Inductive pickup clip

• US 4,234,863 A
• Filed: 11/08/1978
• Issued: 11/18/1980
• Est. Priority Date: 11/08/1978
• Status: Expired due to Term

• Current Assignee: Dixson, Inc. (Ametek Incorporated)
• Original Assignee: Dixson, Inc. (Ametek Incorporated)
• Inventors: Shumway, DeWayne J., Gennetten, Delbert D.
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US05/958,748
• Time in Patent Office: 741 Days
• Field of Search: 336/175, 336/176, 336/90, 336/92, 324/127, 324/149, 324/117 R, 324/117 H, 324/129, D10/79, 335/193, 335/46, 335/104, 335/248, 335/271, 335/277, 335/257
• US Class Current: 336/90
• CPC Class Codes: G01R 1/06 Measuring leads; Measuring probes G01R19/145, G01R19/165 take precedence
• CPC Class Codes: G01R 15/186 using current transformers with a core consisting of two or more parts, e.g. clamp-on type G01R15/142 - G01R15/16 take precedence; tong testers G01R1/22
• CPC Class Codes: G01R 19/15 Indicating the presence of current
• CPC Class Codes: H01F 38/30 Constructions

Abstract

An inductive pickup clip comprising two telescoping body portions between which is compressed a main body spring and within which are mounted respective core portions. When the clip is closed, said core portions define an opening adapted to receive therethrough an electric wire during use. The end portions of at least one core portion are spring loaded to prevent chipping or breakage of the core portions and to insure correct alignment of the cores when the clip is closed. A bi-stable latching mechanism is employed which, when latched, holds the clip closed, and when unlatched, permits the spring loaded telescoping body portions to assume an open configuration under the urging of the main body spring therebetween. Such a latching mechanism insures that when the slip is closed about the electric wire to be monitored, the user must close it against the force of the main body spring, thereby further preventing chipping or breakage of the core portions. Said telescoping body portions also include complementary guides which insure that when said telescoping body portions are urged together by the user, they will be brought together in a direction which will help to insure a snug fit and correct alignment therebetween, and which will help to prevent damage to the core portions.

Claims

1. An inductive pickup clip for generating an output signal in response to changes in the flow of electric current in an electric conductor about which said clip is adapted to be removably secured, wherein said clip is of the type including:

first and second body portions having first and second core portions secured thereto respectively, wherein said first body portion is held telescopically within said second body portion; and

a pickup coil means positioned about one of said core portions and having terminals adapted to be connected to an electrical circuit;

wherein said body portions, and hence said core portions, are telescopically selectively movable with respect to each other between an open configuration and a closed configuration in which said core portions fit together to define an opening adapted to receive said electric conductor during use, and

wherein the improvement comprises;

shock absorbing means located only at the end portions of at least one of said core portions and being secured between said at least one of said core portions and its respective body portion for cushioning said at least one core portion as said core portions are moved into contact with each other in said closed configuration, to prevent chipping or breaking of said core portions and to insure a close fit and correct alignment between said core portions when in said closed configuration.

2. The inductive pickup clip according to claim 1, wherein said shock absorbing means comprises a pair of interconnected springs spaced apart a distance approximately equal to the distance between the end portions of said at least one core portion, to insure said springs will always load its said end portions, and not its central portion, thereby eliminating the need for a separate support for said at least one core portion while still providing shock absorbing support for the ends of said at least one core portion.

3. The inductive pickup clip according to claim 2, wherein said shock absorbing means comprises at least one length of wire having a substantially straight middle spacing segment and being wound to form a spring at each of its ends, wherein the length of said straight segment is selected to space apart the springs it forms at each of its ends a distance about equal to the distance between said end portions of said at least one core portion, to ensure said springs will always load said end portions of said core portions.

4. The inductive pickup clip according to claim 1, wherein only one of said core portions has said shock absorbing means, and the core portion which does not carries said pickup coil means.

6. The inductive pickup clip according to claims 1 or 5, wherein at least one of said core portions is retained within its respective body portion by a retainer secured to said respective body portion, said retainer being so located to also insulate said at least one core portion from said electric wire which may pass through said opening defined by said core portions when they are in said closed configuration.

7. The inductive pickup clip according to claims 1 or 5, wherein said spring means is a spring under compression loading which normally tends to urge said body portions to maintain said open configuration and wherein the user must force said body portions from said open configuration into said closed configuration against the urging of said spring.

8. The inductive pickup clip according to claims 1 or 5, wherein said first body portion defines a first cavity within which said spring is located, and wherein one end of said spring pushes against an interior portion of said first body portion.

9. The inductive pickup clip according to claims 1 or 5, wherein said second body portion defines a plurality of alignment channels and said first body portion defines a plurality of alignment ribs received by said channels and wherein none of said alignment ribs protrude from said second body portion, in order to provide a pickup clip less likely to entangle with the wiring it may be used near.

10. The inductive pickup clip according to claims 1 or 5, wherein that portion of said first body portion which carries said first core portion is located substantially exteriorly of said second body portion.

11. The inductive pickup clip according to claims 1 or 5, wherein said pickup clip further comprises latch means to releaseably hold said body portions in said closed, working configuration despite the urging of said spring means.

12. The inductive pickup clip according to claim 11, wherein said latch means comprises a bi-stable latching mechanism means which automatically engages when said body portions are squeezed together into said closed configuration and which automatically disengages when said body portions are squeezed together still further and then released.

13. The inductive pickup clip according to claim 12, wherein said bi-stable latching mechanism comprises a latching arm secured to and carried by said first body portion and further comprises a tortuous loop path carried by said second body portion, wherein one end of said latching arm travels in said tortuous loop path and the whole latching arm is located within said second body means.

14. The inductive pickup clip according to claim 6, wherein each of said body portions includes a retainer portion, the retainer portion for said first body portion being flat and elongated and the retainer portion for said second body portion being generally u-shaped, both retainer portions extending outwardly from one sidewall of its respective body portion, and wherein when said pickup clip is in said closed configuration said retainer portions define an insulated hole adapted to receive said wire during use of said pickup clip.

5. An inductive pickup clip for generating an output signal in response to changes in the flow of electric current in an electric conductor about which said clip is adapted to be removably secured, wherein said clip is of the type including:

first and second body portions having first and second core portions secured thereto respectively;

a pickup coil means positioned about one of said core portions and having terminals adapted to be connected to an electrical circuit; and

spring means connected between said body portions;

wherein said body portions, and hence said core portions, are telescopically selectively movable with respect to each other between an open configuration and a closed, working configuration in which said core portions fit together to define an opening adapted to receive said electric conductor during use; and

wherein the improvement comprises;

said spring means being arranged to urge said body portions towards said open configuration, meaning the user of said clip must work against the urging of said spring means to force said body portions from said open configuration into said closed, working configuration.