Jumper cables for sparkling polarity indicator

• US 3,936,121 A
• Filed: 08/19/1974
• Issued: 02/03/1976
• Est. Priority Date: 08/19/1974
• Status: Expired due to Term

• Current Assignee: Gerhard Karl Leinberger
• Original Assignee: Gerhard Karl Leinberger
• Inventors: Leinberger, Gerhard Karl
• Primary Examiner(s): McGlynn, Joseph H.
• Application Number:
  US05/498,391
• Time in Patent Office: 533 Days
• Field of Search: 339/28, 339/29, 339/113, 339/147, 339/255 P, 339/260, 339/261, 339/224, 136/181, 136/182, 320/25, 340/249
• US Class Current: 439/489
• CPC Class Codes: H01R 11/24 with gripping jaws, e.g. crocodile clip
• CPC Class Codes: Y10S 320/15 Polarity control

Abstract

Jumper cables or battery charging cables for automotive use and the like are disclosed in which at least one of the cable'"'"'s gripper jaws or clamps is provided with a length of coiled heater-resistance wire. The length of wire is clamped to the portion of the jaw handle opposite that to which the jumper cable wire itself is connected, and extends a short distance outwardly of the handle. The coiled heater-resistance wire is chosen as to have a preferred resistance in the order of 0.5 to 2 ohms and has an exposed free end which may be contacted to the battery terminal prior to connecting the gripper jaws to the terminal to indicate whether the charger cables have been correctly or incorrectly connected. If the connection is incorrect, the resistance wire will sparkle visibly and safely at the point of contact with the terminal, thus indicating the the connection is wrong. If no visible sparkle is seen then the charger cables may be clamped with the knowledge that the connection is correct and safe.

Claims

1. In jumper cables for connection between a pair of storage batteries for applying temporary power from a host battery to a receiving battery, the improvement in polarity detection comprising a gripper jaw having a pair of handle portions and in which one of the connecting cables is attached to one of said portions, a length of coiled resistance wire attached to the other of said handles, said length of wire being essentially self-supporting and extending outwardly of said handle and terminating in an exposed end and having a resistance with the handle in the other of 0.5 ohm to 4 ohms, the end of said wire providing a testing point which sparkles when touched to a battery terminal in which the jumper cables have been incorrectly connected to provide a visual indication of such incorrect connection.

2. A polarity indicator from jumper cables, battery chargers, and the like comprising a battery terminal-engaging clamp, a length of essentially rigid, self-supporting resistance rod attached to said clamp and having an exposed end extending therefrom adapted to be brought into contact with a battery terminal apart from said clamp, said rod being electrically connected to said clamp and having an effective resistance with said clamp in the order of 0.5 ohm to 4 ohms to provide a sparkling effect when the end thereof is touched to the battery terminal if the cables are incorrectly connected while limiting the current under such conditions to prevent damage to the battery and to prevent welding thereof to the terminal.

3. The indicator of claim 2 in which said rod comprises a length of coiled metallic resistance wire.

4. The indicator of claim 2 in which said clamp has a handle portion and a clamping jaw, and in which said rod extends as an effective continuation of said handle portion in a direction remote from said jaw, and an insulating sleeve surrounding said handle portion but exposing said end of said length of rod.