US3723931A

US3723931A - Protectors for electric circuits

Info

Publication number: US3723931A
Application number: US00163889A
Authority: US
Inventors: A Urani
Original assignee: McGraw Edison Co
Current assignee: Cooper Industries LLC
Priority date: 1971-07-19
Filing date: 1971-07-19
Publication date: 1973-03-27
Anticipated expiration: 1990-03-27

Abstract

A fuse carrier has a circuit-closing member that can be moved by the switch-actuating plunger of a fuse which is held by clips on that fuse carrier. A stop on that fuse carrier lies in the path of a protuberance on one terminal of that fuse, and thereby maintains a minimum distance between that terminal and that circuit-closing member. That stop also coacts with an abutment, within an elongated recess in the fuseholder for that fuse carrier, to keep that fuse carrier from being inserted into that recess while it is in its inverted position. A surface adjacent one of the clips and an open area adjacent the other of the clips on the fuse carrier coact with the protuberance on the one terminal of the fuse to keep that fuse from being fully seated within those clips unless that fuse is correctly oriented relative to the circuit-closing member.

Description

United States atent 1191 Urani 1 1 Mar. 27, 1973 [54] PROTECTORS FOR ELECTRIC FOREIGN PATENTS OR APPLICATIONS CIRCUITS 692,627 6/1953 Great Britain ..337/248 [75] Inventor: Angelo Urani, St. Louis, Mo.

Primary ExaminerBernard A. Gilheany [73] Ass1gnee: mcGraw-Edison Company, Elgm, Assistant Grimley Attorney-Edmund C. Rogers et al. [22] Filed: July 19, 1971 211 App]. No.: 163,889 [57] ABSTRACT A fuse carrier has a circuit-closing member that can [52] USC' 337/342 337/5 337/194 be moved by the switch-actuating plunger of a fuse 5 3 337/225 which is held by clips on that fuse carrier. A stop on [5l] Int. Cl. UHO Ih 37/74 that fuse carrier in the Path of a protuberance 58 Field of Search ..337/5,l42,143,147,148, one terminal of that fuse, and thereby maintains a 337/194, 195 196 201, 0 208, 210, 213 minimum distance between that terminal and that cir- 2l4, 215, 225, 226, 248, 241, 242, 244; cult-closing member. That stop also coacts with an 340/250 abutment, within an elongated recess in the fuseholder for that fuse carrier, to keep that fuse carrier from [56] References Cited being inserted into that recess while it is in its inverted position. A surface adjacent one of the clips and an UNITED STATES PATENTS open area adjacent the other of the clips on the fuse 3,304,391 2/1967 Linton ..337/206X Carrier C0301 wi h the protuberance on the one ter- 3,593,247 7/1971 Collins ..337/5 minal of the fuse to keep that fuse from being fully 2,855,483 10/1958 Swing et a]. ..337/206 X Seated within those clips unless that f is Correctly oriented relative to the circuit-closing member.

13 Claims, 16 Drawing Figures 76' //0 v k a .2 ve d". 4.4;. \"t

Patented March 27, 1973 3,723,931

2 Sheets-Sheet Z .I W W 11600! my x2 /6 /#2 Fl 6 l5 va 206 PROTECTORS FOR ELECTRIC CIRCUITS BACKGROUND OF THE INVENTION Electric fuses which are equipped with switch-actuating plungers are very useful when they are correctly oriented with respect to the fuse-receiving clips therefor. However, if such a fuse were to be given an orientation other than its correct orientation, the plunger of that fuse might be unable to provide the required actuation of the circuit-closing member which it is supposed to engage and move. To be correctly oriented, such a fuse must not only have the plunger thereof directed toward the circuit-closing member that it is intended to engage and move, but it must have that plunger spaced a predetermined distance from that switch-closing member.

SUMMARY OF THE INVENTION The present invention provides a fuse carrier which has clips that can receive and hold an electric fuse which is equipped with a switch-actuating plunger; and that fuse carrier has an obstructing surface adjacent one of those clips and a recess adjacent another of those clips. That recess can accommodate a protuberance on one of the terminals of that fuse, and thus can permit full seating of that fuse within those clips when that fuse is correctly oriented relative to those clips; but that obstructing surface will intercept that protuberance and thereby prevent full seating of that fuse within those clips when that fuse is not correctly oriented relative to those clips. As a result, the present invention keeps the fuse from being fully seated within the clips of the fuse carrier unless the plunger of that fuse is directed toward the circuit-closing member on that fuse carrier. It is, therefore, an object of the present invention to provide a fuse carrier with a circuit-closing member, with fuse-receiving clips, with an obstructing surface adjacent one of those clips, and with a recess adjacent the other of those clips, and to provide a fuse with a switch-actuating plunger carried by one terminal thereof and with a protuberance on the other terminal thereof which can engage the obstructing surface and thereby prevent full seating of the fuse within those clips unless that plunger is directed toward that circuit-closing member.

The fuse carrier provided by the present invention has a stop which is spaced from the circuit-closing member on that fuse carrier; and that stop will coact with the protuberance on the one terminal of the fuse to maintain a minimum distance between that one terminal and that circuit-closing member. In doing so, that stop will keep the switch-actuating plunger of the fuse from being positioned so close to that circuit-closing member that a premature movement of that circuitclosing member will occur. It is, therefore, an object of the present invention to provide a fuse carrier which has a stop thereon that will coact with a protuberance on one terminal of a fuse to maintain a minimum distance between that stop and a circuit-closing member on that fuse carrier thereby keeping the switch-actuating plunger of that fuse from prematurely moving that circuit-closing member.

The fuse carrier of the present invention is intended to telescope into an elongated recess within a fuseholder; and the fuse-receiving clips on that fuse carrier are dimensioned to fit within that recess whether that fuse carrier is in its normal or inverted position. However, contacts on that fuse carrier can electrically engage contacts within that recess only when that fuse carrier is telescoped into that recess while it is in its normal position. The present invention makes certain that the fuse carrier will not be telescoped into the elongated recess in the fuse holder while it is in its inverted position, by providing that fuse carrier with a stop which will engage and be held by an abutment within that fuseholder whenever that fuse carrier is in its inverted position. It is, therefore, an object of the present invention to provide a fuse carrier with a stop which will engage and be held by an abutment within an elongated recess in a fuseholder whenever that fuse carrier is in its inverted position.

Other and further objects and advantages of the present invention should become apparent from an examination of the drawing and accompanying descriptron.

In the drawing and accompanying description a preferred embodiment of the present invention is shown and described but it is to be understood that the drawing and accompanying description are for the purpose of illustration only and do not limit the invention and that the invention will be defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWING In the drawing, FIG. 1 is a plan view of one preferred embodiment of fuse carrier that is made in accordance with the principles and teachings of the present invention,

FIG. 2 is a side elevational view of the fuse carrier shown in FIG. 1,

FIG. 3 is a sectional view through the fuse carrier of FIGS. 1 and 2, and it is taken along the plane indicated by the line 3-3 in- FIG. 1,

FIG. 4 is a cross sectional view through the fuse carrier of FIGS. 1 and 2, and it is taken along the plane indicated by the line 4-4 in FIG. 2,

FIG. 5 is another cross sectional view through the fuse carrier of FIGS. 1 and 2, and it is taken along the plane indicated by the line 5-5 in FIG. 2,

FIG. 6 is a further cross sectional view through the fuse carrier of FIGS. I and 2, and it is taken along the plane indicated by the line 6-6 in FIG. 2,

FIG. 7 is yet another cross sectional view through the fuse carrier of FIGS. 1 and 2, and it is taken along the plane indicated by the line 77 in FIG. 3,

FIG. 8 is an additional cross sectional view through the fuse carrier of FIGS. 1 and 2, and it is taken along the plane indicated by the line 8-8 in FIG. 3,

FIG. 9 is a still further cross sectional view through the fuse carrier of FIGS. 1 and 2, and it is taken along the plane indicated by the line 9-9 in FIG. 3,

FIG. 10 is a sectional view, on a larger scale, through the fuseholder of FIGS. 1 and 2, and it is taken along the broken plane indicated by the broken line 10-40 in FIG. 2,

FIG. 11 is an end elevational view of a fuse holder into which the fuse carrier of FIGS. 1 and 2 can be telescoped,

FIG. 12 is an end view of the fuseholder of FIG. 11 and of the fuse carrier of FIGS. 1 and 2 after that fuse carrier has been telescoped into that fuseholder,

,plane indicated by the line 14l4 in FIG. 13,

FIG. 15 is a sectional view through parts of the fuse carrier and fuseholder of FIG. 12; it is taken along the plane indicated by the line l3-l3 in FIG. 12, and it shows the fuse carrier being inserted in its inverted position, and

FIG. 16 is a cross sectional view through the fuse carrier and fuseholder of FIG. 12, and it is taken along the plane indicated by the line 16-16 in FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing in detail, numeral 20 generally denotes a fuse carrier. which includes a generally L-shaped element 21 of insulating material.

That element has an elongated generally-triangular guiding surface 22 at one side thereof, and has an elongated generally-triangular guiding surface 24 at the opposite side thereof, as shown particularly by FIGS. 4-8. The element 21 has a portion 26 of reduced height adjacent the left-hand end thereof, as that element is viewed in FIGS. 2 and 3; and that portion defines an open area 27 above it. A vertically-directed opening 28 is formed in the reduced-height portion 26; and the lower end of that opening is contiguous with a largerdiameter recess 30 which opens to the bottom surface of the element 21. That element has a portion 32 which is thicker than the reduced-height portion 26, and which is spaced from that reduced-height portion by a still thicker portion 34. The portion 32 of element 21 is spaced from a reduced-height portion 38 by a thick portion 36. The sides of the

portions

32, 34 and 36 are inclined relative to the upper surfaces of those portions, as shown by FIG. 5. The reduced-height portion 26 and the thicker portion 34 coact to define a rightangle shoulder 37; and, similarly, the reduced-height portion 38 and the thicker portion 36 coact to define a right-angle shoulder 39. A vertically-directed opening 40 is formed in the reduced-height portion 38; and the lower end of that opening is contiguous with a largerdiameter recess 42 which opens to the bottom surface of the element 21.

A vertically-directed recess 44 is provided in the foot 46 of the L-shaped element 21; and that recess is generally-rectangular in plan while being generallytrapezoidal in elevation. A horizontally-directed opening 48 is provided in the foot 46; and the left-hand end of that opening communicates with the recess 44. Shallow

grooves

50 and 52 are formed in the confronting faces of the portions of the foot 46 which define the recess 44, as shown particularly by FIGS. 1, 3 and 7. The generally L -shaped insulating element 21 of the fuse carrier 20 can be made in various ways; but it preferably will be made by a compression molding process.

The numeral 54 denotes a metal terminal which is generally cup-shaped in configuration, as indicated by FIG. 3. That terminal has an opening 55 in the closed end thereof which has a diameter that is appreciably larger than the diameter of the opening 48 in the foot 46 of the generally L-shaped insulating member 21.

The terminal 54 has an outwardly-directed annular flange on the free edge thereof. The numeral denotes a spacing washer which is dimensioned to telescope within the opening 55 in the closed end of the terminal 54; and that washer is thicker than that closed end. An insulating washer 62 abuts the right-hand face of the spacing washer 60, and thus is held a small distance away from the inner face of the closed end of the terminal 54; and a washer 64 abuts the right-hand face of the insulating washer 62. A rivet 56 has the head thereof lodged within the recess 44 in the foot 46 of the generally L-shaped insulating member 21; and it has the stem thereof extending through the passage 48 in that foot, through the opening in the spacing washer 60, through the opening in insulating washer 62, and through the opening in the washer 64. The free end of that rivet is riveted over into intimate engagement with the right-hand surface of the rivet 64, and that free end has a recess 58 therein, all as indicated by FIG. 10.

Ears

66 and 68 are formed on, and project outwardly from, opposite sides of the terminal 54, as shown by FIG. 1.

Stops

70 and 72 are formed on, and project to the left from, the outer face of theterminal 54, as shown by FIGS. 1 and 10. As shown particularly by FIG. 8, the

stops

70 and 72 are close to the outer faces of the sides of the foot 46 of the generally L-shaped insulating member 21. The rivet 56, the spacing washer 60 and the insulating washer 62 coact with thatfoot to permit rotation of the terminal 54 about the axis of that rivet; but the

stops

70 and 72 limit the extent of that rotation. The

ears

66 and 68 act as contacts for the fuse carrier 20.

The numeral 74 denotes a knob of transparent plastic material which has a cylindrical end that is dimensioned to telescope within the cup-shaped terminal 54; and that knob has a radially-extending flange 76 intermediate the ends thereof which confronts, but is spaced a short distance outwardly of, the flange on the free edge of that terminal. An elongated recess 78 within the knob 74 is aligned with, but is considerably larger in diameter than, the rivet 56. A slot 80 is formed in the left-hand end of the knob 74, as shown particularly by FIGS. 3 and 9. Flat finger-receiving surfaces 82 are formed at opposite faces of the outer portion of the knob 74 as indicated by FIGS. l-3.

The numeral84 denotes a resistor which has one terminal thereof electrically bonded and mechanically secured to the rivet 56 by solder 86, as shown by FIG. 10. The numeral 88 denotes a lamp which has one terminal thereof wrapped around, and soldered to, the other terminal of the resistor 84; and that lamp has the lead 90 thereof extending through the slot 80 into the annular space defined by the flange 76 on knob 74 and the flange on the free edge of terminal 54. Solder or a weld will provide a good'electrical connection between the lead 90 and the terminal 54. Portions of the cylindrical wall of the terminal 54 are forced inwardly into holding engagement with the cylindrical portion of the knob 74, and one of those portions is indicated by the numeral 91 in FIGS. 1 and 2. A second of those portions, not shown, is located at the opposite end of the diameter on which the portion 91 lies. Those portions provide such a positive locking engagement between the knob 74 and the terminal 54 that the said knob and terminal rotate as a unit about the axis of the rivet 56. An Otring 92 of resilient material is disposed within the annular recess defined by the flange 76 on knob 74 and the flange on the free edge of terminal 54. As indicated by FIGS. 1-3, the outer surface of that O-ring normally projects radially outwardly beyond the outer surface of the flange 76 on the knob 74.

The numeral 94 denotes a flat metal plate which is generally T-shaped in front elevation, as indicated by FIG. 7; and the side edges of the cap" of that plate are disposed within the

grooves

50 and 52 in the foot 46, as indicated by FIGS. 1 and 7. The stem of the plate 94 extends downwardly through a passage 96 in the generally L-shaped element 21, as indicated particularly by FIG. 3; and the lower end of that stem is then widened to make that lower end wider than the passage 96, as shown by FIG. 7. The passage 96, the

grooves

50 and 52, and the widening of the lower end of the stern of the plate 94 fixedly hold that plate in position relative to the generally L-shaped insulating element 21. The lower end of that plate extends downwardly below the lower surface of the element 21 to act as a contact for the fuse carrier 20.

A horizontally-directed opening 98 is provided in the plate 96, as shown by FIGS. 3 and and a headed pin 100 is movably disposed within that opening. A generally cup-like cap 102 of insulating material is secured to the left-hand end of the pin 100, as indicated by FIGS. 1-3 and 10; and a helical compression spring 104 surrounds that pin, and has one'end there-of bearing against the right-hand face of that cap while having the other end thereof bearing against the left-hand face of the plate 94.

The numeral 106 denotes a stop which is L-shaped in elevation, as indicated by FIGS. 2 and 3; and that stop has a U-shaped slot 108 in the vertically-directed portion thereof, as indicated by FIGS 1, 4 and 5. That stop has an opening in the horizontally-directed portion thereof; and that opening is in register with the opening 28 in the reduced-height portion 26 of the element 21. A U-shaped fuse clip 110 of standard and usual design is secured to the element 21 and to the stop 106 by a rivet 112 which is lodged within the opening 28 in that element. Solder 114 is used to provide a good electrical connection between the stop 106 and the fuse clip 110. As indicated by FIGS. l-3, the free end of the horizontally-directed portion of the stop 106 projects outwardly beyond the left-hand end of the element 21 and beyond the left-hand edge of the fuse clip 110; and that free end of that stop acts as a contact for the fuse carrier 20.

The numeral 116 denotes a U-shaped metal terminal with outwardly bent ears 118; and a U-shaped fuse clip 120 of standard and usual design is disposed within that U-shaped terminal. That fuse clip and that terminal have openings in the bottoms thereof; and a rivet 122 is lodged within the opening 40 to mechanically secure that terminal and that fuse clip to the element 21. Solder 124 is used to provide a good electrical connection between the terminal 116 and the fuse clip 120. The ears 118 project laterally outwardly beyond the sides of the terminal 116 and act as contacts for the fuse carrier 20. p

The numeral 126 denotes an electric fuse of the enclosed cartridge type; and that fuse has a ferrule-like terminal 128 at the left-hand end thereof which has a bell-like flange 130 at the free edge thereof. A ferrulelike terminal 132 is provided at the opposite end of the fuse 126; and that terminal is equipped with a switchactuating plunger 134. That plunger normally is in the retracted position indicated by FIGS. 2 and 13-15; but it will move to the extended position shown by FIG 3 whenever the fusible element within the fuse 126 fuses.

The numeral generally denotes a fuseholder which has an elongated recess 157 therein that is dimensioned to receive the fuse carrier 20. The righthand end of that fuseholder has a plane surface 142 which is disposable immediately adjacent the rear face of a panel, not shown; and the numeral l44 denotes a resilient gasket which will be interposed between that surface and that rear face. A large diameter annular projection 146 and a small diameter annular projection 148 extend outwardly from the surface 142; and those projections will extend through suitable openings in the panel. Screws 150 will pass through further openings in that panel and will seat within threaded sockets 152 in the fuseholder 140 to secure that fuseholder to that panel.

The numeral 154 denotes a horizontally-directed opening in the rear wall of the fuseholder 140; and that opening accommodates the threaded shank of a movable contact 156 which has an enlarged head within the recess 157. That contact is one of the contacts of the fuseholder 140; and it is intended to receive the free end of the horizontally-directed portion of the stop 106. As indicated by FIG. 13, the front face of the en" larged head of the movable terminal 156 is concave. A short conductor 158 is disposed within the recess 157 in the fuseholder 140; and that conductor has an opening therein to accommodate a rivet 162. That rivet is lodged within an opening in the wall of the fuseholder 1'40, and it secures that conductor to that fuseholder and also to a solder lug 164. That solder lug and the outer end of the rivet 162 are disposed within an elongated groove 165 in the outer surface of that fuseholder. Solder will be applied to the solder lug 164 and to the rivet 162 to provide a good electrical connection between that solder lug and the conductor 158. A helical compression spring 166 encircles the threaded shank of the movable contact 156; and one end of that spring bears against the inner end of the recess 157, while the other end of that spring bears against the head of that movable contact. A nut 168, a lock washer 170, and a second nut 172 are threaded onto the threaded shank of the movable contact 156. The helical compression spring 166 biases that movable contact for movement to the right in FIGS. 13 and 14, but that spring can yield to permit that contact to be moved to the position shown in FIGS. 13 and 14.

The numeral 174 denotes an inverted U-shaped contact which is disposed within the recess 157 in the fuseholder 140, as shown particularly by FIGS. 11 and 16. The numeral 176 denotes an elongated terminal which has the left-hand end thereof threaded and which has the right-hand end thereof planished and provided with an opening therein. A rivet 178 extends through an opening in the closed end of the U-shaped contact 174, through an opening in the wall of the fuseholder 140, and through the opening in the planished end of the terminal 176; and that rivet electrically connects that U-shaped contact to the terminal 176 while mechanically securing that U-shaped contact and that terminal to the fuseholder 140. A conductor 180 is electrically connected to the right-hand end of the terminal 176, and it extends to the right from that terminal. As shown particularly by FIGS. 13 and 15, the right-hand end of the conductor 180 is disposed within the passage defined by the annular projection 148. That passage is small enough to keep a persons finger and most objects from reaching and engaging the outer end of the conductor. 180; but that passage is large enough to permit a test probe to be inserted therein and to be placed in engagement with that outer end. A nut 182, a lock washer 184 and a second nut 186 are threaded onto the threaded end of the terminal 176, as shown particularly by FIG. 13. The U-shaped contact 174 acts as a contact of the fuseholder 140; and it will receive the ears 118 on the U-shaped terminal 116 on the fuse carrier 20.

The numeral 188 denotes a movable contact which is shown particularly by FIG. 14; and the shank of that contact is passed through an opening 192 in the foot of an L-shaped terminal 190 and then staked to provide two ears thereon. Those ears will prevent accidental separation of that movable contact from that L-shaped terminal. An opening in the leg portion of the terminal 190 accommodates a rivet 193; and that rivet fixedly secures that L-shaped terminal to the fuseholder 140. A helical compression spring 194 surrounds the shank of the movable contact 188; and one end of that spring bears against the foot of the L-shaped terminal 190 while the other end of that spring bears against the head of that movable contact. The movable contact 188 acts as a contact of the fuse-holder 140, and it receives the ear 66 on the terminal 54 of the fuse carrier 20.

A boss 196 is formed at the inner surface of the annular projection 146, asindicated particularly by FIGS. 11 and 14; and a second boss 198 also is formed at that inner surface. The lower end of the boss 196 helps define a notch 200; and the upper end of the boss 198 helps define a notch 202. The notch 200 is dimensioned to accommodate the ear 68 on the terminal 54, and the notch 202 is dimensioned to accommodate the car 66 on that terminal. Once those ears have been telescoped through those notches, the knob 74 can be rotated to rotate the

ears

66 and 68 into underlying relation, respectively, with the

bosses

198 and 196, as shown by FIG. 14. As the ear 66 moves inwardly through the notch 202, it will engage the head of the movable contact 188; and it will move that head rearwardly to the position shown by FIG. 14. p

The numeral 204 denotes an elongated groove at the inner surface of the recess 157 in the fuseholder 140; and that groove is dimensioned to accommodate the elongating guiding surface 24 on the element 21 of the fuse carrier 20. The numeral 206 denotes a second elongated groove at the inner surface of that recess which is dimensioned to accommodate the elongated guiding surface 22 on that element. An abutment 208 is provided at the inner surface of the recess 157, and that abutment is shown particularly by FIGS. and 16; and a second abutment 210 is provided at the inner surface of that recess as shown particularly by FIGS. 11, 15 and 16. As indicated particularly by FIGS. 11 and 16, the

abutments

208 and 210 extend inwardly from the portions of the fuseholder 140 that define the elongated similar to fuse carriers and fuseholders previously marketed by the assignee of this invention. However, the bell-like flange 130 on the fuse terminal 12 8;the stop 106, the shoulder 37, the surface 36,the open area 27, the

abutments

208 and 210, and the interrelationships therebetween are parts of the present invention.

In assembling the electric fuse 126 with the fuse carrier 20, the electrician or maintenance man will dispose that fuse so the axis thereof is parallel to the axis of that fuse carrier, and so the terminal 128 of that fuse overlies the fuse clip 110 while the terminal 132 of that fuse overlies the fuse clip 120. Thereupon, that electrician or maintenance man will force the terminal 128 downwardly into fully seated position within the fuse clip 110 while forcing the terminal 132 downwardly into fully seated position within the'fuse clip 120. The bell-like flange 130 at the free edge of the terminal 128 will move downwardly below the level of the surface 34 on the element 21 of thefusecarrier 20, as shown particularly by FIGS. 2 and 3; and that bell-like flange will be disposed to the left of the vertically-directed portion of the stop 106. The cylindrical casing of the fuse 126 is dimensioned to extend down into the U-shaped slot' whenever that plunger is in its retracted position. It I should also be noted that the U-shaped slot 108 inthe vertically-directed portion of the stop 106 is narrower than the diameter of the bell-like flange 130 on the terminal 128. As a result, that stop will not permit that bell-like flange to pass through that slot; and hence that stop will coact with that bell-like flange to make certain that the plunger 134 will normally permit the pin to be in the circuit-open position shown by FIGS. 1 and 14. This is desirable; because it will keep the electrician or maintenance man from axially shifting the fuse 126 so close to the right-hand end of the fuse carrier 20 as to cause the plunger 134 to engage the cap 102, and thereby force the pin 100 into circuit-closing engagement with the rivet 56. All of this means that the stop 106 and the bell-like flange 130 on the terminal 128 coact together to prevent premature and undesired circuit-closing movement of the pin 100.

Further, it should be noted that the fuse clip is spaced just far enough to the left of the verticallydirected portion of the stop 106 to permit the bellshaped flange to be disposed between that clip and that vertically-directed portion. As a result, the clip 110 can coact with the vertically-directed portion of the stop 106 to prevent axial shifting of the fuse 126 away from the cap 102 on the pin 100. The overall result is that the stop 106 and the clip 110 will coact to make certain that the plunger 134 of the fuse 126 is close enough to the cap 102 to move the pin 100 into engagement with the rivet 56 when that plunger is released from its retracted position, but is far enough away from that cap to avoid premature movement of that pin into engagement with that rivet.

The shoulder 39 on the element 21 helps position the fuse clip 120; and the left-hand edge of that fuse clip is immediately adjacent the surface 36 on that element. That surface is disposed above the level of the lower edge of the bell-like flange 130 on the terminal 128 of the fuse 126, whenever that fuse is fully seated within the fuse clips 110 and 120. This means that if the electrician or maintenance man attempted to effect endfor-end reversal of the electric fuse 1.26, and tried to dispose the terminal 128 within the fuse clip 120 while trying to dispose the terminal 132 within the fuse clip 110, the surface 36 would intercept the lower edge of the bell-like flange 130 on the terminal 128 and prevent full seating of that terminal. Specifically, the surface 36 would force the right-hand end of the electric fuse 126 to remain above the position occupied by the terminal 132 in FIGS. 2 and 3; and the cylindrical housing of that fuse would incline downwardly from upper right to lower left. The resulting cooking of that fuse would immediately indicate to the electrician or maintenance man that he had inadvertently reversed the electric fuse end-for-end; and, thereupon, that electrician or maintenance man would pull that electric fuse from the fuse carrier 20, would reverse that fuse end-for-end, and then would press the terminal 128 downwardly into fully seated position within the fuse clip 110 while pressing the terminal 132 downwardly into fully seated position within the fuse clip 120. It thus will be noted that the surface 36 performs a dual function not only helping define a shoulder which helps fix the position of the fuse clip 120, but also obstructing movement of the terminal 128 downwardly toward fully seated position within the fuse clip 120.

The elongated recess 157 within the fuseholder 140 must be tall enough to accommodate the fuse clips 110 and 120; and it must be wide enough to accommodate the ears 118 on the U-shaped terminal 116. As indicated particularly by FIG. 6, those cars extend outwardly beyond the outer edges of the elongated guiding surfaces 22 and 24 on the element 21. As a result, it is possible to insert the innerend of the fuse carrier 20 into the elongated recess 157 in the fuseholder 140 in the inverted, as well as in the normal, position of that fuse carrier. However, it would be undesirable to permit that fuse carrier to be telescoped fully into position within that recess when that fuse carrier was in its inverted position, because the bottom of the T-shaped plate 94 would not engage the conductor 158 and the projecting end of the stop 106 would not engage the movable contact 156. To keep the fuse carrier 20 from being telescoped fully within the elongated recess 157, when that fuse carrier is in its inverted position, the vertically-directed portion of the stop 106 is made high enough and wide enough to engage and be intercepted by the

abutments

208 and 210 as shown by FIGS. and 16. Those abutments thus coact with the stop 106 to prevent full telescoping of the fuse carrier into the elongated recess 157 within the fuseholder 140 whenever that fuse carrier is in its inverted position. In

doing so, they coact with that stop to make sure that the fuse carrier will not be fully telescoped into that recess unless it is the position which will enable the inner end of that stop to engage the movable contact 156 and which will enable the bottom of the plate 94 to engage the conductor 158.

Whenever the fuse carrier 20 is telescoped fully within the elongated recess 157, and the knob 74 has been rotated to dispose the

ears

66 and 68 behind the

bosses

198 and 196, respectively, current will be able to flow from the center contact 156 via stop 106, clip 110, fuse terminal 128, the fusible element, not shown, of the fuse 126, fuse terminal 132, fuse clip 120, U- shaped terminal 116, U-shaped contact 174, and the rivet 178 to the terminal 176. Although the lower end of the T-shaped plate 94 will be in engagement with the conductor 158, and thus will place the pin in electrical contact with the solder lug 164, the helical compression spring 104 will be holding the head of that pin out of engagement with the rivet 56. Consequently, even though the ear 66 is in engagement with the movable contact 188, and thus is electrically connecting the lamp 88 to the terminal 190, no current will be able to flow through that lamp, because the pin 100 will be out of engagement with the rivet 56. This means that as long as the current flowing through the circuit, to be protected by the electric fuse 126, does not exceed the rated current of that fuse, the lamp 88 will remain deenergized. However, if the current flowing through the circuit causes the fusible element of the fuse 126 to fuse, a helical compression spring, not shown, within that fuse will force the plunger 134 to move from the position shown by FIGS. 2 and 13-15 to the position shown by FIG. 3. As that plunger moves to that position, it will engage the cap 102 and force the pin 100 to move to the right until the head of that pin engages the rivet 56, as shown by FIG. 3. Thereupon, current will flow from solder lug 164 via rivet 162, conductor 158, T-shaped plate 94, pin 100, rivet 56, resistor 84, lamp 88, lamp lead 90, terminal 54, the ear 66 on that terminal, and movable contact 188 to the terminal 190. The resulting flow of current will illuminate the lamp 88, and will thereby clearly indicate that the fuse 126 has opened the power-supplying circuit. At such time, the electrician or maintenance man will grasp the knob 74, will rotate that knob and the terminal 54 until the

ears

66 and 68 are aligned, respectively, with the

notches

202 and 200, and will then withdraw the fuse carrier 20 from the elongated recess 157 within the fuseholder 140. After he has removed the fuse which opened the circuit, and after he has checked the circuit to eliminate the short circuit or undue load, the electri clan or maintenance man will insert a fresh fuse 126 into the fuse clips and on the fuse carrier 20. The surface 36 will coact with the bell-shaped flange on the terminal 128 of the replacement fuse to prevent end-for-end reversal of that fuse. Also, the stop 106 will coact with that bell-like flange to make certain that the desired spacing is provided between the head of the plunger 134 on that replacement fuse and the cap 102 on the pin 100. Moreover, the

abutments

208 and 210 will coact with the vertically-directed portion of the stop 106 to keep the fuse carrier 20 from being inserted within the elongated recess 157 when that fuse carrier is in its inverted position.

The present invention is particularly useful in assur-' ing proper orientation of an indicator-equipped electric fuse within the fuse clips of a fuse carrier. However, the present invention could be used with other devices which are elongated in form, which have ferrule-like terminals at the opposite ends thereof, and which require a predetermined orientation. For example, a diode-containing fuse could be equipped with a ferrulelike terminal that had a bell-like flange thereon; and such a fuse could be assured of proper orientation within the fuse clips 110 and 120 because of the presence of that flange and the surface 36.-Further, if a diode were to be encased within a cylindrical housing which had a ferrule-like terminal with a bell-like flange thereon, that diode could be inserted within the clips 1 l and 120 with the proper orientation.

Whereas the drawing and accompanying description have shown and described a preferred embodiment of the present invention, it should be apparent to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof.

What I claim is:

'1. The combination of a fuseholder and a fuse carrier which can be telescoped into said fuseholder wherein said fuse carrier comprises an elongated element of insulating material, metal fuse-receiving clips fixedly secured to said element, and a stop fixedly secured to said element, and wherein said fuseholder has an elongated recess therein into which said fuse-holder can be telescoped and has contacts which can electrically connect said clips to an electric circuit, said element and said clips of said fuse carrier being dimensioned to telescope into said recess in both the normal and inverted positions of said fuse carrier but said contacts electrically connecting said clips to said electric circuit only when said fuse carrier is telescoped into said recess in its normal position, said stop having a portion thereof projecting laterally outwardly beyond the lateral limits of said clips, and said fuseholder having an abutment therein which is located out of the paths of said clips whether said fuse carrier is telescoped into said recess in its normal or in its inverted position and which is located out of the path of said stop whenever said fuse carrier is telescoped into said recess in its nor-. mal position but which is located in the path of said stop whenever said fuse carrier is telescoped into said recess in its inverted position, whereby said abutment in said fuseholder coacts with said stop on said fuse carrier to prevent telescoping of said fuse, carrier into said recess in its inverted position.

2. The combination of fuseholder and fuse carrier claimed in claim 1 wherein a guiding surface on said fuse carrier interacts with a guiding surface on said fuseholder to guide said fuse carrier as it is telescoped into said recess in its normal position, and wherein said abutment in said fuseholder is immediately adjacent said guiding surface in said fuseholder.

3. The combination of fuseholder and fuse carrier claimed in claim 1 wherein said stop on said fuse carrier is close to that end of said fuse carrier which enters said recess, and wherein said abutment in said fuseholder is close to the outer end of said recess, whereby said stop engages and is held by said abutment shortly after said end of said fuse carrier has been telescoped into said recess.

4. The combination of fuseholder and fuse carrier claimed in claim 1 wherein said clipsare dimensioned to receive and hold an electric fuse which has a normally retracted plunger adjacent one end thereof and which has a protuberance adjacent the other end thereof, wherein a circuit-closing member is mounted on said fuse carrier, wherein said stop is formed and dimensioned to lie in the path of said protuberance on said electric fuse and thereby limit shifting of said electric' fuse toward said circuit-closing member, and wherein said stop is spaced from said circuit-closing member a distance which will, whenever said electric fuse is held by said clips, keep said plunger from engaging said circuit-closing member aslong as said plunger is in its retracted position but which will permit said plunger to move said circuit-closing member into circuit-closing position whenever said plunger is released from its retracted position, whereby said stop performs the dual function of keeping said fuse carrier from being telescoped into said recess in itsinverted position and of keeping said plunger from engaging said circuitclosing member as long'as said plunger remains in its retracted position. Y I 3 5. The combination of a fuseholder and fuse carrier which can be telescoped into saidfuseholder wherein said fuse carrier comprises an elongated element of insulating material, metal fuse-receiving clips fixedly secured to said element, and a stop fixedly secured to said element, and wherein said fuseholder has-an elongated recess therein into which said fuse carrier can be telescoped and has contacts which can electrically con nect said clips to an electric circuit, said element and said clips of said fuse carrier being dimensioned to telescope into said recess in both the normal and inverted positions of said fuse carrier but said contacts electrically connecting said clips to said electric circuit only when said fuse carrier is telescoped into said recess in its normal position, said stop having a portion thereof projecting laterally outwardly beyond the lateral limits of,said clips, and said fuseholder having an abutment therein which is located out of the paths of said clips whether said fuse carrier is telescoped into said recess in its normal or in its inverted position and which is located out of the path of said stop whenever said fuse carrier is telescoped into said recess in its normal position but which is located in the path ofsaid stop whenever said fuse carrier is telescoped into said recess in its inverted position, whereby said abutment in said fuseholder coacts with said stop on said fuse carrier to prevent telescoping of said fuse carrier into said recess in its inverted position, said stop having a portion which is located between said clips and which is directed transversely of said element, and said portion of said stop having an open area therein to accommodate part ofa fuse held bysaid clips.

6. The combination of a fuseholder and fuse carrier which can be telescoped into said fuseholder wherein said fuse carrier comprises an elongated element of insulating material, metal fuse-receiving clips fixedly secured to said element, and a stop fixedly secured to said element, and wherein said fuseholder has an elongated recess therein into which said fuse carrier can be telescoped and has contacts which can electrically connect said clips to an electric circuit, said element and said clips of said fuse carrier being dimensioned to telescope into said recess in both the normal and inverted positions of said fuse carrier but said contacts electrically connecting said clips to said electric circuit only when said fuse carrier is telescoped into said recess in its normal position, said stop having a portion thereof projecting laterally outwardly beyond the lateral limits of said clips, and said fuseholder having an abutment therein which is located out of the paths of said clips whether said fuse carrier is telescoped into said recess in its normal or in its inverted position and which is located out of the path of said stop whenever said fuse carrier is telescoped into said recess in its normal position but which is located in the path of said stop whenever said fuse carrier is telescoped into said recess in its inverted position, whereby said abutment in said fuseholder coacts with said stop on said fuse carrier to prevent telescoping of said fuse carrier into said recess in its inverted position, said stop being adjacent to and being electrically connected to one of said clips, and a portion of said stop projecting outwardly of said element to act as a contact of said fuse carrier.

7. A fuse carrier which is selectively movable into and out of an elongated recess within a fuseholder and which comprises an elongated element of insulating material, a metal fuse-receiving clip fixedly secured to said element, a second metal fuse-receiving clip fixedly secured to said element at a point which is spaced axially of said element from the first said clip, a circuitclosing member movably mounted on said element, said circuit-closing member being disposed adjacent said first said clip but being disposed axially beyond the outer end of said first said clip, said clips being dimensioned to receive and hold an electric fuse which has a normally-retracted plunger adjacent one end thereof and which has a protuberance adjacent the other end thereof, said clips being aligned to hold said plunger in register with said circuit-closing member, and a stop on said element adjacent said second clip, said stop being formed and dimensioned to lie in the path of said protuberance on said electric fuse and thereby limit shifting of said electric fuse axially toward said circuit-closing member, said stop being spaced from said circuit-closing member a distance which will, whenever said electric fuse is held by said clips, keep said plunger from engaging said circuit-closing member as long as said plunger is in its retracted position but which will permit said plunger to move said circuit-closing member into circuit-closing position whenever said plunger is released from its retracted position, said stop being spaced from said second clip a distance sufflcient to accommodate said protuberance, the axial distance between said stop and the confronting edge of said second clip being short enough to keep said plunger from being moved so far axially away from said circuitclosing member that said plunger would be unable to move said circuit-closing member into circuit-closing position when said plunger is released from its retracted position.

8. A fuse carrier as claimed in claim 7 wherein said protuberance is a bell-like flange on a ferrule-like terminal of said electric fuse, and wherein said stop has a surface which is intermediate the confronting edges of said clips and which lies in the path of said bell-like flange.

9. A fuse carrier as claimed in claim 7 wherein said protuberance is a flange on a ferrule-like terminal of said electric fuse, wherein said stop has a surface which is intermediate the confronting edges of said clips and which lies in the path of said flange, and wherein said surface on said stop is spaced inwardly of the confronting edge of said second clip to define a space which can accommodate said flange.

10. A fuse carrier as claimed in claim 7 wherein said stop has a portion thereof which underlies said second clip and which extends axially beyond the outer edge of said second clip, and wherein said stop is electrically connected to said second clip, whereby said portion of said stop serves as a contact of said fuse carrier.

11. The combination of a fuseholder and a fuse carrier, for an electric fuse which has a generally bellshaped annular flange on one of the terminals thereof, that can be telescoped into said fuseholder, wherein said fuse carrier comprises an elongated element of insulating material, a metal clip which is fixedly secured to said element and which is dimensioned to receive and electrically engage said one terminal of said electric fuse, a second metal clip which is fixedly secured to said element and which is dimensioned to receive and electrically engage a second terminal of said electric fuse, said metal clips being spaced apart along the length of said element and having a spacing therebetween comparable to the spacing between said terminals of said electric fuse, said element having a surface thereon adjacent said second clip which will intercept said generally bell-shaped annular flange on said one terminal of said electric fuse if an effort is made to seat said one terminal of said electric fuse within said second clip, said element having an open area adjacent the first said clip to accommodate said generally bell-shaped annular flange on said one terminal of said electric fuse, whereby said element assures a desired orientation of said electric fuse relative to said element and said clips and wherein said fuseholder has an elongated recess therein into which said fuse carrier can be telescoped and has contacts which can electrically connect said clips to an electric circuit, said element and said clips of said fuse carrier and said generally bell-shaped annular flange on said one terminal of said electric fuse being dimensioned to enable said fuse carrier to telescope fully into said recess and thereby permit both of said clips to electrically engage their corresponding contacts in said fuseholder when said one terminal of said electric fuse is fully seated within and held by said first said clip on said fuse carrier and said second terminal of said electric fuse is fully seated within and held by said second clip on said fuse carrier, said generally bell-shaped annular flange on said one terminal of said electric fuse being dimensioned to engage one of said contacts in said fuseholder and thereby keep said fuse carrier from 13. A carrier as claimed in claim 11 wherein said element hasa shoulder immediately adjacent one end of said surface, wherein said shoulder is abutted by, and helps to position, said second clip, and wherein said open area is intermediate said first said clip and av second shoulder on said element.

Claims

1. The combination of a fuseholder and a fuse carrier which can be telescoped into said fuseholder wherein said fuse carrier comprises an elongated element of insulating material, metal fuse-receiving clips fixedly secured to said element, and a stop fixedly secured to said element, and wherein said fuseholder has an elongated recess therein into which said fuse-holder can be telescoped and has contacts which can electrically connect said clips to an electric circuit, said element and said clips of said fuse carrier being dimensioned to telescope into said recess in both the normal and inverted positions of said fuse carrier but said contacts electrically connecting said clips to said electric circuit only when said fuse carrier is telescoped into said recess in its normal position, said stop having a portion thereof projecting laterally outwardly beyond the lateral limits of said clips, and said fuseholder having an abutment therein which is located out of the paths of said clips whether said fuse carrier is telescoped into said recess in its normal or in its inverted position and which is located out of the path of said stop whenever said fuse carrier is telescoped into said recess in its normal position but which is located in the path of said stop whenever said fuse carrier is telescoped into said recess in its inverted position, whereby said abutment in said fuseholder coacts with said stop on said fuse carrier to prevent telescoping of said fuse carrier into said recess in its inverted position.

4. The combination of fuseholder and fuse carrier claimed in claim 1 wherein said clips are dimensioned to receive and hold an electric fuse which has a normally retracted plunger adjacent one end thereof and which has a protuberance adjacent the other end thereof, wherein a circuit-closing member is mounted on said fuse carrier, wherein said stop is formed and dimensioned to lie in the path of said protuberance on said electric fuse and thereby limit shifting of said electric fuse toward said circuit-closing member, and wherein said stop is spaced from said circuit-closing member a distance which will, whenever said electric fuse is held by said clips, keep said plunger from engaging said circuit-closing member as long as said plunger is in its retracted position but which will permit said plunger to move said circuit-closing member into circuit-closing position whenever said plunger is released from its retracted position, whereby said stop performs the dual function of keeping said fuse carrier from being telescoped into said recess in its inverted position and of kEeping said plunger from engaging said circuit-closing member as long as said plunger remains in its retracted position.

5. The combination of a fuseholder and fuse carrier which can be telescoped into said fuseholder wherein said fuse carrier comprises an elongated element of insulating material, metal fuse-receiving clips fixedly secured to said element, and a stop fixedly secured to said element, and wherein said fuseholder has an elongated recess therein into which said fuse carrier can be telescoped and has contacts which can electrically connect said clips to an electric circuit, said element and said clips of said fuse carrier being dimensioned to telescope into said recess in both the normal and inverted positions of said fuse carrier but said contacts electrically connecting said clips to said electric circuit only when said fuse carrier is telescoped into said recess in its normal position, said stop having a portion thereof projecting laterally outwardly beyond the lateral limits of said clips, and said fuseholder having an abutment therein which is located out of the paths of said clips whether said fuse carrier is telescoped into said recess in its normal or in its inverted position and which is located out of the path of said stop whenever said fuse carrier is telescoped into said recess in its normal position but which is located in the path of said stop whenever said fuse carrier is telescoped into said recess in its inverted position, whereby said abutment in said fuseholder coacts with said stop on said fuse carrier to prevent telescoping of said fuse carrier into said recess in its inverted position, said stop having a portion which is located between said clips and which is directed transversely of said element, and said portion of said stop having an open area therein to accommodate part of a fuse held by said clips.

7. A fuse carrier which is selectively movable into and out of an elongated recess within a fuseholder and which comprises an elongated element of insulating material, a metal fuse-receiving clip fixedly secured to said element, a second metal fuse-receiving clip fixedly secured to said element at a point which is spaced axially of said element from the first said clip, a circuit-closing member movably mounted on said element, said circuit-closing member being dispOsed adjacent said first said clip but being disposed axially beyond the outer end of said first said clip, said clips being dimensioned to receive and hold an electric fuse which has a normally-retracted plunger adjacent one end thereof and which has a protuberance adjacent the other end thereof, said clips being aligned to hold said plunger in register with said circuit-closing member, and a stop on said element adjacent said second clip, said stop being formed and dimensioned to lie in the path of said protuberance on said electric fuse and thereby limit shifting of said electric fuse axially toward said circuit-closing member, said stop being spaced from said circuit-closing member a distance which will, whenever said electric fuse is held by said clips, keep said plunger from engaging said circuit-closing member as long as said plunger is in its retracted position but which will permit said plunger to move said circuit-closing member into circuit-closing position whenever said plunger is released from its retracted position, said stop being spaced from said second clip a distance sufficient to accommodate said protuberance, the axial distance between said stop and the confronting edge of said second clip being short enough to keep said plunger from being moved so far axially away from said circuit-closing member that said plunger would be unable to move said circuit-closing member into circuit-closing position when said plunger is released from its retracted position.

11. The combination of a fuseholder and a fuse carrier, for an electric fuse which has a generally bell-shaped annular flange on one of the terminals thereof, that can be telescoped into said fuseholder, wherein said fuse carrier comprises an elongated element of insulating material, a metal clip which is fixedly secured to said element and which is dimensioned to receive and electrically engage said one terminal of said electric fuse, a second metal clip which is fixedly secured to said element and which is dimensioned to receive and electrically engage a second terminal of said electric fuse, said metal clips being spaced apart along the length of said element and having a spacing therebetween comparable to the spacing between said terminals of said electric fuse, said element having a surface thereon adjacent said second clip which will intercept said generally bell-shaped annular flange on said one terminal of said electric fuse if an effort is made to seat said one terminal of said electric fuse within said second clip, said element having an open area adjacent the first said clip to accommodate said generally bell-shaped annular flange on said one terminal of said electric fuse, whereby said element assures a desired orientation of said electric fuse relative to said element and said clips and wherein said fuseholder has an elongated recess therein into which said fuse carrier can be telescoped and has contacts which can electrically connect said clips to an electric circuit, said elemenT and said clips of said fuse carrier and said generally bell-shaped annular flange on said one terminal of said electric fuse being dimensioned to enable said fuse carrier to telescope fully into said recess and thereby permit both of said clips to electrically engage their corresponding contacts in said fuseholder when said one terminal of said electric fuse is fully seated within and held by said first said clip on said fuse carrier and said second terminal of said electric fuse is fully seated within and held by said second clip on said fuse carrier, said generally bell-shaped annular flange on said one terminal of said electric fuse being dimensioned to engage one of said contacts in said fuseholder and thereby keep said fuse carrier from being telescoped fully into said recess and thus keep at least one of said clips from electrically engaging its corresponding contact in said fuseholder when said second terminal of said electric fuse is fully seated within and held by said first said clip on said fuse carrier but said one terminal of said electric fuse is kept from being fully seated within and held by said second clip on said fuse carrier because of the engagement between said generally bell-shaped annular flange on said one terminal of said electric fuse and said surface on said element.

12. A carrier as claimed in claim 11 wherein said surface on said element is located between the confronting edges of said clips, wherein said open area on said element is intermediate said confronting edges of said clips, wherein said surface is an exposed surface of an increased-thickness section of said element, and wherein said open area is adjacent a reduced-thickness section of said element.

13. A carrier as claimed in claim 11 wherein said element has a shoulder immediately adjacent one end of said surface, wherein said shoulder is abutted by, and helps to position, said second clip, and wherein said open area is intermediate said first said clip and a second shoulder on said element.