US1145899A

US1145899A - Ammunition-hoist.

Info

Publication number: US1145899A
Application number: US737276A
Authority: US
Inventors: John D Ihlder
Original assignee: Otis Elevator Co
Current assignee: Otis Elevator Co
Priority date: 1908-06-12
Filing date: 1912-12-17
Publication date: 1915-07-13
Anticipated expiration: 1932-07-13

Description

J. D. IHLDER.

AMMUNITION HOIST.

APPLICATION HLED DECJY, I912.

11, 145,899. Pafented July 13, 1915.

4 SHEET$SHEET I.

C ME UQK QQA WITNESSES: l/VI/E/VTOR ATTOI? EV 1. 0. IHL DER.

AMMUNH'ION HOIST. APPLICATION FIL ED DECJT, 1912. 1,145,899. Patented July 13, 1915.

4 SHEETS-SHEET 2.

I 00 7f WITNFSSEQ: INVENTOR ATTO EV J. D. IHLDER.

AMMUNITION HOIST.

APPLICATION man 050.17.1912.

1,145,899, Patented July 13, 1915.

4 SHEETS-SHEET 3.

. I BV/Z 452352? 1. DIIHLD ER.

AMMUNITION HOIST. APPLICATION FILED DEC. 17, I912.

1,145,899,, Patented Ju1 13, 1915..

4 SHEETS-SHEET 4- W/TIME 95958. INVENTOR EJWETED S'idfiii FATENT @FFECE JOHN D. IHLDER, OF NEW YORK, N. Y., ASSIGNOR T OTIS ELEVATOR COMPANY, OF

JERSEY CITY,

NEW JERSEY, A CORPORATION OF NEW! JERSEY.

AMMUNITION-HOIST.

Specification of Letters Patent.

Patented July 13, 1915.

Original application filed Jane 12, 1908, Serial No. 438,030. Divided and. this application filed December 17, 1912. Serial No. 737,276.

To all whom it only, concern Be it known that 1, JOHN D. InLDnn, a citizen of the United States, residing in New York, in the county of New York and State of New York, rave invented a new and useful Improvement in Ammunition-Hoists, of which the following is a specification.

The present invention relates to hoisting mechanism and electrical operating and controlling mechanism therefor, and is more particularly adapted to ammunition hoists of that type in which the ammunition is lifted by a carrier to a position opposite the breech of the gun. and the carrier held in its elevated position by means of a reduced current supplied to the hoisting motor.

The present case is a division of my copending application for patent on ammunition hoist contr l Serial No. 438,080, filed June 12, 19133.

Referring to the accompanying drawings, Figure 1 is an clcvatioual view of a gun and ammunition hi'iisting mechanism; Fig. 2 is a view showing mechanism for simultaneously adjusting the gun elevation and the position of the butter; Fig. 3 is a rear eleration of the buli'er and ammunition carrier; Fig. 4 a diagrammatic view of the electrical system of control; Fig. shows a modification of the controlling mechanism adapted to a shunt wound motor.

The invention herein shown in connec tion with a gun as used on a war vessel.

The gun G is mounted in a rotating turret T supported on rollers 1 adapted to travel on a track 2 on the framework The gun is mounted on its carria e in the usual way by means of horizontal trunnions 5 journalcd in the gun carriage. The ammunition is elevated from the hold of the ship to the gun by a car or carrier C adapted totravel on the tracks (3. The upper ends of these tracks are fixed to the turret and the lower ends are secured to a frame 7 rotatable with the turret so that the tracks retain a fixed position relative to the gun carriage. The carrier C is lifted and lowered by means of a hoisting rope or cable 8 connected at one end to the carrier and extending up and over the guide sheaves 9 and 10 and down to the winding drum 11. A gear Wheel 12 connected to the winding drum meshes with by springs 17 form the driving pinion 13 on the shaft of the hoisting motor M.

An adjustable buffer B is located near the upper end of the tracks 6 in position to form a stop for the carrier at its upper limit of travel. This butter comprises a cross beam ll and guides 15 slidable vertically on the rails 6. Abutments l6 normally projected yielding stops for the carrier C.

The mechanism for adjusting the elevation of the gun comprises a bracket 18 bolted to the under surface of the turret floor, and having a hollow cylindrical body portion to receive a rotatable member 19. A. miter gear 20 on the upper end of the member 19 meshes with a pinion 2.1 on the shaft of an electric motor A. A screw-threaded rod 22 works in a. threaded recess in the member 19. A connecting rod 23 is connected at its lower end to the rod 22, and at its upper end to a bracket 2i on the gun. The operation of the motor A will effect an adjust1nent of the gun elevation in an 0-bvious manner.

This mechanism 720/ so is not my invention. The following means, however, in combination with such mechanism for ai'ltomatically adjusting the position of the butter ll as. the gun elevation is adjusted, forms a feature of the present invention. A screw-threaded rod 25 is swivcledin a crossbeam 26 which is secured to the rails. The rod 25 is held against vertical movement by disks 27 secured to the rod on opposite sides of the beam 26. An internally screw-threaded sleeve 38 receiving the rod 25, is secured to the cross-piece 14 and forms-a supporttherefor. A power-transmitting rod 29 supported in any convenient manner has a beveled gear 30 at its upper end meshing with a gear 31 on the lower end of the rod .he rod 29 is geared to the motor A by means of pinions 32 and 33 and a gear wheel 34-. When the motor A is operated to adjust the gun elevation, the shaft 25 will be rotated by means of the gearing just described, and as said rod can-- not move vertically the sleeve 38 and butter B will be moved up or down, depending on the direction 01' rotation of the motor armature. The gearing is so arranged and proportioned that the buffer moves up and down with the breech of the gun and to substantially the same extent, so that whatever the gun elevation may be the buffer is in position to stop the carrier C with the charge in proper position for loading.

In connection with the buffer B, I have shown an electromagnetic locking device L adapted to lock the carrier C'in its elevated position during the loading of the gun. This An automatic fioor controller F is connected for rotation to the motor M, or some movable partof the hoistingmechanisml As shown in' Fig. 1, the controller F is providedwith a sprocket wheel -10 geared by a chain 41 to a sprocket wheel 42 on theshaft of the hoisting drum, so that the controller ill move in unisonwith the carrier (I. As

shown diagrammatically in Fig. 4 the controller carries a series of arc-sluiped movable contact strips 4-3, 44, 45, etc., adapted to engage a series of stationary brushes 49, 50, etc. The brushes. or those'controlling the motor. circuits as the carrier 1 is lifted may he carried by an arm 62 iournaled at one end on the shaft of the controller. A rope. or cord 63 is connected at one end to the arm (52 and pas is over direction sheaves (34, (35 and is secured at its other end to the gun. A coil of spring (36 keeps the rope (S3 taut. The position of the brushes carried by the arm (32 will therefore he changed.whenever;

the gun elevation is changed, and the arrangement is such that the relative pos1- tion of the brushes and contact strlps is al- 'ays substantially the same for any given,

position of the carrier C relativelyto; the butter Hand breech of the gun. The specific construction of the controller F may be the some as that fully shown and descrihed in my former Patent N o. 879,387, datedFebru ary 1%, 1908. If'iti's desired to give the controller more than one revolution. the construction disrioscd in. my Patent No.711h914, dated October 7, .1902, may housed,

in Fig. l the controller F shown in the position assumed when the car (I is at its normal upper limit of travel. The lever of the car switch S has been brought to center and the machine is at rest with the car held hy the locking device ll. The power is cut oil" from all parts except the brake magnet. To start the car on its downward travel from this position, the car switch handle is moved to the right to bring the-contact plate 71 into engagement with the stationary contacts (if). 76. 77 and 78. his assumed that the car is not sufiiciently heavy to over-come the friction of rest of all the parts, but that after being set in motion it will accelerate and continue running downward without re quiring power from the source of supply.

The circuits established are as follows: from the plus line (37 through conductor 8 to car switch contact (3!), plate 71. and contact 70, through

conductors

158, 158, contact (31 on controller F, plate 48, contact. 3 conductor 16]., coil 15? of the double magnet X, conductors 1G2, 159. 128, contacts IR? and condluqtors 127 to the minus line (11.. l'lhe magnet X being thus excited its'core is lifted. making connection between the

contact

100 and 163 .and thereby closing a main .the

circuit through the motor. which circuit is from the plusline to the armature brush 98, through the armature 9?. brush 9G. conduc- 110F165, switch 160, coil 11313 of magnet 11M, and. resistances 167 and 1138 to the minus line. The switch 160 is losed at. this time since its nlagnet'spool 1513 is encrgized.heing in a parallel circuit with the spool 157 of magnet X which. circuit may be traced from the conductor- 15Sv through spool 1515, conductors 15!), 128, contacts 187. and conduc tor 127 to the minus line. llll'mlt is admitted to the brake magnet 112 by way of car switch contact 7Tv through conductor 1553, contact 49, spiral 15. contact 50, conductor 111 to the brake spool 112, and through conductor 91 to the minus line. A parallel circuit through the brake magnet may be traced from the plus line through conductor 150, contact 55, conductor. 151, contact spiral 46, contact 51, conductor 152, re sistance 153to conductor 111 and the brake coil 112. The purpose of this latter circuit lever of theswitch S over to the right is to.

release the locking device L and supply current to the armature in a direction to start the carrier downward. This current is only. suppliedduring the iniiial down \vard.movcmcnt of the carrier, however, and is for the purpose of overcon'iing the excessive starting friction which in some cases the weight of the carrier may not be able to overcome. The carrier now commences its tac t downward movement and the increasing speed of the armature quickly develops suiii- (-ient counter-electro-n1otive force to cause the lower magnet 169, which is connected across the armature, to pull its core down against the pull of the upper magnet 157. The contact strip 48 also leaves the brush when the carrier has moved downwardly a short distance and opens the circuit through the upper niaget 157, thereby limiting the distance the car can travel before the magnet is operated. The operation of the magnet 169 opens the circuit from the main line through the motor armature at the contact 163 and closes a local circuit through. the armature. This latter circuit may be traced from the armature brush 98 through conductor 99, contacts 100, .101, field coil 102, resistances 103, 105, coil of magnet 95, resistances 106, 107, con ductor 8Q,

resistances

168, 107, coil 160 of the load n'iagnet LM, switch 100, conductor 165 to the armature brush 06. The car now drires the motor as a generator and the current in this local circuit produces an electrodynaznic braking eii'ect which limits the speed of the car in its descent. The magnet acts during the descent of the car to regulate the speed for different loads. That is, if the load is heavy and accelerates the motor above a j )1'l%l811ljlllld limit, the magnet 95 recs s sutlicient current to close the switch 108 and short-circuit the resistance 107,

thereby increasing the current in the local,

a circuit thus incrcr lug the electrodynainic braking action rll'icientl to bring the speed down again. If the load is light, it will not tend to produce an excessive speed and the agnet will not operate to SilOi'i-(fll'Clllt the resistance 107, and the brakng action will he correspondingly limited. 1 a heavy load has caused the magnet 95 close the switch 108 and as a result the d falls below a given limit, the magnet c5 be weakened and the switch will open i ain to redi-tce the braking eil'cct. The l. magnet lull operates a switch 180 in the si me way to control the resistance 1G7,

that the speed regulated during the descent of the carrier and kept subs antially the same. or within predetcrmined limits for different loads.

As the car descends, the spiral contacts of controller l are turned in a clockwise :tion and when the car reach s a point s travel where it is necessary or desirto redi-tcc the speed temporarily, a1 iIZ'lJlP, wl it has to pass over a in the tracks or through a port, the spiral t? makes connecthe col'itai'ts 177 and 17 This t coil 175 into a. circuit nurture as follows, from the brush Eli: through condimtors 1G5,

- V 1a., magnet cm: 1

a, conductor 179, contact &

170, spiral l7, contact 177, and

conductors

180 and 99 to the brush 08. The magnet coil 175, if the speed of the armature is suliiciently high depending on the load, closes the switch 181 and short-circuits the resistance 168 which is at this time in the local circuit of the motor armature. The clectrodynaniic brake action is thus increased and slows down the carrier until the obstruction has been passed, when the spiral at? leaves the brush 177 and opens the circuit through the magnet coil 175 to rein sert the resistance 10S and permit the motor to run up to full speed again. During the descent of the carrier, the controller F"1nal es somewhat less than a complete revolution. The first step in slowing down the motor as the carrier approaches its lowermost position takes place when the contact strip 47 of the floor controller reaches the position where it bridges the contacts and 57. This closes a circuit from the positive main through conductor 150, brush 55, strip -ll7, brush 57, conductors 117, S2, coil of magnet FS, and conductor 81 to the negative main. The magnet FS now closes the switch S7 andshort-circuits the rcistanccs 106 and 107, increasing the clectro-dynamic braking effect and slowing down the motor. The next step in the control of the motor occurs when the strip 47 reaches the brush 58, the strip -l7 still rotating clockwisef This establishes a circuit from the positive main through coruluctor-150, brush 55, contact strip %7, brush 58, conductor 85, coil of magnet SS, and conductors 80 and M to the negative main. .l.he magnet SS closes the switch and short-circuits the load mag not LM, resistances .107, 108 and the magnet 95, leaving only the resistances 103, 10-1, 105, and the series field coil 102, in circuit with the motor armature. The clectro-dymui'iic braking cll'ect is now very pmvcrl'ul and slows down the carrier so that it comes quietl to rest in its lowered position. This removes the driving power for the motor, and the dynamic braking action quickly brings the motor and hoisting mechanism also to rest. In case the motor does not stop immediately, a slight further movement scp arates the spiral -15 and contact if) of the controller F and interrupts the circuit of the brake magnet .12, so that the brake assists in stopping the motor. (lcncrally the dynamic brake action will be sulucient to cll'ect a prompt stop without the nuvchauical brake being applied. he car sw tch haucllc ma then he brought to the stop position.

To lift the car, the handle ol the car switch H turned to the left, causing the contact plate 71 to lllzllit connection between the contacts 70, 7 73, 7-l and 75. This magnet spool i), an conductor 1 to the Ininus line. The in: i linev magnet closes the switch 92, establishing a motor circuit from the plus line through switch 92, conductor 93 to arn'iaturc brush 96, through the armature 9?, brush 9S, conductor 93), eon tacts 10% Ml, conductor .12 3, series tield winding .102, resistances .103, 104, 105, spool and resistances 106, 107 to the minus line. Another circuit is made from tlie plus line through conductor '35, contact 71 plate 7], contact 73, conductor lit, contact 50, conductor 1.11, brake spool 112 and conductor 9.1 to the minus line, energizing the spool and lifting the brake. A. connection is also made through the previously traced cmuluctors to plate Tl. contact Tl, condul'rtor 115, contact 54, spiral 43, contact 5! conduc tors 1'10, 117, Rid, through the winding oi. the magnet FS and lo the minus line. This energizes the magnet Fri and closes the switch '87. A further circuit made at the car switch ma be traced from the plate 71 through contact 7 coiuln-;:t;or lli contact 53, spiral 44', contact 56, conduzj'tor 120, accelerating inagz nct spool 11F conductor 121 to the junction me, which ener i'lm; the acceleratinn' znagruct spool according to the potential oi the motor armature. 'ihe magnet Fh'. having: closed the switch thercby shortcircuiting the

rcaisianr M

3 and 107, has reduced the starting resiatance to the amount contained in the series held 102, resistances 103, 1 H, 10 3 and the spool 95. 'lhcsc res 'taln'r-s are H4) proportioned that the current admitted y them will start the maxin'uun load.

As the speed of the and the accelerating magnet gradually increaees in power, it first closes the witch 123, shorhcircuiting the resistance .10 g and as the speed further inerc s the switch 124- is closed to slmrtmim-uit the ronistance 10-1; and linally the switchlzfi is closed to short-circuit the resistance 11);}. The closing ol the switch. .125 also brings the auxiliary contacts 12!), 1130 together and thereby establishes a circuit for the spool 131, which operates to close the switches 137 and 13S, short-circuiting the series field 102. The imlgznctization ol" the motor depends now on the shunt field winding 113 only, the latter being connected between the plus and minus lines by the conductors 114 and 8h. The motor now reaches maximum speed, the starting! resistance being all shortcircuitcd. 'lln armature circuit at this time is as follows: from the plus line through contacts 02, conduct-or 93, armature brush 1J8, armature 97, brush 98,

contacts

100, 101, conductor 1-1-1, contacts- 138,

coinluctors

143, 141, 122, switch 125, conductor 1%, contacts 187 and conductor 127 to the minus. line.

During the upward travel of the car, the spirals of the controller F move in an antimemes clockwise direction. When the car reaches the hatcl'nvay or position for which a slower speed is desired, the spiral 48 makes connection between the contacts and 183, energizing the spool 182, which opens the normally cloned switch 187 and introduces the resistance 188 in the armature circuit, thereby reducing the speed of the motor. After the car has passed such position, the spiral 48 breaks connection between the contacts 184 and 183, deenergizing the spool 18: closing the switch 187, and permitting the motor to again attain full speed. As the car approaches the upper limit of its travel the spiral -14 breaks connection between the contacts 52-3 and 513, interrupting the circuit of the accelerating magnet 115w, causing the switches 123', 12% and 125 to open, introducing the resistances 1103, Int, 105 and also the spool 95 into the armature circuit, and thereby reducing the speed of the armature. The switch S7 is closed at this time and the resistances 1G6 and, 10? therefore. short-circui'ted. The current through the magnet 35 which has just been excited by the operation oi the accelerating magnet, is proportional to the load being lifted by the motor, and this magnet is so designed. that with a heavy load it will e-lose the switch 108, but with a light load the switch 108 will remain open. The second step in slowing down the motor takes place when the controller has rotated a short distance farther and the contact strip 43 runs oil the brush 539 and opens the circuit through the magnet FS. This etiecte the opening of switch S7 and introduces the. resistance. 106 into the armature circuit, and if the load is light so that the magnet 95 has not ()ptl'ilttd, the resistance 107 also connected in the armature circuit, but if the load is heavy and. the magnet 9-5 has closed the ewitch 108 the resistance 107- will remain short-(tircuited. through the motor armature is thus further reduced an amount depending on the. load, less resistance being introduced when the load is heavy. It is thus seen that the mag net 95 and resistance controlled thereby form a means for varying the current in the mo tor in accordance with the-loadthe latter is being brought to rest at its upper limit of travel. Although the magnet 95 provides for only one *ariation in the current, it is obvious that the number of magnets and resistances may be increased to secure any degree of refinement of control desired. The speed of the motoris now reduced so that the carrier C is mo in" slowly as it is brought up against the butler B and come-s to rest without any undue jar or strain on any of the parts. The hook or catch 35 carried by the butter will be engaged by the carrier as the latter is being brought to rest and holdthc came until the hook is released by its magnet. f

. The current In order to insurethe brake being 01f during the time the carrier is opposite the gun, the following means may be provided: A contact strip d6 on the floor controller is so located as to engage the brush 52 when the carrier reaches the lowest position of the breech of the gun. This closes a circuit through the brake magnet, which may be traced from the positive main through conductor 150, conductor 151 brush 52, contact strip 4:6, brush 51, conductor 152, resistance 153, conductor 111, bra-ks magnet coil 112,- and conductors 91, S4 to the negative main.

This circuit is entirely independent of the manual switch S and is maintained until the carrier has descended below the gun. The operator is thereby prevented from opening the brake circuit and applying the brake to the motor when the carrier is moved while locked to the buffer. lVithout this provision the brake might be applied when the carrier was locked to the bufi'er and the breech of the gun then moved, carrying with it the buffer and carrier C which would be forced dowzr'against the holding power of the brake. Or, the carrier might be raised when the brake was applied, thereby producing slack in the hoisting cable so that the carrier would drop when the brake was re leased. In either case, the cable might be broken or other injurious results follow.

In some cases it is not only necessary to provide suflicient torque to hold the car, but a surplus torque must be provided to enable the motor to follow up the movement of the gun. In order to give the motor this additional torque with the least increase of current I make use of the magnet 131 which has short-circuited the series field. this magnet being connected to the terminals of the motor armature through the circuit which has been traced. When the connection was made during the acceleration, the motor had nearly reached full potential. This magnet is designed to hold the

switches

137, 138 closed until the motor has nearly .come to rest. when it Will open said switches, introducing the series field into the circuit. The strength of the series field is preferably so proportioned that it is smiicient to overcome the extra friction of rest.

To prevent magnet 131 becoming dei ncrgized when

contacts

129 and 130 open, and thereby separating

contacts

137 and 138. 1 use magnet 139 to keep the spool 131 cn'cr gized, as long as the motor armature is generating a moderate counter-electromotive force. The circuit for spool 139 can be traced from brush 98. through conductor 99,

contacts

100, 101, conductor 126, series field 102, conductor 141. conductor 140, spool 139, conductor 136 to brush 96. The switch 142 for spool 139 is closed as soon-asthe armature makes proper potential, and after 131, causing .will be seen that the separating of

contacts contacts

129 and 130 have energized spool it to close the switch 137, it

conductors 135 and 136, conductor 165 to armature brush'96. Themagnets 131 and 139 will only become denergized when the armature potential drops below a predetermined point.

I have shown in Fig. 4 a compound motor and while the compound field winding has advantages over the shunt field winding in hoisting motors, a motor with a shunt field winding may be used if desired as illustrated in Fig. 5. In this case the series winding 102 is omitted and a resistance 113 is placed in circuit with the shunt field winding 113. This resistance is short circuited by the contacts 138 which are arranged to be separated when the magnet 131 is energized. The circuit for the spool 139 may be traced from the brush 98 through conductor 99,

contacts

100, 101,

conductors

126, 140, spool 139, conductor 136 to brush 96. The magnet 139 closes the contacts 142 and maintains a holding circuit for the magnet coil 131 as before pointed out. The operation is substantially like that described in connection with Fig. 4. except that the mag net 131 when energized separates the contacts 138' to introduce the resistance 113 in the field circuit instead of the contacts being closed to short-circuit a series coil as in Fig. 4. In either case slowing down of the motor so' that the magnet 131 drops its core, eli'ects an increase in the strength of the motor field so that the torque is suflicient to enable the motor to follow up the movement of the gun.

In my Patent 379,387, above referred to, I have disclosed means for stopping the carrier automatically at difi'erent positions, varying with the position of the breech of the gun. The same device used there can of course be employed in this case in connection with controller F. Also, though I show controller F in the form of spirals, I do not limit myself to this construction. Any other suitable form, such as switches opened by cams, or equivalent construction, can be used. if desired.

It is understood that the position and length of the spirals and the location of the brushes is to be determined according t the travel of the car, and the movement provided for the spirals. The contacts and contact plate on the car switch also are to be located to suit the desired movement of the car switch handle. The spacing may be irregular. and the movement of the handle does not necessarily have to be to the center 'positionfor stopping. The position of the contacts is shown on the wiring diagram symmetrical, for clearness sake.

Slow speed can be produced by the operator at any time during the run by moving .the handle of switch S from extreme position toward the stop position, opening on the up motion the accelerating magnet contacts, while with such movement of. the switch S during the down motion, the contacts of magnet FS are closed. A stop can be made by the operator at any time by bringing the switch handle to stop position. for either up or down, thereby cutting 01? the power and applying the brake.

' I wish not to'be limited to the exact constructi'on disclosed, as various changes in the details of construction and arrangement of parts may be made without departing from the spirit and scope of the invention.

\Vhat I claim as new and desire to secure by Letters Patent in the United States is:

' 1, In an ammunition hoist, the comhination of a pivoted gun, a carrier, driving mechanism therefor, a stop device, a screwthreaded rod adjustably supporting the stop 'device, a motor connected to operate said rod, and powertransmitting means connecting the motor and gun to effect a movement of the gun upon its pivot.

2. In an ammunition hoist, the combination with a carrier, and driving mechanism therefor, of a gun, a stop device for the carrier separate from the gun, a screw-threaded rod supporting the stop device, a gear wheel carried by said .rod, a motor, and means comprising a power transmitting rod and gearing, for transmitting the power from the motor to the said screw-threaded rod.

3. Inan ammunition hoist, the combination with a in, of means for elevating and depressing t e muzzle of the gun, a carrier, means for raising the carrier, a stop device for the carrier, a. screw threaded rod suporting the stop device, a gear wheel carried by said rod, and a motor geared to said gun adjustingjmeans and said gear wheel to adjust the stop device to positions corresponding to the inclinations of the gun.

. 4. In an ammunition hoist, the combination with a gun, of means for adjusting the gun to different inclinations, a carrier,.

means for lifting the carrier, a stop, a screwthreaded rod supporting the stop, and means for automatically rotating said rodto change the position of said stop when the gun is adjusted to a different inclination.

5. In an ammunition hoist, the combination with a gun, of a carrier, driving mechanism for the carrier to elevate the carrier to positions opposite the gun, a stop for the carrier, and means for elevating or depressing the muzzle of the gun and said stop device, comprismg a motor, a gear driven by names riphery in mesh with the said first named gear, a jointed rod connected to the gun and having a threaded connection with said threaded portion of the cylinder, and a driving connection between said motor and said stop device. I

6. In hoisting mechanism, the yombination with a gun, of means for adjusting the gun to different elevations, a carrier, a motor for lifting the carrier to positions opposite the gun, a brake for the motor, manual means for controlling the application of the brake, and means for preventing the application of the brake while the carrier is opposite the gun.

T. In hoisting mechanism, the combination with a motor, of a car or carrier 1)ower-transmit-ting mechanism connecting the motor and car, a mechanical brake for the motor, a manual device for controlling the brake, and means for automatically preventing the application of the brake throughout a limited portion of the travel of the car.

8. In hoisting mechanism, the combination with a motor, aflcar, and driving connections therebetween, of an eleotro-magnetic brake for the motor, a manual switch controlling the circuit of the brake magnet, and an automatic controller operative to maintain the brake release for certain positions of the car independently of the man ual switch.

9. In hoisting mechanism, the combination with a gun, of means for adjusting the gun to difi'erent elevations, a carrier, a motor for lifting the carrier topositions oppo site the gun, a brake for the motor, manual means for controlling the application of the brake, and means controlled by the op* eration of the-carr'er motor for preventing the application of he brake while the carrier is opposite the. gun.

10. In hoisting mechanism, the combination with a gun, of means for adjusting the gun to different elevations, a carrier, a motor for lifting the carrier to positions oppo site the gun, an electro-magnetic brake for the motor, a. manual switch controlling the circuit of the brake magnet. an automatic controller, operative simultaneously with the carrier motor for maintaining the brake circuit for a limited time independently of the manual switch.

11. In hoisting mechanism. the combination with a car, of means for lifting the car, a stop to limit the upward movement of the car adjustable to different elevations in the path of car travel, locking mechanism operable to automatically lock the car to said stop, an elcctro-responsive device for releasing said locking mechanism and permitting the car to descend, and an electric switch controlling the operation of said car lifting means and electro-responsive device.

12. In hOIStIDg mechanism, the c0mbination With a car, of means for lifting the car,

an adjustable buffer in the path of the car for stopping the car when elevated, a catch operative to automatically lock the car to the buffer, an electro-magnet for releasing 10 the catch, and a switch controlling the operation of the electro-magnet and car lifting means.

In testimony whereof, I have slgned my name to this specification in the presence of two subscribing witnesses.

JOHN D. IHLDER.

Witnesses:

G. BVLI xx, G. J orn'.