US1460914A - Combined electric switch and fuse - Google Patents

Description

July 3, 1923. 1,460,914

J. G. LUNDGREN COMBINED ELECTRIC SWITCH AND FUSE Filed Jan. 26, 1921 2 Sheets-Sheet 1 (fa/M5 6. Zufldyrm,

: 'JuIy' '3, 1923.

- J. G. LUNDGREN COMBINED ELECTRIC SWITCH AND FUSE 1921 2 Sheets-Sheet 2 Filed Jan. 26

:u a I Patented July 3, 1923..

UNITED STATES JONAS G. LUNDGEEN, OF CLEAR LAKE, 101 3 11.

COMBINED ELEG'IRIC FEWIZ'GH JZ-NND FUSE.

Application filed January 26,

1 0 all whom it may concern:

Be it known that 1, Jones Gosriir Lonn- GREN, citizen of the United States, residing at Clear Lake, in the county of Gerro Gordo and State of Iowa, have invented new and useful Improvements in Combined Electric Switches and Fuses, of which the following is a specification.

My invention relates to a combined fuse and switch construction.

In many electrical installations the fuse exposed to view with the result that when thefusible element has burned out there is a temptation, which is frequently yield d to especially if there is no supply of the proper fusible elements on hand, to put a copper wire or some like form of conductor in the place of the fuse. This procedure, as is well known to those skilled in the art to which this invention appertains, frequently leads to serious trouble which would not occur if the fusible element had been in place and capable of performing its function. Furthermore, the service switch .irequent ly placed in exposed places where children or unauthorized persons may come in contact with the terminals with resulting serious consequences.

This invention aims to avoid these and other difiiculties and also to provide a coinpact arrangement whereby the fuse and switch are combined in a unitary structure wherein the fuse is not exposed to view and wherein the terminals of the switch are also concealed.

This invention also aims to provide a fuse construction which may be readily assembled and disassembled for inspecting or replacing the fusible element.

Another object of my invention is to provide a combined fuse and switch-block so arranged that the conductors may be firmly and readily connected thereto.

Other objects of the invention which consist in novel features of construction and rangements of parts whereby a compact and economical structure is obtained, will be-- come apparent on reference to the following specification which describes the invention in connection with the accompanying drawings.

In the drawings Figure 1 is a plan View of one form of my invention showing a plurality of terminals disposed on a switch-block.

Figure 2 is a central sectional view Figure is a perspective view showing the parts comprisin the detachable cap and screw of the switch mechanism in separated position.

Figure (3 is a plan View of another form of my invention showing the switch elements pivotally connected.

Figure 7 is a central longitudinal section through one of the switch elements.

Figure 8 is an end view of the switch in closed position showing one of the switch elements in section on the line 88 of Fi ure 7. c

Figure 9 is a vertical section through one at the terminal connections to the switchbloclr. the section being taken on the line 9-4) of Figure 7.

Heifer-ring to the form of the invention ill trated in Figures ii to 5, the numeral 10 desig toe the switch-block which is preferably l' substantially rectangular shape and formed of some insulatingmaterial such as porcelain or balrelite. This block is torn x, with transverse grooves which are ad: .icd to receive the insulated conductors 12. These grooves are intersected near opposite sides of the block by slots 13, in which are located the switch blades consisting of flat elongated base portions is: disposed in the bottom of the slots and secured to the block by means of suitable screws or other fastening devices (not shown). Upstandinefrom the bases are the blades 15 which are adapted to cooperate with the spring lingers of the detachable switch and fuse mechanism. Each base portion lei is extended into a groove 11 and is provided with apertures and screw threads which apertures are spaced apart suflicient disbare wire to pass thcrethrough, so that at this point the insulation is cut away :lirom the wire, and a metallic plate 16 of proper dimension having suitably quaced apertures is used to clamp the wire position and make good electrical "herewith and for this purpose the are passed through the apertures of the plate 16 and engage the threaded apertures of the plate 141-. Recesses 20 are formed near each corner of the block and in axial alignment with the slots 13. Means are provided in each of the recesses for electrically connecting the terminals of an electrical conductor to a terminal of the switch block and this means comprises a metallic plate 21 located in the base of each recess and properly secured to the block 10 and another metallic plate between which plates the uninsulated portion 23 of the conductor is inserted, the irsula ion shown at 2 1 being received through a vertical slot of proper dimension formed in the switch block.

The base-plate 21 is provided with apertures and screw threads and the upper plate 22 has suitable apertures for receiving the screws 25 whereby the two plates may firmly bind the uninsulated portion of the conductor between them. 11. blade 26 is attached to or formed integral with the upper plate 22 and is adapted to cooperate with the spring lingers 33 of a detachable combined switch and fuse d "cc as will hereinafter appear. its show. in, Figure 1, there are four switch blades 26 arrant d near the corners of the rectangular SWlLCllblock and two switch blades 15 which le ter are connected with the transversely extending conductors 12. p

The combined fuse and switch devices are provided so that pairs of these blades 15 and 26 may be variously connected in ac cordanee with conditions. These combined switch and fuse mechanisi'ns are designated as a whole by the numeral 80 and each consists of a cylindrical, hollow casing 310i insulating material in each end of "which is inserted or embedded a threaded metallic bushing 32 and this bushing is provided with spring fingers 83 adapted to engage and make contact with the switch blades l5 and 26 in the usual manner. may be attached to the casing in any suit able manner. The outer end of each pin or rivet projects into an opening formed in the casing and this opening is subsequently filled by a plug 29 of wood, wax, putty or the like so that the outer surface of the easing is continuous and of even contour, as shown in Figure 2.

The fuse is of novel construction in order that the same may be readily disassenv bled and assembled, and for this purpose a cylindrical fuse body 3-1 of insulating material and of such dimension as to be capable of fitting within the hollow casing 31, is provided. The fuse body is formed with central bore 36 and with rece sed ends 37 in The bushing joint adaptediio connect the cap to the fuse body. It w l be noted that in Figure 4: the

upper surf e of the groove 16 is shown as 12 'ovided with a slight taper indicated at 4?! so that the cap may be pressed into firm electrical contact with the corresponding end 4h) of the fuse 11. However, it will be noted that a strai ht surface may also be used in connection with the groove 46 of the T. yonet joint since the screw-plugs 18, hereinafter described, will force the caps 41 mly into contact with the flat portions -10 the fusible element. The fuse body shown 1' l is adapted to be inserted within block or casing 31 and the metallic -?eof extend within the threaded portions of the bushings 32. In order to 1' "we certain of good electrical connections between the bushings 32 and the fuse, a nut r screw-plug 4-8 of metallic material, such bras s provided with threads for enlugthe threads of each bushing 32 and erting these screw-plugs in the opposite ends of the casing 31, the fuse is firmly held therebetween. Each screw 18 is also provieed with a central threaded aperture l9 and with a kerf 50 adapted to engage a row-driver whereby the plug 49 may be easily detached. For the purpose of concealing the conducting parts of the apparatus and pre'venti g accidental contact therew ith, a cap 51 of non-conducting material is formed with a slotted boss 52, the slot of which is adapted to engage the head of a T-shaped element 53 having a threaded stem 51 adapted to engage the threads 4-9 of the screwplug. The T-shaped element is provided with an aperture 37 which is adapted to align with an aperture 56 passing transversely through the hub 52, whereby a removable pin or wire may be inserted for retaining the cap 51 and the T-shaped element in assembled relation. By removing the pin from the apertures and 56 and placing the stem in the central aperture 54 of the cap 51. the T-sl -aped element will be positioned for engaging the kerf 50, and thereby functioning as a screw-driver with relation to the plug 48, or the T-shaped element may be used as a screw-driver independently of the cap 51.

In assembling the detachable switch and fuse mechanism, the assembled fuse is inted within the casing 31, screw plugs 48 are applied and the caps 51 are secured to these plugs, whereby the device presents aneat appearance and exposes only the insulating material of the casing 31 and caps 51 to view, with the exception of the switch blades 33, which extend downwardly through slots in the casing. As said before, these combined switch and fuse devices connect the switch blades 15 and 26, and since the latter are located in slots in the switch block 10 and the block is provided with cylindrical depressions 57 of substantially the same or slightly larger diameter than the casings 31 it will be apparent that when the switch devices are applied in closed position that the conducting terminals are protected from accidental contact therewith by i-L'PGl'SOD not acquainted with the construct-ion of the switch mechanism and that anyone accidentally coming into contact therewith is in little danger of being subjected to an electrical shock.

In case the fuse is burnt out, or is de c tive, or in order to inspect; remove the cap 51, the plug 48 and shake out the fuse lody 34:, the caps l1 can then be readily de y and the disks 38 removed. l nder these conditions the interior of the switch block is exposed to view, as well as the fuse element and if it is desired to put another fuse element in place it is only necessary to i rt the same through the apertures cf the disks 38, after removing the spent fuse as above described. The switch block 10 is provided with openings 58 for receiving suitable means for fastening the switch mechanism to a wall or switch board slab.

Another form of my invention illustrated in Figures 6 to 9, differs from the form just described chiefly in having the switch members pivotally mounted instead of completely removable and this form is primarily intended for a main or service switcl. The switch mechanism is mounted upon a block 60 having two forward recesses 61 and two rear recesses 62 formed therein. In each of the rear recesses 62 a base plate 63 is placed, see Figure 9, on which is mounted a bent plate 65 having an upstanding blade portion 66 to which the hollow cylindrical casing 67 of the movable switch member is pivotally connected in a manner hereinafter described. The rear end of each casing 67 is closed by a metallic plug 68 having spaced fingers 69 extending therefrom for embracing the upstanding blade 66 of the bent plate 65. A pin 70 is passed through aligning apertures formed in the blade 66 and vlingers 69, this pin being retained in position by suitable retainers such as washers 71 and the riveted ends of the pin 70 which prevent lateral movement of the washers. It vill be understood that other retaining means such as cotter pins or screws and nuts or the like may be used instead of the means herein employed. In order to allow pivotal movement of the casings 67 about the blades 66 said casings are provided with vertical slots 72 which provide clearance for the blades 66 during pivotal movements of the casings.

In the forward recesses 61 a base plate 75 is inserted and upon this plate is placed an elongated plate 76. The plate 75 is provided with a curved portion 77 which is produced upwardly into the vertical blade 78. The plates 75 and 76 are secured to the switch blocl; 60 by suitable fastening devices (not shown) and the plate '75 is provided with apertures adapted to align with suitable apertures formed in a plate 80 which engages over the uninsulated portion of the wire 81 for tightly clamping the wire into electrical contact with the plate 76 and for this purpose screws 82 are inserted through the aligning apertures and the plate is pressed downwardly until the wire is tightly clamped between the plate 80 and the plate 76.. The wires 83 leading into the rear recesses are secured in place in similar main ner by means of the upper contact plate which is provided wit-h apertures through which screws 85 are inserted for the purpose of e: L lging threaded apertures in the plate 63, suitable openings being made in the block 60 to allow the screws to be tightei'ied.

Each hollow cylindrical casing 67 is closed at one end by the metallic plug 68. and a fuse 66, similar in construction to the fuse described in connection with the first form of my invention inser ed within each ing until the metallic cap 87 of one end of the fuse is received within and contacts with the shell of the plug 68. The cap 87 at the other end of the fuse body is received within a threaded bushing 32 having depeiuling spaced lingers 33 for engaging the blade 78 of the forward tern'iii'ials of the switch mechanism. It screw plug 48 screws into the bushing s2 and contacts with the corresponding metallic cap 87. A cap 51. of insulating material is provided with a thread ed stem 54/ adapted to engage a central threaded aperture in the screw plug 48'. The primed numerals represent parts corresponding in construction and function to the parts designated by the corresponding cardinal numerals in the description of Figures 1 to 5. i

The two cylindrical casings 67 are connected together at the forward end by a bridge piece 90 having inwardly projecting ribs 91 secured to the casings. The bridge piece 90 is provided with a circular opening 92 whereby the movable switch members including the casings 67 may be readily manipulated to open or closed position.

hen the switch is in closed position current coming through conductors 81 is transmitted by means of spring finger 33 to threaded bushings 32', from thence to tor S3.

screw plug l8, cap 87 through the fusible element 39, which is substantially the same in each form of the invention herein described, to the rear cap 87, through shell 68, lingers 69, to blade 66 and then to conduc- It is evident that the blowing of the fuse will break this line of conductors and the fuse may be replaced by swinging the casings to open position, taking out the removable parts 51, 48, 87 and the fuse as described in connection with the correspond ing parts of the iii-st form of the invention, inserting the new fuse and assembling the parts in reverse order.

'il he cylindrical openings at the rear of the casings surrounding the spring lingers 69 are closed by means of plugs 88 of insulating material which conform exteriorly to the contour of the casings and except for the continuation of the slots 72 completely conceal the switch blades 66 and spring fingers 69.

The block is also formed with curved longitudinal depressions 89 adapted to receive the lower portions of the casings when the latter are closed and thus conceal the conducting portions of the switch mechanism in a housing of insulating material It will be understood that the particular constructions described and shown have been chosen for illustrative purposes merely and that the invention as defined by the claims hereunto appended, may be otherwise embodied and applied without departing from the spirit and scope thereof.

Having described my invention what 1 claim and desire to secure by Letters Patent, is

1. In an electrical switch, the combination of a switch block having spaced terminals, a casing carrying contacts adapted to make electrical connections with said terminals, a fuse in said casing connecting said contacts, said block having recesses in which said terminals are located and grooves therein in which portions of said casings are adapted to lit, and detachable means for closing an end of said casing whereby when the switch is closed all oi the conducting parts thcreoi are concealed from view.

2. An electrical switch having in combination a movable member consisting oi a h0llow casing, spaced contacts in said casings and iuse ccmpris lig a hollow body, metallic caps detachably connected to said body, a luse clement electrically connecting r: c; and Lt removable plug engaging one of id contacts i'or 'Lorcing sail contacts. caps and fuse element into firm eleccontact.

5. in an electric switch the combination oi a lixcd block of insulating material having recesses form-ed therein, terminals located in said a casing of insulating material hinting c 'acts projecting therefrom adapted [O engage said terminals, a time within the casing electrically connectsaid contacts, said block having grooves in alignment with said rcrece \ing said casing when the latn operative position, whereby the coerminals and contacts are completely said block and casing.

l. in clcctr i switch including a member collelSlI-llllf oi a hollow casing of insulatiip' material having spaced contacts, a fuse within the casi z a removable metallic plug engaging one oi said contacts lf'or making lirm electrical connections between said con tacts and fuse, a cap of i'ioincoinlucting material adapted to act as insulator for said plug, and a disassembling tool detachably connecting said cap and plug.

in testimony whereof l have hereunto set my hand in presence of two subscribing witnesses.

JONAS G. LUNDGREN. Witnesses Gnonen KNULsoN, FRED OPEL.

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