emitted from said diode, said light emitting diode being soldered to said printed circuit board;

wherein

said printed circuit board has a first portion soldered to said light emitting diode and a second portion separately soldered to said plurality of lead wires disposed at a distance from said light emitting diode;

said drive control section comprises a case member for accommodating said step motor and a terminal box for accommodating said plurality of lead wires so that said rotary shaft and said plurality of lead wires respectively extend upward from said drive unit at opposite ends of said drive unit, whereby

each end of said plurality of lead wires is disposed on said printed circuit board at the distance from said light emitting diode to insulate said light emitting diode from heat of soldering said plurality of lead wires to said circuit board.

2. The indicating instrument as claimed in claim 1, wherein

said distance is about 10 mm.

3. The indicating instrument as claimed in claim 1, further comprising at least one additional light emitting diode, wherein

each of said light emitting diodes is disposed at the distance from said ends of said lead wires sufficient to insulate said light emitting diodes from heat of soldering said ends to said printed circuit board.

4. The indicating instrument as claimed in claim 1, wherein

each said lead wire extends radially outward so that said end can be soldered to a portion that is located remote from said rotary shaft.

5. The indicating instrument as claimed in claim 1, wherein each of said plurality of lead wires has a beam-like portion disposed in said case member and extended along said printed circuit board and a U-shaped portion disposed in said terminal box.

6. An indicating instrument comprising:

a dial plate having a through hole;

a printed circuit board disposed behind said dial plate;

a drive unit having a drive control section disposed behind said printed circuit board and a rotary shaft extending from said drive control section through said printed circuit board toward said through hole of said dial plate, said drive control section having a step motor and a plurality of lead wires soldered to said printed circuit board;

a light conductive luminous pointer having a base portion carried by an end of said rotary shaft via said through hole to rotate along the surface of said dial plate; and

a light emitting diode disposed on said printed circuit board near said rotary shaft so that said base portion of said pointer can receive light emitted from said light emitting diode through said through hole, said light emitting diode being soldered to said printed circuit board;

wherein

said printed circuit board has a first portion soldered to said light emitting diode and a second portion separately soldered to said plurality of lead wires disposed at a distance from said light emitting diode;

said drive control section comprises a case member for accommodating said step motor and a terminal box for accommodating said plurality of lead wires so that said rotary shaft and said plurality of lead wires respectively extent upward from said drive unit at opposite ends of said drive unit, whereby

each of said plurality of lead wires has an end soldered to portions of said printed circuit board at the distance from said light emitting diode sufficient to insulate said light emitting diode from heat of soldering said ends to said printed circuit board.

7. The indicating instrument as claimed in claim 6, wherein

said distance is about 10 mm.

8. The indicating instrument as claimed in claim 6, further comprising at least one additional light emitting diode, wherein

said dial plate comprises a transparent member;

and

each end of said plurality of lead wires is soldered to a portion of said printed circuit board at the distance sufficient to insulate said light emitting diodes from heat of soldering said ends to said printed circuit board.

9. An indicating instrument comprising:

a dial plate having a through hole;

a printed circuit board disposed behind said dial plate, said printed circuit board having a plurality of connectors soldered to said printed circuit board;

a drive unit having a drive control section disposed behind said printed circuit board and a rotary shaft extending from said drive control section through said circuit board toward said through hole of said dial plate, said drive control section having a step motor with a plurality of lead wires connected to said plurality of connectors and a resinous gear train connected between said step motor and said rotary shaft;

a light conductive luminous pointer having a base portion carried by an end of said rotary shaft to rotate along the surface of said dial plate; and

a light emitting diode disposed on said printed circuit board near said rotary shaft so that said base portion of said pointer can receive light emitted from said light emitting diode through said through hole, said light emitting diode being soldered to said printed circuit board, wherein

said printed circuit board has a first portion soldered to said light emitting diode and a second portion separately soldered to said plurality of lead wires disposed at a distance from said light emitting diode;

said drive control section comprises a case member for accommodating said step motor and a terminal box for accommodating said plurality of lead wires so that said rotary shaft and said plurality of lead wires respectively extend upward from said drive unit at opposite ends of said drive unit, whereby each end of said plurality of lead wire is disposed on said printed circuit board at the distance from said light emitting diode to insulate said diode from heat of soldering said plurality of lead wires to said circuit board.

10. The indicating instrument as claimed in claim 9, further comprising at least one additional light emitting diode.

11. The indicating instrument as claimed in claim 10, wherein

each of said light emitting diodes is a surface-mounting type diode, and

said printed circuit board comprises a first portion to which each of said light emitting diodes is soldered and a second portion to which said plurality of lead wires is soldered after said light emitting diodes is soldered.