Penlight having low magnetic susceptibility

• US 6,056,415 A
• Filed: 04/08/1998
• Issued: 05/02/2000
• Est. Priority Date: 04/11/1997
• Status: Expired due to Fees

• Current Assignee: Minrad Incorporated (Piramal Enterprises Limited)
• Original Assignee: Minrad Incorporated (Piramal Enterprises Limited)
• Inventors: Wutz, Philip, Allred, Jimmie B. III, Pyszczek, Michael F., Mott, Richard W., Holdren, Earl R. III, Mozeko, Charles L., Mallon, Jeffrey B., Belstadt, Jack A.
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Sawhney, Hargobind S.
• Application Number:
  US09/057,051
• Time in Patent Office: 755 Days
• Field of Search: 362/202, 362/204, 362/205, 362/118
• US Class Current: 362/202
• CPC Class Codes: F21L 2/00 Systems of electric lighting devices systems employing both electric and non-electric light sources or exchangeable light sources F21L27/00
• CPC Class Codes: F21L 4/005 the device being a pocket lamp F21L4/022, F21L4/045, F21L4/085 take precedence
• CPC Class Codes: F21V 15/01 Housings, e.g. material or assembling of housing parts F21V15/02 takes precedence housings forming signs or letters G09F13/04
• CPC Class Codes: F21V 21/0885 for portable lighting devices

Abstract

A penlight constructed of materials including metal components having very low magnetic susceptibilities is described. The battery powering the penlight lamp is a lithium battery also constructed of materials having low magnetic susceptibilities. The penlight is particularly useful in the vicinity of the strong magnetic field of an MRI scanner.

Claims

1. A flashlight, which comprises:

a) a housing;

b) a lamp;

c) a battery housed inside the housing to electrically energize the lamp, wherein the battery has a first terminal and a second, opposite polarity terminal;

d) a first electrically conductive path connecting between the first terminal and the lamp; and

e) a second electrically conductive path connecting between the second terminal and the lamp, wherein when at least one of the first and second electrically conductive paths is open, the lamp is in an unenergized state and wherein when the at least one open conductive path is closed, the first and second electrically conductive paths are completed to thereby energize the lamp, and wherein at least one of the first and second electrically conductive paths comprise at least a first spring intermediate either a first and a second electrically conductive rods or a first and a second electrically conductive sleeves extending between the lamp and one of the first and second terminals of the battery.

2. The flashlight of claim 1 wherein at least a portion of the first and the second electrically conductive path is of brass.

3. The flashlight of claim 2 wherein the brass is composed of, by weight, about 62 to 65% copper, <

0.02% cadmium, <

0.03% iron, <

0.03% lead, <

0.03% tine, remainder zinc.

4. The flashlight of claim 1 wherein at least one of the first and second terminals of the battery are centered along a longitudinal axis of the battery.

5. The flashlight of claim 1 wherein the battery is an alkali metal battery.

6. The flashlight of claim 1 wherein the first electrically conductive path comprises the first spring intermediate the first and second rods.

7. The flashlight of claim 1 wherein the second electrically conductive path comprises a second spring intermediate the first and second sleeves.

8. The flashlight of claim 1 wherein the first electrically conductive path comprises the first spring intermediate the first and second rods, and the second electrically conductive path comprises a second spring intermediate the first and second sleeves.

9. The flashlight of claim 8 wherein the first and the second springs are coil springs.

10. The flashlight of claim 8 wherein a non-conductive member is disposed between the first electrically conductive path comprising the first spring and the first and the second rods, and the second electrically conductive path comprising the second spring and the first and the second sleeves.

11. The flashlight of claim 10 wherein the first and second springs are substantially radially aligned with each other.

12. The flashlight of claim 1 wherein the first and the second battery terminals are disposed along a longitudinal axis of the battery and the housing.

13. The flashlight of claim 12 wherein the first electrically conductive path connects between the lamp and a positive battery terminal, and the second electrically conductive path connects between the lamp and the negative battery terminal.

14. The flashlight of claim 1 wherein the battery is a lithium/thionyl chloride-bromine chloride battery.

15. A flashlight, which comprises:

a) a housing;

b) a lamp;

c) a battery housed inside the housing to electrically energize the lamp, wherein the battery has a first terminal and a second, opposite polarity terminal;

d) a first electrically conductive path connecting between the first terminal and the lamp; and

e) a second electrically conductive path connecting between the second terminal and the lamp, wherein when at least one of the first and second electrically conductive paths is open, the lamp is in an unenergized state and wherein when the at least one open conductive path is closed, the first and second electrically conductive paths are completed to thereby energize the lamp, and wherein at least one of the first and second electrically conductive paths comprise at least a first spring intermediate either a first and second electrically conductive rods or a first and second electrically conductive sleeves extending between the lamp and one of the first and second terminals of the battery, wherein the battery is an alkali metal battery sealed inside of an austenitic stainless steel casing having a magnetic susceptibility of about 6,700×

10⁶ or less and wherein the internal electrical battery components, the housing, the first and second electrically conductive paths and the lamp have magnetic susceptibilities at least as low as that of austenitic stainless steel.

16. The flashlight of claim 15 wherein the first electrically conductive path comprises the first spring intermediate the first and second electrically conductive rods.

17. The flashlight of claim 15 wherein the housing is of an acetal compound.

18. The flashlight of claim 15 wherein the first electrically conductive path is either of brass or beryllium copper.

19. The flashlight of claim 15 wherein the second electrically conductive path is either of brass or beryllium copper.

20. The flashlight of claim 15 wherein at least an external portion of at least one of the first and the second electrically conductive paths is comprised of beryllium copper plated with a material selected from the group consisting of chrome, titanium nitride and parylene, and mixtures thereof.

21. The flashlight of claim 15 wherein the battery is an alkali metal battery.

22. The flashlight of claim 15 wherein the battery is a lithium/thionyl chloride-bromine chloride battery.

23. The flashlight of claim 15 as a penlight.

24. A method for assembling a flashlight, comprising the steps of:

a) providing a housing;

b) housing a lamp inside the housing as a light source;

c) providing a battery inside the housing to electrically energize the lamp, wherein the battery has a first terminal and a second, opposite polarity terminal;

d) providing a first electrically conductive path connecting between the first terminal and the lamp; and

e) providing a second electrically conductive path connecting between the second terminal and the lamp, wherein when at least one of the first and second electrically conductive paths is open, the lamp is in an unenergized state and wherein when the at least one open conductive path is closed, the first and second electrically conductive paths are completed to thereby energize the lamp, and wherein at least one of the first and second electrically conductive paths comprise at least a first spring intermediate either a first and second electrically conductive rods or a first and second electrically conductive sleeves extending between the lamp and one of the first and second terminals of the battery.

25. The method of claim 24 including providing at least a portion of the first and the second electrically conductive path of brass.

26. The method of claim 25 including providing the brass composed of, by weight, about 62 to 65% copper, <

0.02% cadmium, <

0.03% iron, <

0.03% lead, <

0.03% tine, remainder zinc.

27. The method of claim 24 including providing the first electrically conductive path comprising the first spring intermediate the first and second rods.

28. The method of claim 24 including providing the second electrically conductive path comprising a second spring intermediate the first and second sleeves.

29. The method of claim 24 including providing the first electrically conductive path comprising the first spring intermediate the first and second rods, and the second spring intermediate the first and second sleeves.

30. The method of claim 29 including substantially radially aligning the first spring with the second spring.

31. The method of claim 29 including providing the first and the second springs as coil springs.

32. The method of claim 29 including disposing a non-conductive member between the first electrically conductive path comprising the first spring and the first and the second rods, and the second electrically conductive path comprising the second spring and the first and the second sleeves.

33. The method of claim 24 including providing the battery as an alkali metal battery.

34. A method for assembling a flashlight, comprising the steps of:

a) providing a housing;

b) housing a lamp inside the housing as a light source;

c) providing a battery housed inside the housing to electrically energize the lamp, wherein the battery has a first terminal and a second, opposite polarity terminal;

d) providing a first electrically conductive path connecting between the first terminal and the lamp; and

e) providing a second electrically conductive path connecting between the second terminal and the lamp, wherein when at least one of the first and second electrically conductive paths is open, the lamp is in an unenergized state and wherein when the at least one open conductive path is closed, the first and second electrically conductive paths are completed to thereby energize the lamp, and wherein at least one of the first and second electrically conductive paths comprise at least a first spring intermediate either a first and second electrically conductive rods or a first and second electrically conductive sleeves extending between the lamp and one of the first and second terminals of the battery, wherein the battery is an alkali metal battery sealed inside of an austenitic stainless steel casing having a magnetic susceptibility of about 6,700×

10⁶ or less and wherein the internal electrical battery components, the housing, the first and second electrically conductive paths and the lamp have magnetic susceptibilities at least as low as that of austenitic stainless steel.

35. The method of claim 34 including providing the first electrically conductive path comprising the first spring intermediate the first and second electrically conductive rods, and the second electrically conductive path comprises a second spring intermediate the first and second electrically conductive sleeves.

36. The method of claim 34 including providing the housing of an acetal compound.

37. The method of claim 34 including providing the first electrically conductive path of either brass or beryllium copper.

38. The method of claim 34 including providing the second electrically conductive path of either brass or beryllium copper.

40. The method of claim 34 including providing the battery as an alkali metal battery.

39. The method of 34 including providing at least an external portion of at least one of the first and the second electrically conductive paths comprised of beryllium copper plated with a material selected from the group consisting of chrome, titanium nitride and parylene, and mixtures thereof.