US1370656A - Protective device - Google Patents

Description

N. D. LEVIN.

PROTECTIVE DEVICE.

APPLICATION FILED OCT-20.1916.

Patented Mar. 8, 1921.

3 SHEETSSHEET WITNESSES.-

N. D. LEVIN.

PROTECTIVE DEVICE.

APPLICATION FILED OCT-20,1916.

1,370,656. Patentd Mar. 8, 1921 3 SHEETS-SHEET 2.

WITNESSES: M/VE/y 70/? MM W' $400 A TTOR/VE) N. D. LEVIN.

PROTECTIVE DEVICE.

APPLICATION FILED OCT-20, 1916.

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Wdneoom W UNITED STATES PATENT OFFICE.

NILS D. LEVIN, OF COL'QMBUS, OHIO, ASSIGNOR TO THE JEFFREY MANUFACTURING COMPANY, OF COLUMBUS, OHIO, A. CORPORATION OF OHIO.

PROTECTIVE DEVICE.

To all whom it may concern: Be it known that I, NJLS D. LEVIN, a citizen of the United States, residing at Columbus, in the county of Franklin and the State of Ohio, have invented certain new and useful Improvements in Protective Devices, of which the following is a specification, reference being had therein to the accompanyin drawing.

The present invention relates to certain new and useful improvements in protective devices, and especially in that class of protective devices by which the auxiliary electrical devices forming part of the circuit of the motors of mining machines are protected from accidental ignition of the gaseous atmosphere of a coal mine.

Although the greatest precautions are exercised to secure perfect ventilation in coal mines, there often occur such accumulations of gas as to render the atmosphere explosive. This is especiall true in the immediate neighborhood of the working face, where gas often escapes from the pockets and crevices of the coal seam in considerable quantities. The very nature of the case requires that the machinery which is employed for mining the coal should be most commonly used at the points most subject mine.

to gaseous atmosphere. It is, therefore, expedient that the electric motors by which these machines are actuated, and the accessory devices wherein electric sparks and flashes frequently occur, should be so inclosed and protected as to prevent the ignition of the gas in the atmosphere of the Sad experience has shown that the best safety devices are worthless if there is any possibility of their being disregarded by ignorant and heedless operators, and any protective device to be a real protection must be secure against the carelessness and ignorance of the people by whom it is used.

It is the especial object of this invention to provide a protective casing to inclose the electric fuses, or other circuit interrupting devices, used in connection with mining machinery, which shall prevent the ignition of the gaseous atmosphere of themine while affording convenient access for inspection and adjustment, effectively safe guarding against the ignorance and indifference of the operator of the machine.

The devices by which I attain this object are fully-set'forth in the following specifica- Specification of Letters Patent.

Patented Mar. 8, 1921.

' Application filed October 20, 1916. Serial No. 126,732.

tion and illustrated in the accompanying drawings, but it is to be understood that various modifications may be made as to details wlthout departing from the spirit of the invention.

Of the drawings- F igure 1 is a plan view of the preferred embodiment of my invention the cover bemg partly broken away to reveal the inter-- nal parts.

Fig. 2 is a section along the line 2-2 of Fig. 1.

Fig. 3 is" an end elevation of the device illustrated in Figs. 1 and 2.

Fig. 4 is a plan view of my improved protective device with the cover closed and locked.

Fig. 5 is a view similar to Fig. 4 showing the cover unlocked ready to be opened.

Fig. 6 is a side elevation showing the cover open.

Fig. 7 is an end elevation partly in section showing the application of removable plug cable terminals by which the devices within the casing may be connected with an external circuit.

Figs. 8 and 9 are fragmentary side elevae tion and plan views respectively of the devices shown in Fig. 7.

Like numerals refer to' similar parts in the several figures. 1

Referring to the drawings the numeral 1 indicates, as an entirety, the cast iron casing in which is mounted the apparatus to be protected against accidental ignition of the gaseous atmosphere of a coal mine. F or, the purpose of illustration I have shown a fuse cutout which forms a part of the electrical equipment of a mining machine, but it is apparent that such a casing may be applied 95 to the protection of any electrical device subject -to the formation of flashes which might ignite gas. This cut out is of the type commonly used with such apparatus and comprises, essentially, two fuse cartridges 2 100 the bottom. 4: of the casing is a slab 5 of 105 slate, or other approved fire and moisture proof insulating material, which constitutes the base upon which the electrical parts are mounted. A partition 6, composed of suitable insulating material, divides the interior 110 of the casing longitudinally, and separates the fuses of opposite polarity. Secured to ductor strips 13 with the terminal binding posts 14 and 15 to which are attached the conductor cables 16 and 17 leading to the motor circuit of the mining machine. To the brackets 8 are pivotally connected the switch blades 19, the outer ends of which are adapted to engage the contact blades 20 carried by the brackets 21 in the manner common to knife, blade switches. These brackets 21 are connected through the conductor strips 22 vei'th the terminal binding posts 23 and 24 to which are connected the conductor cables 25 and 26 leading from the source of electrical supply.

As the binding posts 14, 15, 23 and 24 are alike, a description of one of them will suffice for all. From the body portion 23 a stem 27 extends through the apertures 28 of the end wall 29 of the casing and to this stein is screw threaded a nut 30 which serves the double purpose of holding the binding post in place and of forming'the electrical connection with the strip 22. In the aperture 28 is snugly fitted an insulating bushing 31 having a flange engaging the inner face of the end wall 29 of the casing and serving to insulate the connecting strip 22 therefrom. Fitted over the projecting end of the bushing 31 is a tube 33 formed of some approved insulating material, having an internal flange 34 against which the binding post 23 abuts insuch a manner that when the nut 30 is drawn tightly into place the bushing 31 and the tube 33 will be drawn together to effectually seal the aperture 28, The binding post 23 is provided with a transverse aperture 35 into which the end of the conductor cable 25 may be thrust to be clamped tightly in place by the set screw 36. The walls of the casing 1 are extended beyond the end wall 29 to form a chamber 37 of suflicient size to contain the binding posts 14, 15, 23 and 24 andthe branching cables 16, 17 25 and 26 which connect with them. This chamber is closed in front by the plate 38' having apertures 39 through which the cables. pass, and these apertures are provided with flaring tubes 40 to protect the cables against abrasion.

The casing 1 is provided with a hinged cover 41 having a relatively broad flange 42 extending entirely around its edge. This flange is adapted to abut against a similar flange 43 formed on the upper edge of the casing 1 when in its closed position to form a flame proof joint. Formed on the casing 1 are lugs 44 and 44 towhich the pin 45 is ing.

At the end of the casing 1 opposite to the hinge are upstanding lugs 47 and in both these and the hinge lugs 44 and 44 are formed notches 48 adapted to engage with flange extensions 49 of the cover toprevent its rotation about the hinge pin when in the closed position. The lugs 46 are so spaced relative to the lugs 44 as to admit of su-f-.

ficient lateral movement of the cover to release the flange extensions. 49 from the notches 48, to allow the cover to be turned back to open the casing.

When the cover 41 is open, the edge 49 of the flange extensions 49 engages the hinge lug 44 to prevent lateral movement of the cover 41. Attached to the switch blades 19 are blocks 50 of insulating material which are engaged by the flanges 51 of the crank arms 52. These crank arms 52 are provided with trunnions 53 journaled in apertures 54 of the side plates 55 of the casing, to the outer ends of which are fixed the rocker arms 56 by the rotation of which the switch blades 19 may be rotated into or out of engagement with the contact blades 20. These rocker arms 56 are joined together at their outer ends by the cross bar 57 to afford a convenient handle for the manipulation of the switch. Both the crank arms 52 and the rocker arms 56 are expanded to form the flanges 58 which engage the faces of the side plate 55 to form flame proof seals for the apertures 54. The shape and proportions of the parts above described are such that when the switch blades 19 are in their closed circuit position the rocker arms 56.- will engage the edges of the flanges 42 to prevent lateral movement of the cover thereby maintaining the engagement of the flange extension 48 with the lugs 44, 44 and 47 to maintain a flame proof closure of the casing. When, however, the arms 56 have been retated far enough to clear the flange 42 and allow the necessary lateral movement of the cover, to release it for rotation about the hinge pin, the switch blades 19 will have been moved far enough to open the circuit thereby insuring against the accidental flanges one and a half inches wide will afiord a safe flame proof relief Vent for the pressure of an internal explosion, and afford sufiicient freedom of motion for the convenient manipulation of the cover plate.

It is often desirable in order to attain flexibility of handling that the conductors 16 and 17 shall be removably connected to the devices within the casing. For this purpose I have provided the plug terminals 59 and 59' of the well known, construction. As shown in, Fig. 7, the plug 59 consistsof a metallic terminal 60 soldered to the conductor '61 and incased' in an insulating sleeve 62. In this terminal 60 is formed a socket 63 adapted to engage with the upstanding stud 64 positioned in alinement with a suitable aperture 65 in the wall 66 of the casing 1. The stud 64 is supported by an insulator 67 fixed to a flange 68 of the casing 1 and is connected with the binding post 14 throu h the conductor strip 69.

Formed on the plug 59-is a flange 70 adapted to be engaged by the extension 71, formed on the flange 42, when the cover 41 is in closed position. The proportions of the flange extension 71 are such that when the cover 41 is moved laterally to its unlocked position the flanges 70 will be disengaged, permitting the withdrawal of the plugs to disconnect the cables 16 and 17. By this arrangement the plugs 59 and 59 are locked against removal at all. times when current is flowing through the cables 16 and 17 and the first step looking toward their withdrawal opens the circuit, thus insuring against the formation of arcs between the socket 63 and studs 64.

What I claim is 1. In a device of the class described, the combination of a casing, a hinge upon the casing,a cover both rotatable and slidable upon the hinge, a circuit breaker within the casing, and means made effective by sliding movement of the cover to prevent the opening of said cover while the circuit breaker is closed or the closing of the circuit breaker while the cover is open.

2. In a deviceof the classdescribed, the

combination of a casing, a hinge upon the casing, a cover both rotatable and slidable upon the hinge, means to lock the cover in closed position, a circuit breaker within the casing, and means made effective by sliding movement of the cover to prevent the unlocking of the cover while the circuit breaker is closed or the closing of the circuit breakerfi while the cover is unlocked.

3. In a device of the class described, the

combination of a casing, a hinge upon the casing, a cover both rotatable and slidable upon the hinge, means made eflective by sliding movement of the cover to lock said cover in closed position, a circuit breaker within the casing, a lever outside the cas-' ing to control the circuit breaker, said lever being so disposed as to prevent "unlocking the cover while the circuit breaker is closed or closing the circuit breaker while the cover is unlocked.

4. In a device of the class described, the combination of a casing,-a cover hinged to the casing, devices on the casing to engage the cover when in closed position to prevent rotation upon the hinge and releasable by lateral movement of the cover, a circuit breaker within the casing, a lever outside the casing to control the circuit breaker, said lever being so disposed as to prevent lateral movement of the cover while the circuit breaker is closed and to prevent reclos-v ing the circuit breaker before returning the cover to the closed position.

5. In a device of the class described, thecombination of a casing, a hinge upon the casing, a cover both rotatable and slidable upon the hinge, removable means to connect the devices within the casing to an external circuit, and means made effective by sliding movement of the cover to prevent the removal of the connecting means.

6. In a device of the class described, the combination of a casing, a hinge upon the casing, a cover both rotatable and slidable upon the hinge, removable plug terminals adapted to connect the devices within the casing with an external circuit, and means made efiective by sliding movement of the cover to prevent the withdrawal of the plugs while the cover is closed.

7. 'In a device of the class described, the combination of a casing, ahinge upon the casing, a cover both rotatable and slidable upon the hinge, a circuit breaker within the casing, removable plug terminals adapted to connect the devices within the casing with an external circuit, and means made effective by sliding movement of the cover to revent the withdrawal of the plugs whide the circuit breaker is closed.

8. In a device of the class described, the combination of a casing, a cover hinged to. the casing and adapted to limited lateral movement, devices on the casing adapted to engage the cover when in closed position to lock it against rotation upon the hinge, acircuit breaker within the casing, a ,lever outside the casing to control the circuit breaker, said lever being so disposed as to prevent lateral movement of the cover to release. the locking devices while the circuit breaker is closed, plug terminals adaptedto connect the devices within the casing with an external circuit and'flanges, on the plugs engageable by the cover when in closed position to prevent removal of the plug.

9. In a device of the class described, the combination of a casing, a cover 'for the casing, a circuit breaker within=the casing,

means made effective by lateral movement of the cover to prevent the opening of the cover while the circuit breaker is closed, and to prevent closing the circuit breaker while the cover is opened.

10. In a device of the class described, the combination of a casing, a laterally movable cover for the casing, a circuit breaker within the casing, a lever outside the casing to control the circuit breaker, said lever being so disposed as to prevent movement of the cover while the circuit breaker is closed, and means to prevent reclosing the circuit breaker while the cover is opened.

11. In a device of the class described, the

combination of a casing, a laterally movable cover for the casing, a c rcuit breaker, w1th1n the casing, means outside the casing to actuate the circuit breaker and adapted to prevent movement of the cover while the circuit breaker is closed and to prevent closing the circuit breaker while the cover is open. 7

12. In a device of the class described, the combination of a casing, a laterally movable cover for the casing, a circuit breaker within the casing, a lever outside the casing to control the circuit breaker, said lever being so disposed as to prevent lateral movement of the cover while thecircuit breaker 4 combination of a casing havingcontact devices therein, removable plug terminals adapted to connect said devices, respectively, with .an external circuit, and a cover for. the casing having a flange movable therewith independently of said connecting means and adapted to engage with said means and prevent their removal when the cover, is in closed position. a

15. In a device of the class described, the combination of the casing having contact devices therein, removable plugterminals adapted to connect said devices, respectively, with an external circuit, and a cover for the casing movable'laterally relatively thereto and adapted, when moving. laterally, to engage with said terminal'lugsand prevent their removal when the cover is in closed position 16. In a device oi the class described, the combination of a casing, a cover for the casing adapted to limitedlateralmovement, devices on the casing adapted to engage the cover to lock it in closed position, a circuit breaker within the casing means outside the casing to control the circuit breaker, said means being adapted to prevent the unlocking of the cover while the circuit breaker is closed and to prevent reclosing the circuit while the cover is unlocked.

17. In a device of the class described, the

combination of a casing, a cover for the casing adapted to limited lateral movement, devices on the casing adapted to engage the cover to lock it in closed position, a circuit breaker within the casing means outside the casing to control the circuit breaker, said means being adapted to prevent unlocking the cover while the circuit breaker is closed and to prevent reclosing the circuit breaker while the cover is unlocked, removable plug terminals adapted to connect the devices within the casing with an external circuit,. and means to prevent the removal of the plugs While the cover is closed.

18. In a device of the class described, the combination of a casing, a cover hinged to thecasing and adapted to limited lateral movement, a circuit breaker within the casing, removable means to connect the devices within the casing with an external circuit and means made effective by the lateral movement of the cover to prevent the removal of the connecting means while the circuit breaker is closed.

' 19. In a device of the class described, the combination of a casing, a cover hinged to thecasing and adapted to limited lateral movement, a circuit breaker within the casing, removable plug terminals adapted to connect the devices within the casing to an external circuit, and means made effective by the lateral movement of the cover to prevent the removal of the plugs while the circuit breaker is closed.

20. In a device of the class described, the combination with a casing of a cover hinged to the casing and adapted to limited lateral movement, devices on the casing adapted to engage the'cover when in closed position to lock it against rotation upon the hinge, removable plug terminals adapted to connect the devices within the casing with an external circuit, and means made effective by the lateral movement of the cover to prevent the withdrawal of the plugs while the cover is locked.

21. In a device of the class described, the combination of a casing, a laterally movable cover for the casing, a circuit breaker cover while the circuit breaker is closed or one direction to close the casing and in a direction angular thereto to lock the cover closed, a circuit breaker within the casing, and means to prevent unlocking the cover while the circuit breaker is closedor closing the circuit breaker while the cover is unlocked.

23'. In a device of the class described, the

combination of a casing, a cover movable in locking the cover while the circuit breaker 15 is closed or closing the circuit breaker while the cover is unlocked.

In testimony whereof I afiix my signature, in the presence of two witnesses.

NILS' D. LEVIN.

Witnesses: K

DUDLEY T. FISHER, HARRYO. DEAN.

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