US2669624A - Safety switch and fuse construction - Google Patents

Description

Feb. 16, 1954 J. 5. FERGUSON 2,669,624

SAFETY SWITCH AND FUSE CONSTRUCTION Filed July 24, 1952 2 Sheets-Sheet 1 INVENTOR JOHN S- FERGUSON BY ATTORNEY Feb. 16, 1954 J. s. FERGUSON SAFETY SWITCH AND FUSE CONSTRUCTION Filed July 24, 1952 2 Sheets-Sheet 2 INVENTOR JOHN S. FERGUSON YWQ QW ATTORNEY Patented Feb. 16, 1954 SAFETY SWITCH AND FUSE CONSTRUCTION John S. Ferguson, Glenview,

Ill., assignor to Electric Machinery Manufacturing Company, Minneapolis, Minn.

Application July 24, 1952, Serial No. 300,736

15 Claims.

The herein disclosed invention relates to safety switch and fuse construction and has for an object to provide a construction in which the fuse is disposed within an enclosure having an access opening closed by a door and in which the fuse may be disconnected from the circuit with which it is used upon opening the door.

Another object of the invention resides in providing a fuse carrier mounted within the enclosure and carrying a fuse and in providing the switch with a fuse contact connected to the fuse and movable with the carrier having a terminal contact connected to a terminal of the circuit with which the fuse is used and fixed relative to the enclosure, said carrier being pivoted to a part of said enclosure and having an area sufficient to cause said carrier to close the access opening when the door and switch are in open position and being adapted to bring the fuse contact of the switch into engagement with the terminal contact when the door is in closed position.

A still further object of the invention resides in providing a construction whereby the fuse carrier is moved by movement of the door and in which the door may be moved independently of the fuse carrier to permit closing the door while the fuse carrier is in either position.

Another object of the invention resides in providing a grounding device operable to ground the fuse contact of the carrier when the carrier is moved into position to close the access openmg.

An object oi the invention resides in providing locking means for locking the carrier in open position of the switch when the door is fully open.

Another object of the invention resides in providing a link pivoted to the door and having a bayonet slot therein formed with a longitudinal portion and an offset portion and in providing a part movable with the carrier with a pintle movable in said slot.

Another object of the invention resides in providing a link pivoted to a part fixed relative to the carrier and having a latch lug adapted to cooperate with a shoulder formed on a track along which said lug rides for the purpose of locking the carrier in open position. 4

An object of the invention resides in providing an pivoted to the door and having a longitudinally extending slot in which a pintle carried by the link slide, whereby the carrier be moved to open position and along which the pintle may slide upon closing of the door.

An object of the invention resides in providing an arm pivoted to a part carried by said carrier and carrying said pintle, and in providing stop means between said arm and part for limiting the swinging movement of said arm.

A still further object of the invention resides in forming on said arm a latch lug and in providing a guide carried by the enclosure along which said lug travels and in further forming said guide with a notch providing a shoulder against which said lug may abut to restrain movement of said closure.

Other objects of the invention reside in the novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/0r described.

In the drawings:

i is a side elevational view of a safety switch and fuse construction illustrating an embodiment of the invention with the door closed.

Fig. 2 is a plan sectional view of the structure shown in Fig. l and taken on line 22 of Fig. 1.

Fig. 3 is an elevational sectional view looking from the opposite side and taken on line 3-3 of Fig. 4 is a view similar to Fig. 3 showing the door in open position.

In the drawings a safety switch and fuse construction has been shown which includes a framework forming part of the control apparatus of an electric power system with which the invention is to be used. This construction embodies an enclosure forming part of the control apparatus and including a panel forming a part of the switchboard of the control apparatus. Within this enclosure is mounted a switch and a fuse carrier pivoted to the enclosure. This carrierhas movable switch contacts cooperating with fixed switch contacts carried by the enclosure and connected to suitable terminals of the electric line being fused. The carrier supports fuse clips connected to the movable contacts which serve as a fuse holder for supporting fuses. A door is hingedly connected to the enclosure and has pivotally connected to it a link having a slot therein and receiving a pintle attached to an arm pivoted to a part fixed relative to the carrier. When the pin reaches the outer end of said slot the opening of the door procures swinging of the carrier and disengagement of the movable switch contact from the switch contacts, thus deenergizing the fuse circuits and removing voltage from the fuses. The slot in the pivoted link is of the type known as a bayonet slot and has a longitudinal portion along which the pintle may slide permitting the door to be closed while the carrier is in switch-opening position. The said slot further has an offset portion in which the pintle may be disposed and by means of which the carrier may be moved into switch-closing position. The arm on which the pintle is mounted has formed on it a latch lug which rides along a guide having a notch providing a shoulder against which the latch lug may abut when the carrier is in switch-opening position and which serves to maintain the carrier in such position while the fuses are being examined or replaced. The carrier is constructed of a plate of insulating material which has an area suflicient to substantially close the opening through the closure and obstruct access to the live parts of the electric power system. A shorting device carried by the enclosure engages the fuse clips and grounds the same when the fuse carrier is in switch opening position.

The invention is used as part of a control apparatus .for controlling and indicating the conditions of a power system or any other system in which electrical circuits are to be fused. A.

portion of such apparatus has been shown in the drawings and consists of a main framework H forming part of a switchboard indicated in its entirety by the reference numeral Hi. This framework H consists of stiles 92 which ar arranged at spaced intervals and which are preferably constructed of sheet metal formed in the desired shape. The said stiles have faces I3 constructed with offsets M from which issue flanges l5 disposed inwardly of the said faces. The said stiles have legs l6 extending inwardly from the faces i3 and from which flanges i7 issue which are parallel to the faces i3. These stiles of the switchboard are connected together by means of headers l8 similarly constructed and which are formed in the same manner. In addition, rails 19 are provided which are also connected to said stiles. These rails are also constructed of sheet metal and are bent to form faces 22 with legs 23 and 24 extending inwardly therefrom and from which flanges 25 and 26 issue. The flanges 25 lie in continuation of the flanges l5 of the stiles i2 and the flanges I l of the said stiles lie in the plane of the corresponding flanges of the header [8 and form a rabbet 25 extending about the access opening 2!. These stiles, headers and rails provide sections in the switchboard having access openings 2! and through which the parts disposed within the same are accessible. Attached to the flanges I! are angle frame members 21 which are disposed rearwardly of the rails i9 and other frame members 28 which are connected into and which extend rearwardly from the frame members 2'1. This construction forming no particular part of the invention, has not been shown in its entirety, and it is to be understood that any suitable construction such as now employed for the purpose may be used for supporting the invention and for forming the enclosure thereof.

The access opening 2! in the main framework H is closed by means of a door 29, best shown in detail in Fig. 1, which is received in the rabbet 20. This door is constructed from sheet metal and has a panel 3! with walls 32 bent inwardly therefrom. From these walls issue flanges 33 which lie in a common plane and which are adapted to overlie the flanges 25 of th rail [9 and the flanges iii of the stiles i2 and the header I8. The door 29 is hingedly supported by means of hinges 3 which are secured to leg 23 of rail l9 and to the lowermost of th walls 32 of said door. The door 29 is adapted to swing from closing position, as shown in Fig. 3, to a fully open position, as shown in Fig. 4, and may be manipulated by means of a handle 35 secured to the panel 3 l. A suitable lock, not shown in the drawings, may also be incorporated if desired.

The switch and fuse construction, forming the dominant portion of the invention, is mounted on a switch and fuse framework 35. This'framework consists of a lower frame 3! and an upper frame 38 connected together by means of uprights 39. The lower frame 31 consists of a front angle frame member ii, a rear angle frame member 42, and side angle frame members 43. All of these frame members are welded together and to the uprights 39. The upper frame 38 is similarly constructed with front angle frame members 45, a rear angle frame member 45, and side angle frame members 45. All of these frame members are welded to the upper ends of the uprights 39. The framework 36 is supported through the lower frame 3'! which rests on the angle frame member 2'5 of the main framework H and which is attached thereto by means of bolts 31. The framework 35 is further supported on other supports not shown in the drawings but forming part of the main framework i i.

The invention utilizes a fuse carrier 48 which is constructed from a slab of insulating material and which is of an area commensurate with the area of the access opening 2|. This carrier has a tached to it at its lower end one leaf 49 of a hinge 5! which hinge extends throughout the length of said carrier. Bolts 52 extending through the said carrier and hinge leaf attach the hinge to the carrier. In a similar manner the other hinge leaf 53 of said hinge is secured to one of the flanges 54 of an angle frame momber 55 by means of bolts 55. Frame member 55 is mounted on and attached to the lower frame 31 by welding or otherwise. By means of this construction the carrier 48 may move from switch-closing position as illustrated in Figs. 1 and 3 to switch-opening position as shown in Fig. 4.

The particular switch and fuse construction illustrated in the drawings has been designed for a three-wire power line and three switches 12, 13 and M together with the corresponding fuse holders 15, 75 and 1'! have been shown. These switches and fuses are similar in construction so that only the switch 12 andfuse holder 15 will be described in detail.

The fuse holder 75 is supported on two insu lators 51 and 58 which have mounting plates 6! and 62 at the ends of the same. These insulators are attached to the carrier 48 by means of cap screws 59 extending through said carrier and screwed into the mounting plates 51. overlying the mounting plate 62 of insulator 51 is a bar 53 of conducting material. overlying this bar is a fuse clip 64 best shown in Fig. 2. Screws 65 extend through said clip and said bar and are screwed into the mounting plate 62 and thus attach said bar and clip to the insulator. The bar 63 is formed with a bend 66 to provide a leg 6'! issuing angularly therefrom. This leg passes through a hole 58 in the carrier $8 and the end of the same forms a switch blade designated by the reference character 59. A sleeve 1! of insulating material encircles the leg 5'! and further insulates said leg and the blade 53 from the carrier and adjoining objects. Attached to the insulator 58 is another fuse clip 18 which together with the fuse clip 64 supports a cartridge fuse i9 in the customary manner. The insulator 58, similar to the insulator 5], has attached to it a bar II which is bent and formed with a switch blade which are constructed of insulating material and which extend outwardly from the carrier 48. These barriers are attached to the said carrier by means of clip angles I35. The corners of the said barriers are cut away as indicated at I38 to cause the barriers to clear the framework 36 and to confine movement of said barriers to the space within said framework. These barriers are located one between each fuse and one at each end of the carrier.

The switch 12 is supported on two angle frame members 83 and 84 connected together by means of outwardly inclined angle frame members 85 All of these frame members are welded to the frame 81 and to the uprights 39. Attached to the angleframe members 83 and 84 are insulators 88 and 81 which are secured in the same manner as. the insulators 5! and 58. The manner of attachment is best shown in Fig. 1 in conjunction with the insulators for the switch 14. The insulators 88 and 8! have mounting plates 88 at the outer ends of the same similar to the mounting plates 62 and 8| and from which issue studs 89. Mounted on the studs are switch jaws 9| which are adapted to receive the blades 69 and 82. These jaws are held in place upon the studs 89 by means of nuts 92 and lock nuts 93. It will readily be comprehended that when the carrier '48 is moved from the position shown in Fig. 4 to that shown in Fig. 3 that the blades 69 and 92 are brought into engagement with the jaws 9] and the fuse I9 connected in the circuit, and that when the carrier is moved to the position shown in Fig. 4 the blades are disconnected from the switch jaws and the fuse is isolated from the circult.

.F'or moving the carrier 48 two links 94 and 95 are employed. These links are pivoted to lugs 96 which are secured to the welding or in any other link 94 has a slot 9! suitable manner. The in it which receives a pin 98 attached to an angle bracket 99 which is secured to the'carrier' 48 by means of bolts I III. The pin 98 can slide in the slot 9! so that the door 29 can be closed whether the carrier 48 is in similarly constructed and is best shown in Fig. 4. This link has a longitudinally extending slot I92 which is bayonet in form and is provided with a and an offset portion A pin I84 extending through an arm I05-is and may ride along the an adjusting screw II2. This screw may engage a lug I I3 formed on the bracket I91 whereby the swinging of the arm I05 in an upward direction is restrained. The link 95 and the link 94 operate in unison to disengage the switch from the jaws 9I switches when the tlon shown in Fig.

and to permit of opening the door 29 is moved to the posi- 4. It will be noted that both panel 3| of door 29 by 1 switch; opening or switch-closing position. The link 95 is- H9 or enter the offset por This arm is pivoted by means of a the arm I95 therebeblades 59 and 82.

iii)

of the links 94 and 95 are constructed with "off sets II4 which cause the said links to engage the flanges 33 of the door 29 and to limit swinging movement of the door relative to said links.

Extending across the uprights 39 of the frame--v work 38 adjacent the link 94 is an angle cross frame member 5. This frame member is welded to said uprights and has attached to itby means of bolts H8 an arcuate guide III. This guide is constructed with a notch I I8 best shown in Fig. 3 and which forms a shoulder II9 facing outwardly of the guide. The guide II! has an arcuate surface I2I which is concentric with the axis of the hinge 5| for the carrier 48. The arm I 85 has attached to the underside thereof a latch lug I22 which is adapted to ride on the surface I2I as the carrier 48 swings from one position to the other. When the latch lug I22 reaches the notch H8, it drops into said notch and the shoulder H9 restrains movement of the carrier into switch-closing position.

Extending through the plate I88 is a bolt I23 which is provided with a nut I24 and a lock nut I25. A compression coil spring I28 encircles this bolt and is seated at one end against the plate I88 and at its other end against the head I21 of said bolt. This head is adapted to engage a lug I 28 cast on the guide Ill and serves as a bumper for absorbing the shock when the blades 69 and 82 are disengaged from the jaws 9| and the carrier is brought into switch opening position.

For checking the movement of the door 29, a door check I29 is employed which is pivoted to a block I3I secured to one of the angle frame members 85. This door check has a piston rod I32 which is pivoted to a bracket I33 fastened on the door 29. In this manner, slamming the door during either opening or closing operations does not injure the door or the structures controlled thereby.

To further safeguard the operator in the removal of fuses from the fuse holders, a grounding device I3! is used for each fuse holder. This grounding device consists of a contact blade I38 having a curved leading edge I39. The said blade is supported on a flexible hanger I4I which is secured to a clip I42. Clip I42 is mounted on an angle cross frame member I43 which is attached to the upper frame 38 of the framework 36. When the carrier 48 is moved into switch-open-, ing position, the clip 84 engages the contact blade I38 and the same are grounded through the framework 38 and the main framework II.

The method of operation of the invention is as follows:

Assume that the door 29 is closed as shown in Figs. 1 and 3 and-that the switches ?2, I3 and 74 are in closed position. Pins 68 and IE4 are at the ends of the slots 91 and W2 of links 94 and 95. Outward movement of the door 29, hence, causes both of these links to disengage the blades 89 and 82 from theswitch jaws SI and to swing the door to the position shown in Fig. 4. As the carrier 48 is moved forwardly, the lug I22 rides cnthe surface iZI of guide .I I1 until it drops into the notch H8. As the said carrier reaches this position, the head i2? of bolt I23 engages lug I 28 and the movement of the said carrier is retarded. When the lug I22 is received in slot H8, as shown in Fig. 4, the carrier 48 isrestrained from movement. In such position the fuse holders l5, l8 and Ti are completely disconnected from the line and safety to the operator from high voltage is assured. Additionally,.the upperclips, namely, theiuse clips 64-;e1i'g'age' the contact blade I38 of the grounding device l3! and the safety of the operator is further assured; As the door opens, the check l29 prevents slamming of the door into open position. The links 94 engaging the flange 33 of. door 29 at the bottom of the samehold the door in the position shown in Fig; l. The fuses are now at the front ofthe opening 2| where the same may be inspected or exchanged as the occasion requires. If, during opening of the door, a flash-over occurs, the same is prevented from injuring the operator due to the barriers l34.- The dimensions of the carrier 48 are such that when the said carrier is in switch-opening position, as shown in Fig. 4, the said carrier substantially closes the openin 21 and prevents the operator from accidentally coming in contact withany of the live parts within the interior of the enclosure. At thesame time the grounding devices insure that the fuse holders are at ground potential. The weight of the link 94 causes the pin I04 to be received in the offset portion 33 of slot I02. Upon closing of the door the arm I05 is first moved upwardly due to the direction of thrust of the link 94 and lug I22 is disengaged from notch Hi3. When bolt H2 strikes lugs H3 movement of the arm :55 is terminated and further movement of the door causes-carrier 48 to swing about the axis of the hinge iii;

The carrier is then moved into position so that the blades 59 of the various fuse holders engage the switch jaws 9i and connect the fuses back into the circuits which they serve. If at any time, itbecomes desirable to leave the carrier 48 in switch-opening position, link 94 may be manually raised to disengage the pin IE4 from the offset portion ifi3 of slot I92. As the door is closed, the pin I84 then travels along the longitudinal portion H0 of said slot and the door 29 may be s d without interfering with th J in its switch-opening position.

The advantages of the invention are manifest. The structure is foolproof in operation and completely prevents high voltage accidents or hazards to the operator when changing or inspecting the fuses. It becomes impossible for the operator to inject his hand into the interior of the enclosure until after the switches have been opened and fuses disconnected. After the switches are opened, the carrier closes the access opening and the disconnected parts are then accessible'for inspection and exchange of-fuses. The structure shown is particularly applicable to high-voltage circuits. The switch and fuse construction embodying the invention can be constructed at a nominal expense and will operate indefinitely without requiring attention. Changes in the specific form of the invention, as herein described, may be made within the scope of .what is claimed without departing from the spirit of the invention. 7

Having described the invention, what is claimed as new and desired to be protected by Letters Patent is: 1. In combinatioman enclosure having an access opening therein, a door for said opening pivoted ,to said enclosure near an edge thereof and adapted to swing outwardly from said opening, a fuse carrier separate from said door disposed inwardly of said opening and pivoted to a part fixed relative to said enclosure and movable toward and from said opening, a fuse carried by said fuse carrier and having a fuse contact. an electrical terminal disposed inwardly of said access opening and fuse, a terminal con- 8. tac't'hohnected tosaid 'terininaland adapted to make contact with the fuse contact when the fuse carrier is in its innermost position and to become disconnected therefrom when the fuse carrier is'moved toward said opening, said carrier being of substantially the same area as the area of said access openin and serving to close said opening when the fuse contact is disconnected from the terminalcontact, and linkage between said fuse carrier and door, said linkage bringing saidcarrier into closing position when the door is in open position. 2. In combination,'an enclosure having an access opening therein, a door for said opening pivoted to said enclosure near an edge thereof and adapted to swing outwardly from said'op'ening, a fuse carrier separatefrom said door including a plate disposed inwardly of said open-,-. ing and pivoted to a part fixed relative to said enclosure and movable toward and from said opening, a fuse carried by said fuse carrier and" having a fuse contact, an electrical terminal dis-z posed inwardly of said access opening and fuse, a terminal contact connected to said terminal and adapted to make contact with the fuse c0ntact When the fuse carrier is in its innermost position' and to become disconnected therefrom when the fuse carrier is moved toward said opening, said plate being of substantially the same area as the area of said access opening and serving to close said opening when the fuse contact is disconnected from the terminal contact, and linkage between said fuse carrier and door, said link age bringing said carrier into closing position when the dooris in open position.

3. In combination, an enclosure having an access opening therein, a door for said opening pivoted to said enclosure near an edge thereof and adapted to swing outwardly from said opening, a fuse carrier disposed inwardly of said opening and pivoted to a part fixed relative to said enclosure and movable toward and from said opening, a fuse carried by said fuse carrier and having a fuse contact, an electrical terminal disposed inwardly of said access opening and fuse, a terminal contact connected to said terminal and adapted to make contact with the fuse contact when the fuse carrier is in its inner-- most position and to become disconnected therefrom when the fuse carrier is moved toward said opening, said carrier being of substantially the'same: area as the area of said access openingv and serving to close said opening when the fuse contact is disconnected from the terminal contact, a link pivoted to a'part carried by'said door and extending inwardly thereof, connecting means between said link and fuse carrier, said link being adapted to occupy two positions relative to said connecting means, said link in' one position being restrained from movement in the direction of its length relative to said fuse carrier to cause movement of the fuse carrier upon movement of said door, and in its other position being adapted to move in the direction of its length relative to the carrier to accommodate closing of the door when the fuse carrier isi'n its outermost position and the contacts are disconnected.

4. In combination, an enclosure having an access opening therein, a door for said opening pivoted to said enclosure near an edge thereof and adapted to swing outwardly from said opening, a fuse carrier disposed inwardly of said opening and pivoted to apart fixed relative tosaid'enclosure and movable toward andfrom' accuses said opening, a fuse carried by said fuse carrier and having a fuse contact, an electrical terminal disposed inwardly of said access opening and fuse, a terminal contact connected to said terminal and adapted to make contact with the fuse contact when the fuse carrier is in its innermost posit-ion and to become disconnected therefrom when the fuse carrier is moved toward said opening, said carrier being of substantially the same area as the area of said access opening and serving to close said opening when the fuse contact is disconnected from the terminal contact, a link pivoted to a part carried by said door and extending inwardly of the door, connecting means between said link and fuse carrier, said link being adapted to occupy two positions relative tosaid connecting means, said link in one position being restrained from movement in the direction of its length relative to said fuse carrier to cause movement of the fuse carrier upon movement of said door, and in its other position being adapted to move in the direction of its length relative to the fuse carrier to accommodate closing of the door when the fuse carrier is in its outermost position and the contacts are disconnected, and locking means acting between said enclosure and carrier and holding said carrier from movement when in its outermost position. v

5. In combination, an enclosure having an access opening therein, a door for said opening pivoted to said enclosure near an edge thereof and adapted to swing outwardly from said openi g, a fuse carrier disposed inwardly of said opening and pivoted to a part fixed relative to said enclosure and movable toward and from said opening, a fuse carried by said fuse carrier and having a fuse contact, an electrical terminal disposed inwardly of said access opening and fuse,

a terminal contact connected to said terminal and adapted to make contact with the fuse contact when the fuse carrieris in its innermost position and to become disconnected therefrom when the fuse carrier is moved toward said opening, a link pivoted to a part carried by said door and extending inwardly of said door, connecting means between said link and fuse carrier, said link'being adapted to occupy two positions relative to said connecting means, said link in one position being restrained from movement in the direction of its length relative to said fuse carrier to cause movement of the fuse carrier upon movement of said door, and in its other position being adapted to move in the direction of its length relative to the fuse carrier to accommodate closing of the door when the fuse carrier is in its outermost position and the contacts are disconnected, guide means carried by said en closure and engaging a part carried by said link, and lock means carried by said guide means and engageable with a part carried by said fuse carrier and holding the fuse carrier in its outermost position.

6. In combination, an enclosure having an access opening therein, a door for said opening pivoted to said enclosure near an edge thereof and adaptedto swing outwardly from said opening, a fuse carrier disposed inwardly of said opening and pivoted to a part fixed relative to said enclosure and movable toward and from said opening, a fuse carried by said fuse carrier and having a fuse contact, an electrical terminal disposed inwardly of said access opening and fuse, a terminal contact connected to said terminal and adapted to make contact with the fuse contact when the fuse carrier is in its innermost position and to become disconnected therefrom when the fuse carrier is moved toward said opening, a link pivoted to a part carried by said door and extending inwardly thereof, said link being formed with a bayonet slot having a longitudinal portion and an offset portion, a pin carried by the fuse carrier and movable along said slot, said pin when in said offset portion thereof causing movement of the fuse carrier upon movement of the door and when in said longitudinal portion accommodating sliding movement of the link relative to the pin when the fuse carrier is in its outermost position to close the door without causing movement of the carrier.

7. In combination, an enclosure having an access opening therein, a door for said opening pivoted to said enclosure near an edge thereof and. adapted to swing outwardly from said opening, a fuse carrier disposed inwardly of said opening and pivoted to a part fixed relative to said enclosure and movable toward and from said opening, a fuse carried by said fuse carrier and having a fuse contact, an electrical terminal disposed inwardly of said access opening and. fuse, a terminal contact connected to said terminal and adapted to make contact with the fuse contact when the fuse carrier is in its innermost position and to become disconnected therefrom when the fuse carrier is moved toward said opening, a link pivoted to a part carried by said door and extending inwardly of said door, said link being formed with a bayonet slot having a longitudinal portion and an oifset portion, an arm pivoted to a part carried by said fuse carrier, a pin carried by said arm and extending through said slot, and adapted to be received either the longitudinal portion of the bayonet slot or the ofiset portion thereof, a guide, a lug on said arm engaging said guide and movable along the same, said guide having a, notch therein near one end into which said lug may enter upon movement of the lug, said notch forming a shoulder restraining movement of said lug and preventing inward movement of said fuse carnor.

8, In combination, an enclosure having an access opening therein, a door for said opening pivoted to said enclosure near an edge thereof and adapted to swing outwardly from said opening, a fuse carrier disposed inwardly of said opening and pivoted to a, part fixed relative to said enclosure and movable toward and from said opening, a fuse carried by said fuse carrier and having a fuse contact, an electrical terminal disposed inwardly of said access opening and fuse, a terminal contact connected to said terminal and adapted to make contact with the fuse contact when the fuse carrier is in its innermost position and to become disconnected therefrom when the fuse carrier is moved toward said opening, a link pivoted to a part carried by said door and extending inwardly of said door, said link being formed with a bayonet slot having a longitudinal portion and an offset portion, an arm pivoted to a part carried by said fuse carrier, a pin carried by said arm and extending through said slot, and adapted to be received in either the longitudinal portion of the bayonet slot or the offset portion thereof, a guide, 3, lug on said arm engaging said guide and movable along the same, said guide having a notch therein near n end n o which a d lug m ente pon movement of the lug, said notch forming a shoulder restraining movement of said lug and preventing inward movement of said fuse carrier, said link being independently movable relative to said pin when the pin is in said notchto bring thepin into the longitudinal portion of the slot in the link for accommodating movement of the link independently of the fuse carrier to close the door.

9. In combination, an enclosure having an access opening therein, a door for said opening pivoted to said enclosure near an edge thereof and adapted to swing outwardly from said opening, a fuse carrier disposed inwardly of said opening and pivoted to a part fixed relative to said enclosure and movable toward and from said opening, a fuse carried by said fuse carrier and having a fuse contact, an electrical terminal disposed inwardly of said access opening and fuse, a terminal contact connected to said termina1 and adapted to make contact with the fuse contact when the fuse carrier is in its innermost position and to become disconnected therefrom when the fuse carrier is moved toward said opening, a link pivoted to a part carried by said door and extending inwardly of said door, said link being formed with a bayonet slot having a longitudinal portion and an offset portion, an arm pivoted to a part carried by said fuse carrier, a pin carried by said arm and extending through said slot, and adapted to be received in either the longitudinal portion of the bayonet slot or the offset portion thereof, a guide, a lug on said arm engaging said guide and movable along the same, said guide having notch therein near one end into which said lug may enter upon movement of the lug, said notch forming a shoulder restraining movement of said lug and preventing inward movement of said fuse carrier and stop means for restraining movement of said arm in one direction relative to said carrier to force said latch lug out of said notch upon initial movement of the door toward closing position.

10. In combination, a grounded enclosure having an access opening therein, a door for said opening pivoted to said enclosure near an edge thereof and adapted to swing outwardly from said opening, a fuse carrier disposed inwardly of said opening and pivoted to a part fixed relative to said enclosure and movable toward and from said opening, said fuse-carrier including a fuse clip, a fuse mounted in said clip, said clip having a fuse contact, an electrical terminal disposed inwardly of said access opening and fuse, a terminal contact connected to said terminal and adapted to make contact with the fuse contact when the fuse carrier is in its innermost position and to become disconnected therefrom when the fuse carrier is moved toward said opening, a grounding contact electrically connected to and carried by said enclosure and adapted to make contact with said clip upon disconnection of the fuse contact from the terminal contact, and linkage between said fuse carrier and door, said linkage bringing said carrier into closing position; when the door is in open position.

11. In combination, an enclosure having an access opening therein, a door for said openin pivoted to said enclosure near an edge thereof and adapted to swing outwardly from said opening, a fuse carrier disposed inwardly of said opening and pivoted to a part fixed relative to said enclosure and movable toward and from said opening, a fuse carried by said fuse carrier, a fuse contact in contact with said fuse, an electrical terminal disposed inwardly of said access opening and fuse, a terminal contact connected to said terminal and adapted to make contact with the fuse contact when the fuse carrier is in its innermost position and to become disconnected therefrom when the fuse carrier is moved toward said opening, said carrier being of substantially the same area as the area of said access opening and serving to close said opening when the fuse contact is disconnected from the terminal contact, barriers at the sides of said carrier and extending outwardly therefrom toward said opening, and a linkage between said fuse carrier and door, said linkage bringing said carrier into closing position when the closure is in open position.

12. In combination, an enclosure having a vertically disposed access opening, a door extending across said opening, pivot means for said door disposed substantially at the lowermost portion thereof, said door being adapted to swing through an angle greater than a fuse carrier disposed inwardly of said opening and normally extending in a rearwardly inclined direction with its lower edge disposed rearwardly of said door, pivot means for said carrier disposed substantially at the lowermost edge thereof and having its axis parallel to the axis of the pivot means for the door, and a link connected to said carrier and to said door and to the carrier at a greater distance from the pivot of the same than the distance from the pivot means for the door to the connection between the door and link, whereby the carrier is moved to a substantially vertical position upon the swinging of the door through out its extent.

13. In combination, an enclosure having an access opening therein, a door for said opening, a pivot for pivoting said door to said enclosure near an edge thereof, said door being adapted to swing outwardly from said opening, a fuse carrier planiform in shape pivoted to said enclosure near said pivot to swing outwardly in the same direction as said door, said carrier being disposed inwardly from said door, a fuse carried by said fuse carrier and mounted on the surface of said carrier facing said door, an electrical terminal disposed within said enclosure, a terminal contact disposed inwardly of said fuse carrier and connected to said terminal, a fuse contact'on the other surface of said carrier and normally engaging said terminal contact and linkage between said fuse carrier and door, said linkage serving to swing said carrier toward said access opening to disengage said contacts and move said fuse into accessible position when the door is opened. a

l4. In combination, an enclosure having'an access opening therein and being provided with a supporting structure extending inwardly from an edge of the opening, a door normally closing said opening, a first pivotfor said door disposed at said edge of the opening and attached to said door and supporting structure, said pivot guiding said door foroutward swinging movement to uncover said opening, a fuse carrier disposed within said enclosure inwardly of said door, a second pivot for said carrier having its-axis par.- allel to the axis of said door and disposed inwardly of said opening, said second pivot being connected to said carrier and supporting structure, a fuse carried by said carrier, a fixed teiminal, contact means between said terminal and fuse and adapted to be disconnected upon move merit of said carrierin an outward direction, and

linkage between said fuse carrier and door, said linkage serving to swing said carrier toward said access opening to disengage said contacts and move said fuse into accessible position when the door is opened.

l5. In combination, an enclosure having an access opening therein, a door for said opening, a first pivot for pivoting said door to said enclosure near an edge thereof, said door being adapted to swing outwardly from said opening, a fuse carrier, a second pivot between said carrier and supporting structure and supporting said carrier to swing outwardly in the same direction as said door, said carrier being disposed inwardly from said door, a fuse carried by said fuse carrier, an electrical terminal disposed within said enclosure, contact means between said terminal and fuse and adapted to be disconnected upon movement of said carrier in an outward direction, a link between said door and carrier, a third pivot between said carrier and link, a fourth pivot between said door and link, said third pivot being further from the second pivot than the distance between the fourth pivot and the first pivot whereby the door may be moved to a fully-open position while the carrier is being moved a distance suflicient to disengage said contacts.

JOHN S. FERGUSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,073,281 Palmer Sept. 16, 1913 1,402,123 Wadsworth Jan. 3, 1922 2,404,230 Harlow et a]. July 16, 1946

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