US996267A - Electrically-operated hoisting apparatus. - Google Patents

Description

F. B. LUTZ. ELE'GTRIGALLY OPERATED HOISTING APPARATUS.

Patented June 27, 1911.

2 BHEETB-BHEBT 1.

APPLICATION FILED JUHEB, 19091- INVEIVTM JTTQRIVEYS WI THE $61535 F. E. LUTZ.

ELEGTRIGALLY OPERATED HOISTING APPARATUS.

APPLICATION FILED JUNIH! 1909. 996,267. A Patented June 27,1911.

2 SHEETB-BHBBT 2.

INVE/Vmfl M BY WITNESSES:

"UNITED STATES PATENT OFFICE.

FRANK EDWARD LUTZ, OF PHILADELPHIA, PENNSYLVANIA.

ELECTBICALLY-OPERATED HOIS'I'NG APPARATUS.

Specification of Letters Patent. Patented June 27, 19 [1.

Application filed June 8,

1909. Serial No. 500,877.

To all whom it may concern:

Be it known that I, F RANK EDWARD LUTz, a citizen of the United States, residing at Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented a new and useful Improvement in Electrically- O aerated Hoisting Apparatus, of which the to lowing is a full, clear, and exact description, reference being had to the accom anying drawings, which form a part 0 this specification.

My invention relates to certain iin rovements in limiting the movement 0 machinery or apparatus propelled by electric motors, as, for instance, the limiting of the lifting or lowering of hoisting apparatus or the limiting of the vertical or horizontal movement of other moving apparatus.

Particularly, the invention relates to a three point switch with switch blade pivoted at one point and the switch operating arm pivoted at the same point and providing a projection or trip for opening the operating arm. The switch may either be placed on the moving member and the trip on a fixed point or vice versa.

Further, the invention relates to certain electric circuits controlled by the switch, whereby in one osition of the switch the current can pass 1n one or an opposite direction to the motor while in another position of the switch it can pass in one direction only.

Further, as particularly applicable to a hoisting drum, it relates to a trip mounted upon the drum and having its operative po sition determined by the winding of the rope upon the drum.

This, and certain details of construction of the trip and other mechanism, generally speaking, form the subject-matter of my invention.

I will now describe the embodiments of my invention as applied to a hoisting apparatus, as shown in the accompanying drawin and then point out the invention in the c aims.

In the drawings: Figure 1 is a dis rammatic view of the electric circuits. *ig. 2 is an elevation of a hoisting drum, etc. Fig. 3 is a detail view of switch and trip, etc.

Fig. 4 is a similar view with switch in another positicn. Fig. 5 is a side view of switch, etc Fig 6 1s an elevation of another view of trip. 1g. 7 1s a plan view of trip of Fig. 6.

a isthe winding drum, 7) the motor, a a gear on the motor shaft, 65 a large gear on shaft (2 with which gear a meshes, f a small gear on shaft 0 meshing with gear g on drum shaft h.

j is the armature of the motor and 7c the field i l is the reversing switch, in the lead wire from one pole of current supply and n the lead wire to the other ole. is interposed a contro ling switch having the spring cont-acts o and p in electrical conncction with wires of the circuit. In addition to the contacts 0 and are the somewhat tighter contacts 9 an 'r, the pur ose of which will hereinafter be fully descri ed.

The switch proper consists of the blade 8 to which one wire of the circuit connects and the circuit passes through the blade to the one of the contacts 0 or p to which the blade is connected. The blade is pivotally mounted at 19.

t are projections from the blade to each of which is connected a spring 11.. The other ends of the s rings are connected to the de pending por ons c of the yoke w. The yoke w is centrally connected to the arm 3 also pivoted at w and having on its outer end the heart cam 2.

As may be seen, when the arm y is moved in one direction it throws one of the springs u into tension and when the depending por- -,tion '0 strikes the blade andmoves it sutliciently to free the blade from the contacts, the tension of the spring is sufficient to snap the switch blade across the space between contacts and into electrical connection with the other contact. The springs, also, after this, bring the operating arm to normal position.

The auxiliary spring cli s or contacts q and r insure the pro er ho ding of the contact with blade unti the action of the dcending portion 0 positively ,moves the blade. This switch is mounted near to the drum so thatthe cam z is in line with a trip mounted on the drum in one position of the trip. This trip consists of the trip proper 7 of heart shape on the end of the arm 8, having the projecting tongue 9. The arm 8 is pivoted to the frame 10 and a spring 11 it normally in inoperative osition. stand 10 is fixedly mounte so that the tongue 9 is in line with the groove in the drum, so that the rope 200 entering this In this circuit connects the trip with the frame to retain The.

. .in Fig. 1, and the grooves ,drum can continue to descend.

groove will bear against this tongue and move the trip into alinement with cam This tongue is generally placed in line with the groove corresponding with a point just before the limit of the winding.

The controlling switch being in the position shown infull lines, Figs. 1 and 3, and

osition shown eing free, the spring 11 holds the trip in the position shown in Fig. 2. The current then passes through the circuit, Fig. 1, as indicated by the full arrows. The motor is then operated to rotate the drum to wind the cable. \Vhen the cable reaches the groove in the drum in line with which the tongue on the trip rests the cable will move the tongue downwar against the action of the spring. This will bring the cam of the trip in line with the cam of the switch as shown in Fig. 5. Further movement of the drum will cause the cam of the trip to move, the cam of the switch (see Fig. moving the arm and expanding one of t \e s rings u. The blade will then be positive y moved by the depending portion 4; of the okew until moved free from the auxiliary c ips v and r orfree from the clips when the springs will snap the blade across the gap to the opposite contacts. The springs wi 1 also return the o crating arm to operative position when tie cam trip passes beyond it. The position of the arm and the blade in this position is shown in Fig. 4 and the position of the blade in dotted lines, Fig. 1. With the blade in this position shown in Fig. 1, no current will ass to the motor with the reversing switcii in its initial position for operating the reversing switch in the the motor to rotate the drum-to wind the.

cable (see full arrows). When, however, the reversing switch is reversed to allow the motor to revolve to rotate the drum to unwind, the current will pass as indicated by the dotted arrows, Fig. 1. By this arrange ment it is impossible, after the trip has actor], to operate the reversing switch except to cause the motor to operate in the opposite direction, a. 0., to unwind the rope.

As soon as the drum moves to unwind, the tri i will act to operate the controlling switch ant bring it back to its initial position, Fig. l, the trip passing beyond the cam e of the arm 5: of this switch. The blade then contactswith contact q. The wiring in this position is such as to allow the current to continue to pass in the same direction as with the blade in contact withcontact and the QVhen the rope passes frolncontaot with the tongue of the tlipin the movcmcntof the drum to an wind, the spring moves thetrip to inoperative position where it remains until again brought into action by the cable in the retation of the drum to ascend.

The trip device shown in Fig. 6 is one that may be used and has the advantage over the trip shown in Figs. 3 and 4 in that of making certain the return of the blade of the controlling switch, which would not occur in the switches of Figs. 3 and 4 if the tri failed to pass beyond the cam on the on of arm y. This trip consists of a. heartshaped cam 12 like that of Figs. 3 and 4, which forms part of a frame 13 having a cut-away portion between cam 12 and projection 14. This rojcctionhas a spring blade 16 connected to its rear surface to which is connected a pin or projection 17, projecting through an orifice ii -line with the active face of cam 12. This frame 13 is pivoted to a bracket or frame 15 and also connected thereto by spring 27. The frame 13 has also a tongue 18. The bracket is supported so that the tongue 18, like, the tongue 9 of the trip shown 1n Figs. 3 and 4, will be in line with a groove in the drum. The frame 13 is brou ht into action by the cable pressing upon tie tongue and moved out of action by the spring;

As may be seen, in the winding of thfeflrum if for any reason to the cam 7 of should not pass beyond the cam z in t 0 reverse movement of the drum, the in 1 will strike the cam a and bring the b ado of the cont rolling switch back to its initial position.

Havin now fully described my invention, what I c aim and desire to protect by Letters Patent is 1. In an apparatus of the character described, a controlling switch device comprising. in combination, two contacts, a pivoted switch blade adapted to swing from one contact to the other, a pivoted arm, projections thereon, one adapted to engage said blade and move it from its position of tight engagement with one contact toward the other contact, and the other adapted to engage said blade and move it from its position of tight engagement with the second contact toward the first contact, and a. spring connccting said arm and said blade adapted to be thrown into tension during the movement of the arm until one of its projections engages and releases the blade and tethereafter snapsaid blade into engagementwith the other contact.

the cam 12, corresponding the trip of Figs, 3 and 4,

2. In an apparatus of the character de scribed, a controlling switch device (asap 1S-' ing, in combination, two contacts, a 1 0 d switch blade adapted to swing from one contact to another an arm pivoted on the'axis of the switch blade and normally occupying a position parallel thereto when the switch blade is engaged with either contact, means to swing said arm from one to the other of its normal positions, a sgringconnecting said arm and blade adapts to be thrown into tension during the swinging movement of the arm, and means on thearm adapted'during its movement to engage and move said blade out of tight engagement with its contactthereby permitting the spring to act to throw said blade into engagement with the other contact.

3. In an apparatus of the character described, a controlling switch device comprising, in combination, two contacts, a pivoted switch blade adapted to swing from one contact to another, an arm pivoted on the axis of the switch blade and normally occupying a position parallel thereto when the switch blade is engaged with either contact, means to swing said arm from one to the other of its normal positions and projections carried on opposite sides of said arm and springs connecting said blade with the res ective projections, said blade being in line 0 travel of one of said projections when the arm is swung as aforesaid; whereby the blade is first moved from tight engagement with one contact by means of said projections and then snapped toward the other contact by the spring that is thrown into tension during the movement of the arm..

4. In an apparatus of the character described, a controlling switch comprising, in

combination, two sets of contacts. each comprising a contact adapted to hold the switch blade relatively loose and one to hold it relatively tight, a pivoted switch blade adapted to swing from one set of contacts to another, a pivoted arm, projections thereon adapted, toward the completion of the swinging movements of the arm, to engage said blade and release it from the tight contacts respectively, and a spring connecting the arm and the blade adapted to be thrown into tension during the movement of the arm to snap the blade, after its release from a tight contact, out of engagement with the corresponding loose contact and into engagement with the other set of contacts.

In testimony of which invention, I have hereunto set my hand, at Philadelphia, on this 4th day of June 1909.

FRANK EDWARD LUTZ.

Witnesses M. M. HAMILTON, A. M. URIAN.

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