US3654824A

US3654824A - Fuse extractor unit

Info

Publication number: US3654824A
Application number: US18670A
Authority: US
Inventors: James M Reed
Original assignee: Littelfuse Inc
Current assignee: Littelfuse Inc
Priority date: 1970-03-11
Filing date: 1970-03-11
Publication date: 1972-04-11
Anticipated expiration: 1989-04-11

Abstract

A fuse extracting unit comprising an elongated body made of insulating materials and having a handle portion to be grasped by one hand of the user and a fuse grasping portion at each end thereof, each fuse-grasping portion having a fuse-receiving aperture extending through the body and adapted to receive the fuse therein, the aperture extending to one lateral side of the body to provide a lateral entryway to the aperture.

Description

United States Patent Reed [15] 3,654,824 [4 Apr.1l, 1972 [54] FUSE EXTRACTOR UNIT 3,215,006 11/1965 Urani ..8l/3.8

1,429,852 9/1922 Dyer et al. ..81/3.8

FOREIGN PATENTS OR APPLICATIONS 138,687 9/1950 Australia ..24/137 Primary Examiner-Theron E. Condon Assistant Examiner-Roscoe V. Parker, Jr. Attorney-Wallenstein, Spangenberg, I-lattis & Strampel [5 7] ABSTRACT A fuse extracting unit comprising an elongated body made of insulating materials and having a handle portion to be grasped by one hand of the user and a fuse grasping portion at each end thereof, each fuse-grasping portion having a fuse-receiving aperture extending through the body and adapted to receive the fuse therein, the aperture extending to one lateral side of the body to provide a lateral entryway to the aperture.

10 Claims, 5 Drawing Figures FUSE EXTRACTOR UNIT This invention relates to fuse extracting devices having as their principal use the insertion or removal of conventional cylindrical type fuses into or from spring metal anchoring clips.

In automotive vehicles and the like, fuses of the kind described are commonly mounted in deep channels of a support frame made of insulating material to minimize the possibility of short circuits between the spring metal clips secured in the channels. Because of the limited clearance spaces involved, an individual fuse is inserted into or removed from the anchoring clips by a tool sometimes referred to as a fuse extractor. One common form of fuse extractor comprises a body of insulating material having at each end thereof a pair of closely spaced laterally confronting fuse-receiving jaws opening onto the end of the extractor and of a width to accommodate a long or a short fuse. A typical fuse comprises a cylindrical glass body containing a fuse filament visible through the body with a pair of terminal-forming end caps extending around and closing off the ends of the cylindrical glass body. The jaws of the fuse extractor engage the portion of the fuse body between the terminal-forming end caps thereof. Since the fuse must be generally pulled from fuse anchoring clips snugly extending around the end caps thereof, it is most desirable that the fuse grasping portion of the extractor tightly encompass as long an axial extent of the fuse body as possible. For this reason, fuse extractors generally have a narrow fuse grasping portion for grasping the relatively short cylindrical bodies of low amperage fuses, and a much wider fuse grasping portion for grasping the longer fuse bodies of higher amperage rating. The jaws of these fuse extractions are separated (often with difficulty) by pushing the same longitudinally over the fuse involved so the pressure on the jaws separates the same. These fuse extractors further have a metal jaw-locking member which is movable along the body of the extractor to a point where it holds the jaws in a closed position so that the user may remove the fuse from its tightly held position in the anchoring clips by pulling the extractor longitudinally away from its anchoring clips.

These prior art fuse extractors leave much to be desired from the standpoint of the complexitythereof and the inconvenient manual manipulations required to open and lock the jawsof the extractor. Also, the use of a metal jaw locking member is dangerous when used in inserting fuses into or removing fuses from television set chassis and the like having high voltages.

The present invention provides a fuse extractor which is of simple, safe and economical construction and is much easier to utilize than the prior art fuse extractors. Thus, in accordance with one of the features of the invention, the extractor is designed so that it can be made as a single molded piece of insulating material which does not require any jaw locking partsor the like as in the above described fuse extractor. In the most preferred and advantageous form of the invention, the fuse extractor comprises an elongated body of insulating material having at each end thereof a fuse grasping portion for grasping a fuse of a relatively small or large amperage rating. The fuse grasping portion at each end of the extractor body has a fuse-receiving aperture which opens onto a lateral side of the fuse body through an entryway which is smaller than the diameter of the fuse. The fuse extractor is snapped around a fuse-by the simple expedient of moving the fuse grasping end portion of the extractor body to a position where the entryway of the fuse-receiving aperture faces the fuse body and then pushing the fuse grasping portion of the extractor over the fuse body preferably while rotating the extractor slightly forwardly. The fuse can then be simply removed from the fuse anchoring clips without the need of any jaw locking means by pulling the extractor body longitudinally thereof. The fuse can easily be released from the anchoring clips thereof without the need of any jaw locking means since the front portion of the fuse grasping portion of the fuse extractor forms a solid wall behind the fuse unlike the prior fuse extractors where the entryway into the jaws thereof is longitudinally rather than laterally of the fuse extractor body.

in accordance with another feature of the present invention, the entryway into the fuse-receiving aperture at each end of the extractor body is relatively large and is defined by front and rear outwardly diverging fuse guiding surfaces. Also, the fuse grasping portion preferably has a relatively thin curved finger-like wall defining the front half of the fuse-receiving aperture so that the front end of each fuse grasping portion of the extractor can fit between a relatively small clearance space between the fuse body and an insulting wall of a channelled fuse support frame as described.

In accordance with still another feature of the invention, the fuse extractor preferably has a laterally inwardly depressable arm extending longitudinally away from the rear side of the entryway into each fuse-receiving aperture, so that depression of the arm increases the size of the entryway to enable the easy separation of the fuse from the extracn'ng unit when the fuse has been removed from its anchoring clips.

The above and other features of the present invention will become apparent upon making reference to the specifications to follow the claims and the drawings wherein:

FIG. 1 is a plan view, partly broken away, of the fuse extractor constituting the preferred form of the present invention;

FIG. 2 is an elevational view, partly broken away, of the fuse extractor of FIG. 1;

FIG. 3 is a fragmentary plan view of a fuse support frame of the type frequently used in automobiles and the like, showing relatively large and relatively small fuses mounted in insulating channels of the frame;

FIG. 4 is a sectional view through the fuse mounting frame of FIG. 3, taken along section line 33 therein, and showing in solid lines the extractor of FIGS. 1 and 2 being applied to a fuse and in dashed lines the extractor snapped into place around the fuse; and

FIG. 5 is a view showing in solid lines a fuse extractor applying a fuse to the fuse support frame of FIG. 3 and in dashed lines showing the fuse extractor being released from the mounted fuse.

The fuse extractor of the invention shown in the drawing and identified by reference numeral 2 is a single piece molded synthetic plastic part having a narrow elongated shape in both longitudinal and vertical sections. While the shape of the fuse extractor may vary widely in accordance with the broadest aspect of the invention, it most advantageously has the shape illustrated in the drawings. The fuse extractor thus has a main body portion 2a forming a handle portion for the extractor and fuse grasping portions 2b and 2c at the opposite ends thereof adapted to engage respectively a relatively long fuse 3 and a relatively short fuse 3 (See FIG. 3). In the preferred form of the invention, the fuse extractor has spaced vertical longitudinal margins 4-4 on the opposite sides of the fuse which are in respective spaced, parallel, vertical planes, as best viewed in FIG. 1. The fuse grasping portion 2b adapted to grasp a relatively long fuse 3 extends for the full width of the fuse extractor between the vertical longitudinal margins 4-4. The fuse-grasping portion 2c adapted to grasp a relatively short fuse 3' is centered along the axis of the fuse extractor body and has opposite vertical longitudinal margins 8-8 spaced inwardly of the aforementioned vertical longitudinal margins 4- 4.

The fuse-grasping portion 2b for grasping relatively long fuses 3 has a fuse-receiving aperture 9 extending transversely between the vertical longitudinal margins 4-4' of the fuse extractor body. The fuse-grasping portion 2c for grasping relatively short fuses 3' has a fuse-receiving aperture extending transversely between the vertical longitudinal margins 8-8 of the fuse extractor body. The fuse-receiving apertures 9-9 are circular and open onto the lateral side of the fuse extractor body as viewed in FIG. 2 through relatively large entryways 9a9aa.-. The fuse-receiving apertures 9-9 most advantageously have a diameter slightly less than the diameter of the fuses 3-3 which have identical diameters but different axial lengths. The aperture entryways 9a-9aare defined by outwardly diverging front and rear surfaces Ila-13a and lla'-l3a'respectively of the fuse extractor body. The

entryways 9a-9aat their narrowest point are smaller than the diameter of the fuses 3-3. For example, the minimum width of the entryways 9a-9a'may be about 0.200 inches and the diameter of the fuse-receiving apertures 9-9 may be about 0.220 to 0.222 inches to accommodate a fuse diameter of about 0.223 inches.

The portion of the fuse body which contains the front end portions of the fuse-receiving apertures 9-9' are respectively formed by thin walled sections -15 which form narrow rounded finger-like extensions fittable in small clearance spaces.

The main body portions 2a of the fuse extractor body has a relatively long cavity 17 formed therein which opens onto the vertical longitudinal side margin 4 of the fuse extractor body. The cavity 17 defines the margins of a vertical wall 19 adjacent in part and extending along in part to the vertical longitudinal margin 4' of the fuse body, a bow shaped bottom wall 21 and an upper wall 23 having a protuberant central portion 24. The main body portion 2a has a pair of longitudinally extending, laterally inwardly depressible arms 26-26 which extend from the portion of the fuse body defining the rear surfaces l3a-13a'of the entryways 9a-9a'and terminate short of the protuberant portion 24. The arms 26-26 as illustrated extend the full width of the fuse extractor body and are spaced from the upper wall 23 so the arms can be depressed inwardly. When the arms 26-26' are respectively depressed inwardly, the portion of the fuse body defining the rear portions of the entryways 9a-9a' and the fuse-receiving apertures 9-9' deflect as indicated by the dash lines in FIG. 2 to widen or increase the size of the entryways 9a-9a' and the apertures 9-9 to permit the easy release of a fuse from the fuse-receiving apertures. The protuberant portion 24 of the upper wall 23 forms a convenient gripping portion along with the outer surface 21 of the wall 21 during the application of the fuse extractor to a fuse mounted within a fuse support frame or during the pulling of a fuse from the frame.

The fuse extractor 2 shown in FIGS. 1 and 2 is particularly useful for inserting fuses into and removing fuses from a fuse support frame 27 shown in FIGS. 3-5. The fuse support frame 27 has a number of closely spaced parallel walls 30. Fuses like 3, 3, etc. are supported in deep channels formed between the walls 30. The fuses illustrated are conventional type fuses including cylindrical glass housings 31 and 31' respectively containing individual fuse filaments 34 and 34' visible through the housings, and terminal-forming

end caps

33 and 33. The fuse 3' has end caps 33' spaced closely together, leaving only a very narrow glass surface to be engaged by the fuse grasping portion of the fuse extractor. The fuse 3 has a relatively large spacing between the end caps 33 thereof. Accordingly, since it is desirable to have a maximum gripping surface area between the fuse extractor and the fuse involved, the relative wide fuse grasping portion 2b of the fuse extractor is utilized for fuses wide enough to accommodate the same and the relatively narrow fuse grasping portion of the fuse extractor is used only with very short fuses.

Each fuse is anchored to the fuse support frame 27 by conventionally constructed anchoring clips 35 which are open at the top thereof and tightly clasp the end caps of the fuse involved so that an appreciable force is necessary to pull a fuse from the anchoring clips. The spaced parallel walls 30 of the fuse support frame 27 for most of the length thereof extend outwardly a substantial distance beyond the fuses and the anchoring clips so that short circuiting between the fuses is difficult to achieve. To permit access of a fuse extractor to each fuse, slots 32 are formed in the walls 30 opposite the

glass housings

31 or 31 of the fuses involved to permit access to the fuses. The width of the wide fuse grasping position 2b is slightly smaller than the width of the slots 32.

When it is desired to extract a relatively wide fuse 3 from the fuse support frame 27, the wide fuse grasping portion 2b is placed in position within one of the wall slots 32 with the thinwalled curved finger 15 thereof fitting into the narrow space between the fuse and the adjacent insulating wall 30. The user then pushes the fuse grasping portion toward the fuse while rotating the same slightly in a direction to bring the finger 15 further behind the fuse. In so doing, the flexibility of the synthetic plastic material out of which the fuse grasping portion 2b is made causes the same to snap into position so the defining surface of the fuse-receiving aperture 9 snugly engages the glass housing 31 of the fuse 3. The fuse then can be extracted by simply pulling the fuse extractor in a direction longitudinally thereof so the finger 15 thereof applies a withdrawing force to the fuse which removes the same simultaneously from the associated clips 35. The fuse can then be simply manually removed from the fuse-receiving aperture 9 by pulling the fuse from the fuse extractor or the extractor from the fuse. This removal operation is simplified if the user depresses the arm 26 adjacent the fuse grasping position 2b to increase the size of the fuse-receiving aperture 9 and the entryway 9a thereto in the manner illustrated by the dashed line portion of FIG. 2.

When inserting a fuse into a pair of fuse clips 35 within the fuse support frame, the fuse extractor is moved between the walls 30 involved as shown in solid lines in FIG. 5 and then pushed toward the fuse support frame to bring the end caps of the fuse involved into the associated clips 35. The fuse extractor can then be simply removed from the fuse by pushing or rocking the same on the wall 30 so as to caUse the fuse grasping portion 2b at the forward end thereof to move laterally upwardly to pull the same laterally from the fuse.

It is apparent that the present invention has provided an exceedingly simple economical and shock-hazard free extractor for mounting fuses into or removing fuses from fuse anchoring clips where small clearances are provided for the extractor.

It should be understood that numerous modifications may be made in the most preferred form of the invention described above, without deviating from the broader aspects of the invention.

I claim:

1. A fuse extracting unit for pulling a fuse from a pair of fuse terminal anchoring clips, the unit comprising: a body made of insulating material having a handle portion to be grabbed by one hand of the user and a flexible resilient fuse grasping portion at one end thereof, the fuse grasping portion of the unit having a fuse-receiving aperture extending through the body and adapted to receive a fuse therein, the aperture extending to one lateral side of the body to provide a lateral entryway to the aperture which entryway is of a size smaller than the diameter of the fuse, the portion of said body defining the front portion of said fuse-receiving aperture being a relatively thin, short, finger-like projection fittable in a small space between a cylindrical fuse supported in said fuse anchoring clips and a closely positioned insulating wall where it can be applied around the fuse, said fuse grasping portion of said body being so flexible and resilient that said entryway readily expands to snap the fuse grasping portion of the body in place around the fuse when the latter portion of the body is pushed over the fuse with the entryway facing the fuse, the subsequent pulling of the body longitudinally away from the fuse effecting removal of the fuse from the fuse anchoring clips 2. The fuse extracting unit of claim 1 wherein said aperture entryway is relatively large and defined by laterally outwardly diverging front and rear surfaces.

3. The fuse extracting unit of claiml wherein said body of the fuse extracting unit has a lever-forming arm extending longitudinally away from the inner side of the entryway of said fuse-receiving aperture and being spaced from and being thin relative to the adjacent portion of the body of the fuse extracting unit so squeezing the lever-forming arm and said adjacent body portion will cause the arm to flex inwardly and increase the size of the entryway to enable the easy removal of the fuse extracting unit from the extracted fuse, and the body of the fuse extracting unit at least in the region of said depressible arm is of a size to be grasped with the arm and squeezed to flex said am.

4. The fuse extracting unit of claim 3 wherein said handle portion of the body extends longitudinally beyond the end of said depressible lever-forming arm.

5. The fuse extracting unit of claim 3 wherein said entire unit is a single integrally molded synthetic plastic piece.

6. A fuse extracting unit for pulling a fuse from a pair of fuse terminal anchoring clips, said unit comprising an elongated body of insulating material having at each end thereof a resilient flexible fuse grasping portion for grasping fuses of different sizes, a portion of the elongated body located longitudinally inwardly of each fuse grasping portion thereof serving as a handle to be grasped while the fuse grasping portion thereof is applied to a fuse, each fuse grasping end portion of the elongated body of the fuse extracting unit having a fusereceiving aperture extending through the body and adapted snugly to receive a fuse therein, the aperture extending to one lateral side of the body to provide a lateral entryway to the aperture which entryway is of a size smaller than the diameter of the fuse, the fuse grasping portion of the body being so flexible and resilient that said entryway readily expands and the fuse grasping portion of the body snaps in place around the fuse when the same is pushed over the fuse with the entryway facing the fuse, the subsequent pulling of the body longitudinally away from the fuse effecting removal of the fuse from the fuse anchoring clips.

7. The fuse extracting unit of claim 6 wherein said elongated body of the fuse extracting unit has at each end thereof a laterally inwardly depressible lever-forming arm extending longitudinally inwardly away from the inner side of the entryway of the adjacent fuse-receiving aperture so depression of the arm increases the size of the entryway to enable the easy removal of the fuse extracting unit from the extracted fuse.

8. The fuse extracting unit of claim 6 wherein the fuse grasping end portions at the opposite ends of the elongated body have different thicknesses in a direction parallel to the axis of the fuse-receiving apertures to provide a more rigid and greater grasping area for the larger fuse.

9. The fuse extracting unit of claim 7 wherein the axis of the fuse-receiving apertures are parallel and the elongated body thereof is relatively thin with said depressible arms being generally coplanar extensions thereof.

10. The fuse extracting unit of claim 7 wherein the entire unit is a single integrally molded synthetic plastic piece.

* i t I.

Claims

1. A fuse extracting unit for pulling a fuse from a pair of fuse terminal anchoring clips, the unit comprising: a body made of insulating material having a handle portion to be grabbed by one hand of the user and a flexible resilient fuse grasping portion at one end thereof, the fuse grasping portion of the unit having a fuse-receiving aperture extending through the body and adapted to receive a fuse therein, the aperture extending to one lateral side of the body to provide a lateral entryway to the aperture which entryway is of a size smaller than the diameter of the fuse, the portion of said body defining the front portion of said fuse-receiving aperture being a relatively thin, short, fingerlike projection fittable in a small space between a cylindrical fuse supported in said fuse anchoring clips and a closely positioned insulating wall where it can be applied around the fuse, said fuse grasping portion of said body being so flexible and resilient that said entryway readily expands to snap the fuse grasping portion of the body in place around the fuse when the latter portion of the body is pushed over the fuse with the entryway facing the fuse, the subsequent pulling of the body longitudinally away from the fuse effecting removal of the fuse from the fuse anchoring clips.

2. The fuse extracting unit of claim 1 wherein said aperture entryway is relatively large and defined by laterally outwardly diverging front and rear surfaces.

3. The fuse extracting unit of claim 1 wherein said body of the fuse extracting unit has a lever-forming arm extending longitudinally away from the inner side of the entryway of said fuse-receiving aperture and being spaced from and being thin relative to the adjacent portion of the body of the fuse extracting unit so squeezing the lever-forming arm and said adjacent body portion will cause the arm to flex inwardly and increase the size of the entryway to enable the easy removal of the fuse extracting unit from the extracted fuse, and the body of the fuse extracting unit at least in the region of said depressible arm is of a size to be grasped with the arm and squeezed to flex said arm.

6. A fuse extracting unit for pulling a fuse from a pair of fuse terminal anchoring clips, said unit comprising an elongated body of insulating material having at each end thereof a resilient flexible fuse grasping portion for grasping fuses of different sizes, a portion of the elongated body located longitudinally inwardly of each fuse grasping portion thereof serving as a handle to be grasped while the fuse grasping portion thereof is applied to a fuse, each fuse grasping end portion of the elongated body of the fuse extracting unit having a fuse-receiving aperture extending through the body and adapted snugly to receive a fuse therein, the aperture extending to one lateral side of the body to provide a lateral entryway to the aperture which entryway is of a size smaller than the diameter of the fuse, the fuse grasping portion of the body being so flexible and resilient that said entryway readily expands and the fuse grasping portion of the body snaps in place around the fuse when the same is pushed over the fuse with the entryway facing the fuse, the subsequent pulling of the body longitudinally away from the fusE effecting removal of the fuse from the fuse anchoring clips.