US1262916A

US1262916A - Controlling device for self-focusing electrical-arc lamps.

Info

Publication number: US1262916A
Application number: US8790416A
Authority: US
Inventors: John L Boyle
Original assignee: Individual
Current assignee: Individual
Priority date: 1916-03-31
Filing date: 1916-03-31
Publication date: 1918-04-16
Anticipated expiration: 1935-04-16

Description

J. L. BOYLE.

'CONTROLLING DEVICE FOR SELF FOCUSING ELECTRIC ARC LAMPS.

APPLICATION FILED MAR. 31. 1916.

1,262,91 6. Patented Apr. 16, 1918.

3 SHEETS-SHEET 1.

@f A f 9 07- Mia? J. L. BOYLE.

CONTEOLLING DEVICE FOR SELF FOCUSING ELECTRIC ABC LAMPS.

`APPLICATION FILED MAR. 31.1916.

Patented Apr. 16, 1918.

3 SHEETS-SHEET 2.

L L. BOYLE.

CONTROLLING DEVICE FOR SELF FOCUSING ELECTRIC ARC LAMPS.

. APPLICATION FILED MAR. 31, 19H5. 1 ,262,91 6. Patented Apr. 16, 1918.

3 SHEETS-SHEET 3.

fili/eminr 'NTD STA PATNT OFFCE,

JQHN L. BQYLE, ,0F BOSTON, ]LSLISSACHUSETTS,-

CONTB'OLIJNG DEVICE FOR- SELF-FOCUSlNG ELEGTRC-ABC @Ml/@S Substitute .for applioetion` Serial No. eil, filed Januar-y 13, 1913'.

Specification of Letters Patent.

,Patented Apr. 16, 1.918.-

This application ledMarch 31, 1916.-

SerialNp. 87,904.

T his invention nelates to controlling :dee

vices for electric are lamps end is a substitute for application, Seri-al. #7411672., filed January 13, 19,13.

The -ohjeot of. the intention is to provide eontrollingfnieansfor electrie ,are lenip whereby the are shall be automatically main.- tained et e predetermined point, euch .for example as `the optical :Center .of o .lenswith which thelamp ie employed- Alfthough the invention isV yshown eonneetion with what is commonly termed va focusing arc lainp it will be understood that it is also adapted for use with a non-focusing are lamp,

One forni of the invention contemplates the provision of eleotrorresponsive means controlled by the ,current passi-n0r from one to the other electrode for lowering or rais.- ihg the are eooordng as, lthe, .Center of the same. moves lup or down with respect to a predetermined point, eaused by` the koonsumption of theeleetrodes. In earn-ying outthis form of the invention aV contact-member is provided., which is adri-rated` tor malte contact with one `or .the other or both of the electrodes adjacent `the are, and this oontaoi member is oorninon to two y circuits, eaoh .oi-r.- ouit containing an ,electro-responsive device arranged to control actuating-means by which the lamp is raised and lowered, and the ero maintained et e phedetermihed point, one of said circuits being ooroieeted to the upper electrode and the Vother circuit being connected to the lower electrode.

The heet of the ordinary are ie lvery ntenee, ySo that it preierohle to. more the @ontw-member intermtt tlv into end ont of .Contact therewith or with the electrodes et Short intervalsbnt es Said @omelet-memeher heey: rem-ein o oofinnonely in oonteot with the are., etleeet. fore Short period .1o.f`vtme., I.

have, therefore Freeride@ .ineens for emotie ing innemen, feuitehle. ,both oi these oomtions A further feature. of the ilwention .oon-

teniplates the provision of a posi/tive stop which is arranged to be inserted periodically between the electrodes, and then the electrodes are brought into engagement therewith to relocate the are.

l will describe Iny invention in the ollowing spekoifieation, and willr lpoli-nt out the novel features thereof the appended claims,

In the accompanying drawings,

Figure 1 is a diagrammatic view illus tre-.ting one embodiment of vthe invention, suitable for use with an ordinaryaa-re.

Fig. 2 is a plan view of the mechanism for raising and lowering the are.

F ig.3 is a side elevation of the mechanism shown in F ig.v 2.

Fig. 4- is a Vplan view .of the mechanism for controllng the circuits of the raising and lowering mechanism.

Fig. 5 is a side elevation of the same.

Fig. 6 is aside elevation of the mechanism for actuating the .oontaot which engages the electrodes Figs. 7, 8 and 9 are details ofi the mecha;

nisrn for periodically closing the circuit` which eothotee the .Contact FLI- 10 :is a diagrammatic -rfiew ior 1e modified form of the i,evention- Fig. 1l is a diagrarnrnalti ViewV Qi an. other modified form of the invention.

Fig. 112 is a diagrarnrnatie view of still another ined-ined forni rof the invention.

As illustrated in Figs. 1 .to 9, inelusiive, 10 represents housing for an electric are amp, Whioh mer be o f the Well-known focusing type, having an upper electrode 1 2 and a lower electrode 1 4. The lamp is designed to be arranged upon any suitable adiueteble .Support or table 1.6.` so that vthe position .of the are 18, formed between the electrodes 12 and 1 4. may be vertically ad: justed as -desi-red `with respect `to -a predef. terroineel poiliit-y euch jthe, ootoel center? of e 1ere, 01- the like The oleetrodes preereblv entre .long endmenne mov berno: vided Yfor keeping them in perfeot Ye1inerme.1n-

Arreneed So to engage. .ei-ther or both ofthe eleotroflee 12. ie Ya,.comoet--nlelnloer 20, which may be of carbon or other suitable ytaining an electro-responsive device.

to be moved periodically into and out of engaging position by mechanism which will be hereinafter described. lVhen the arc is in its correct position and the contact-memloer is moved into engaging position it may engage the are only, but when the arc has shifted to a position above or .below the predetermined point, due to the consumption of the electrodes, said contact-member will engage one or the other oi said electrodes according to which direction the arc has shifted.

The upper electrode 12 is connected by a wire 22 to coil 23 of an electro-responsive device, such as a relay-switch, and said coil is connected by

wires

24, 25, to the contactmember 20. The lower electrode 111 is connected by a wire 2S to coil 30, of an electroresponsive device, such as a relay-switch, and said coil is connected by a wire 31 to the wire 25, which leads to the contactmember 20. Thus there are two circuits having a common conductor connected to the contact-member 20, each circuit con- Said devices or relay-switches are adapted to control mechanism for moving the lamp bodily up or down as required.

The mechanism here shown for raising and lowering the lamp comprises a pair of electro-magnet coils 32, 34, arranged in a suitable housing 35 which contains the sup- Jort or table 16. The coil 32 is connected by a wire 36 to a stationary contact-member A87, and is connected by

wires

88 and 39 to a supply-wire 10. The coil 31 is connected by a. wire 42 to the wire 39, and is connected by a wire 44: to a stationary contact-meinber 45. A stationary contact-member 46, adjacent the contact-member is connected'to the supply-wire 4S, and a stationary contact-member '19, adjacent the contactmember 39 is connected by a wire 50 to the said supply-wire 4S. The contact-

members

45 and 46 are adapted to be bridged by a switch-arm 52 carried by an armature 53 for the coil 23, and the contact-

members

37 and 49 are adapted t0 be bridged by a switch-arm 5% carried by an armature 55 :tor the coil 30.

The electro-

magnets

32, 31, are preferably solenoids having slidable iron cores or

plungers

60, 61, respectively, arranged to pass through guides 62. |The inner end of each core is connected to the correspond ing end of a brass or other non-magnetic rod 64, slidable through a guide 66, and provided at its outer end with a cross-bar 68. The ends of each cross-bar are connected to

retractile springs

69, 70, which are attached to adjusting-screws 72, 7 3, by means of which the tension of said springs is adjusted.

-A lpawl 74 is pivotally connected to the outer end of the core and is held in yielding engagement with a ratchet-wheel 7 6, by a spring 77; and a pawl 7S is pivotally connected to the outer end of the core 61 and held in engagement with a ratchet-wheel 80 by a spring 81. The pawls 71 and 'TS are normally out of engagement with the ratchet-wheels 76 and 80, respectively, but are brought into engagement therewith by the movement of the

cores

60 and 61, respectively, when their respective coils 32 and 31- are energized. The ratchet-wheels 76 and 80 are 'tast on a vertical shait 82 journaled in a supporting-base 81, and provided at its upper end with a screw-threaded portion 86 which engages a nut 8T supported by brackets S8 depending from the under side of the table 16. A pair of sockets 90 are secured to the under side of the table 16 and receive guide-rods 91 which project upward from the base 81:. lVlien the coil is energized its core 60 is drawn in and the ratchet-wheel 7 6 is rotated clockwise thus turning` the screw 86 to raise the table 16, the cross-bar 63 is moved outward and the

springs

69 and 70 are put under tension. When the coil 32 is denergized the core 60 and connected parts are returned to normal position, as shown in Fig. 2. lVhen the coil Sil is energized the core 61 is drawn in and the ratchetswheel S0 is rotated counter-clockwise, thus turning the screw 86 to lower the table 16. By thus raising or lowering the table 16 the are 18 is raised or lowered with respect to the predetermined or focus point.

The electro-responsive devices for controlling the operation of the raising and lowering mechanism are shown diagrammatically in Fig. 1, but they may be constructed asA shown in Figs. 41 and As here shown, the

coils

23 and 30 are solenoids having slidable iron cores or

plungers

100, 101, passing through guides 102, 103, and connected at their outer ends to

springs

104, 105. The inner ends of the

cores

100, 101, are connected to

non-magnetic rods

108, 109, passing through

guides

110, 111, and provided at their outer ends with

casings

112, 114. Each casing houses a spring 115 which engages the opposing end of one of the rods 10S, 109, and said springs also engage the inner ends of

rods

116, 117, slidable in said casings.

rlhe rods

116, 117 are provided with Contact blocks 11S, 120, suitably insulated therefrom and adapted to bridge the

stationary contacts

45, 116 and 37, 19, re snectively. In this c.,;istruction the contact blocks 118 and 120 are yicldingly supported and are adapted to adjust themselves to malte a firm engagement with the stationarv contacts when the coils are energized. y

lVhen the

coils

23 and 30 are energized their cores 100 and. 101'are drawn in and the

springs

104 and 105 are put under tension. In order to prevent a too rapid movement of the cores and connectedr parts when returning to normal position, a retardingdevice or escapexnent is provided for each Core. It comprises a shaft 125 journaled in bearings 126 and provided with blades or vanes128. A ratchet-vvheel 130 is ailixed to the shaft 125 and is adapted to be engaged by a paivl 132 carried by the core of the solenoid. When the .core is drawn back by its spring. 104, or 105, the teeth of the pawl engage the corresponding ratchetsvheel to rotate the shaft 125, and the comparatively large surfaces of the vanes 128 produce a retarding action on said shaft.

The contact-member 2O is mounted upon a holder 140 which is yieldingly and slidably connected to a rod 141 passing through a guide 142. The inner end of the rod 141 is connected to the inner end of a magneticcore 144 which is slidable Within a solenoid coil 146, and is connected at its outer end to a spring 148.

The coil 146 is periodically energized to bringl the contact-member 20 into engage` nient with one or the ,other of the electrodes 12, 14. To accomplish this a continuously ruiming motor is provided, which may be of any Well-known r suitable construction, although an electric-motor 150 is here shown, having its armature connected to

Wires

151 and 152, leading to the supply-wires- The motor is provided with a shaft 154 having a Worm 155, which engages a Wor-m-wheel 1.56 on a shaft 1.57, and the llatter is provided with a Worm 158, Ywhich engages a Worm Wheel '159 on a shaft 160. Aliixed to the shaft .160. is a drum 162, made of insulating material, preferably Wood.. Mounted on the periphery of the drum 162 is a contact-plate 164 havingv an overhanging upper edge .and this plate is covered over a considerable portion of its area by an insulating plate 166, also having its upper edge overhangin. A pair of springv contact-

arms

116,8, 169 are adapted to :engage the periphery o1"- the drum 162 and to Vslide up over the

plates

166 and 164. As the

arms

168, 169 move past the upper edge of the insulating plate 166 they are snapped quickly against the contact-plate 164, see Figs. 8 and 9, to make a good contact therewith and establish the circuit, and then as they move past the upper edge of the plate 164 they are snapped quickly against the periphery ot the drum to break the circuit. The arm 168 is connected by a Wire 1Z0 to one end of the coil 146, the other end of Asaid coil being connected by a Wire 172 to the return-wire 48, of' the supplyy circuit, and thek arm 169 is connected by a wire 174 to the 'supplywvire 'The drivingmechanism for the drum- 162 is preferably so Atimed that-the lcircuit through the coil 146 is momentarily closed every three minutes or thereabouts.

The operation of this form of the invention is as follows Normally the current passes from the electrode 12 across the arc 18 to the electrode 14, said electrodes being connected in circuit in a well-known manner. The current divides in the .electrode 12, some passingthrough the wire 22, .Coil 23, Wires 24, 3.1 coil 30 and Wire 28 to the electrode 14. 1t will be noted that the coils and 8O are in series, and they are so constructed that comparatively little current passes through them, not enough to attract their armatures.

l/V hen the plate 164 closes the circuit through the coil 146, said coil is energized and moves the contact-member into engaging position. Tf the center of 'they arc 18 is in its correct position the contact 20 will engage both electrodes and there will be no eect on the coils and to move their armatures. Suppose, however, that the arc is below the required point, then the contact-member 2O Will engage the upper elec trode 12 and thus short-circuit the coil This enables a larger portion or' the currentto pass through the coil 8O to energize it sutlliciently to attract its armature and bridge the contact-members 37 and This closes the circuit through the coil 32, Which thus becomes energized and drawn in its core 60. The pand 74 engages the ratchet-Wheel 76 and impart-s a partial rotation to said ratchet-Wheel and to the screw 86 to raise the table 16 and with it the lamp. The circuit through the coil 146 is then broken when the

arms

168 and 169 leave the plate 164, and the spring 148 retracts the contact-nehmer 26, Tr the arc is too high when the contact-member 20 is moved into engaging position the latter engages the lower electrode 14 and the coil 30 is short circuited. This allows the coil v28 to be energized sufficiently to attract its armature 53 and bridge the contact-meinbers aid 46, thereby closing` the circuit through the coil 34 which operates the mechanism in the housing so to lower the lamp and are.

Contact 2() is adapted to be periodically moved into contact With the arc or its electrodes at some predetermined rate, say about once in three minutes. il" it touches one .of the electrodes the lamp is adjusted away from the contact until equal current flows in both relays, and then the lamp control ceases to act. The arc can new be displaced from the predetermined `lined point at which contact `2O is located by an amount equal to the difference in unequal carbon consumption during the period between adjustments. This Shifting of the arc is, in practice, so smallE as not t0 affect the practical operation of the apparatus.

1n Fig. 10 I have shown a modified form of apparatus, in which the contact-member which engages the arc is lrept in continuous Contact therewith.

As here shown 200 represents a housing for the are lamp having an upper electrode 202 and a lower electrode 20-1, said lamp being mounted on an adjustable table or support 16, as explained above, and said electrodes being connected in circuit in any well-known manner.

A xed contact-member 206 is mounted in a holder 207 which projects later lly from a stationary support 208 suitably secured in place, and this contact-member is adapted to engage the arc 209, the engaging end of said contact-member being located at the center of resistance the arc, when the mathematical center of the arc is in line with the optical center of the lens.

The upper electrode 202 is connected by a wire 210 to one end ot' a coil 211 oit' an electromagnet, and the other end of said coil is connected by wires 212 and 214C to the contact-holder 207 which is connected te the contact-member 206. The lower electrode 2041 is connected by a wire 216 to one end or a coil 217, and the other end oi this coil is connected by a wire 218 with the wire 2141.A

Thus there are two circuits having a common conductor 2111 connected to the contactmember 20G, each circuit having an electroinagnet adapted to control the mechanism lor moving the electrodes of the lamp in substantially the same manner as explained in the foregoing.

The mechanism for raising and lowering the lamp comprises a pair of electromagnet coils 32 and 34 arranged in a suitabl housing 35 and connected with mechanism which raises and lowers the table 16, as heretofore explained.

One end of the coil 32 is connected by a wire 220 with a stationary contact-member 221, and the other end of this coil is connected by

wires

222 and 223 to a supplywire 224-. One end of the coil is con- Y nected by a wire 226 with a stationary contact-member 228, and the ot1 er end et the coil is connected by a wire 229 to the wire.

223. A pair of stationary contact-ineinbers 230 and 231 are connected by wires and 235, respectively, to the supply-wire A double-throw switch blade is mounted on an arm 238 fulcrumed at 239 and provided with an armature 2e/10 for the electromagnets 211 and 217. The operation of this form of the invention is as follows Normally the greater portion of the current passes from the electrode 202 across the arc 209 to the electrode 204C, said electrodes being connected in circuit in ar well-known manner, and a small portion of the current passes through the wire 210, coil 211,

wires

212, 214, holder 207, contact-member 206 to electrode 20-1, and also wire 218, coil 217, and wire 210 to electrode 201. The current in the coils 211 and 217 is balanced so that the arm 238 remains in a central position when the center oi the arc coincides with the conta t-member 20G.

Suppose, however, that the arc center is below the center olf the contact-member 206, then the portion ot the arc extending between the contact-member 20G and the upper electrode 202 is shorter than the portion of the are extending between the contact-member 200 and the lower electrode 201. Consequently, the resistance oil that portion ot' the arc between the electrode 202 and the contact-member 200 is less than that between the contactcneniber 200 and the el cctrode 204. A larger current will therefore flow from the electrode 202 through the contact-member 200, holder 207, wires 2111, 218, coil 217 and wire 210 to electrode 204. The coil 217 thus becomes energized suf iiciently to attract the armature 210 and move the switch-contact 230 to bridge the stationary contact-

members

221 and 231, thereby closing the circuit through the coil which actua-.tes the mechanism for lifting the lamp. 1f the arc center should be above the predetermined point, the current would energize the coil 211 sul'licicntly to attract armature 2&0 and close the circuit lnrough the coil 31 which actuates the lowing mechanisi'n. 1n Fig. 11 I have shown an auxiliary souixe'o current such as a storage battery 40, which is connected by a wire 341 to the jper electrode 12, and by a wire 342 to a coil 3414- ot' arelay-switch, said coil being connected by a wire 346 to a contact 348. The coil 344 is provided with an armature 350 on a switch-arm 352 which is adapted to bridge contacli-members 35i, 355 connected in a controlling-circuit as explained above. 1n this ligure circuit connections are shown for one electrode only, for simplicity, but, in practice, the controllingr circuit connected between electrode 14E and contact 3118 con- 'tains a regulating relay with its operating attery in all respects similar to the relay 344i and battery 340, as shown. The operation of this form of the invention is substantially as heretofore described. Then the arc becomes displaced and contact 348 comes into contact with say electrode 12, current from battery 340 flows between electrode 12, contact 348 and connecting wires to regulating relay 344, which energizes apparatus previously described to restore the are to its normal position. Vhen the are becomes displaced in the opposite direction, and contact comes into engagement with electrode 14, current flows through theother regulating circuit with its battery corretua-aaai@ spending to battery 340 and regulating relay corespondin to relay 344, and which circuit is not shown in the drawing, to adjust the arc to its normal position. ln this iorm of the invention the arc current is not utilized to operate the regulating relays, but a separate source oi' current, viz, batteries 340, are utilized for this purpose.

1n Fig. 12 l have shown another modiiied form ot' the invention, which comprises a housingV 400 for the arc lamp having an upper electrodee402 anda lower electrode 404, said lampbeingmounted on an adjustable support 406, vas explained above, and said electrodes being connected in circuit in any well-known manner.

f Theelectrodes

402, 404 are connected by a shunt, composed oi two branches 407, 40S having

balanced resistances

410, 411 connected therein. A lined contact-member 412 is mounted in a suitable holder and is adapted to engage the electrodes when the arc has moved from its correct position, as eX- plained above. The contact-member 412 is connected by a wire 414 to the armature of a reversing-motor 416, said armature being also connected by a wire 418 to the junction of the branches 407, 408 of the shunt.

The motor 416 is provided with a shaft 420 having a worm 421 which meshes with a worm-wheel 422 on a vertical shaft 424, said shaft being screw-threaded at its upper end to cooperate with a correspondingly threaded bracket 426 secured to the adjustable support 406.

r1`he operation of this form of 'the invention is as follows l/Vhen the arc is in its correct position, a portion orn the current iiows through shunt, but not. sufficient to operate the motor 416. 1f the are is raised above the predetermined point, the lower electrode 404 will engage the contact-member 412, and the resistance 411 will be short-circuited. Thereupon an increased current will flow through the shunt-branch 40?1 having the resistance 410, wire 418, armature of motor 416, wire 414, and contact-member 412 to the electrode 404, and the motor 416 will be driven in the direction to cause the screw 424 to lower the support 406, and with it the lamp 400. 1f the arc becomes lowered below the predetermined point or optical center, the upper electrode 402 will engage the contact-member 412, and the resistance 410 will be shortcircuited. Thereupon an increased current will flow through the shunt-branch 406 having the resistance 411. This current will How from the electrode 402 through the contact-member 412, wire 414, armature of motor 416, wire 418 and branch 408 to electrode 404, said current being in the opposite direction from that just set i'orth above, and consequently the motor is driven in the opposite direction to raise the lamp'. The motor 416 maybe employed as an actuatingmeans `when controlled by the other forms or' controlling-means, which are shown in the other iigures as well as when controlled by the means shown in TEig. 12.

will be understood that, the electrodes in all the various forms of the invention may, it desired, be inclosed from the atmosphere, thus increasing their life.

1 claim:

1. Tie combination with the electricV are lamp having electrodes, of means for varying the position of said are lamp, and means adaited to be brought into contact with the electrodes thereof at a predetermined arc for i' ment of said are lamp, substantially as decribed.

2. rlhe combination with an electric arc lamp having a pair of electrodes, of means of adjusting sL idk electrodes, and means adap ted to be brought into electrical contact with the electrodes at a predetermined arc forming place to determine said arc forming place, substantially a described.

3. rlhe combination with an electric arc lamp, of means for varying the position of the lamp to correspondingly vary the position of the are, with respect to a predetermined tired point, and means adapted to be brought into Contact with the are for controlling the direction of movement of said lamp, ubstantially as described.

4. an electric rc lamp including a table, a screw 'for raising and lowering the table, a pair ot' electrodes mounted on the table, a pair or" electromagnets, means operated by said magnets for turning said screw in opposite directions to adjust the elevation of the table, to correspondingly adjust the position or" the are between the electrodes with respect to a lined point, and means affected by a change in the position of the arc to control the direction of movement of said table.

5. The combination with an electric arc lamp, of means for varying the position of the lamp, a pair of normally inoperative electro-responsive devices, controlling actuation of said means, and means -for shortcircuiting one of said devices when the center of the are has moved away from a predetermined point, substantially as described.

6. rEhe combination with an electric arc lamp, of means for varying the position of the lamp, a pair of normally inoperative electro-responsive devices controlling actuation of said means, and arranged to be operated by a portion of the current passing through the lamp, and means for short-circniting one of said devices when the center of the are has moved beyond a predetermined point, whereby the other of said deng jlace for controlling the movevices is actuated to operate the arc-varying means, substantially as described.

7. The combination with an electric are lamp, comprising a pair of electrodes, of electro-responsive means for raising and lowering the lamp, a contact-member arranged to engage said electrodes, and means connected to said contact-member arranged to control the operation of said raising and lowering means, substantially as described.

8. The combination with an electric arc lamp, comprising a pair of electrodes, of electro-responsive means for raising and lowering the lamp, a contact-member, means for periodically moving said contact member into and out 0f the arc space, and means connected to said contact-member for controlling the operation of said raising and lowering means, substantially as described.

9. The combination with an electric arc lamp, comprising a pair of electrodes, of a contact-member adapted to be brought into engagement with said electrodes, means for intermittentlymovingsaid contact-member into engaging position, and means for raising and lowering said lamp according as the center of the arc is below or above a predetermined point, substantially as described.

10. The combination with an electric arc lamp, comprising a pair of electrodes, of

means for centering the arc, a contact-member adapted to electrically engage the are at a predeterlnined point, a pair of opposed electro-responsive devices arranged to control the operation of said centering means, said means being inactive when the center of the arc is at said predetermined point but adapted to be actuated by an unbalancing of the current flowing through said devices due to the movement of the center of the arc away from said predetermined point, substantially as described.

11. A self-focusing electric arc lamp, comprising means for varying the height or" the arc, a. motor, a contact-device actuated by said motor, a circuit arranged to be momentarily closed by said contact-device, means controlled by said circuit for engaging the electrodes of said lamp, and means controlled by the current ot' the arc circuit for actuating the means for varying the height thereof when its center has been moved away from a predetermined point by an unequal consumption of the electrodes, substantially as described.

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

JOHN L. BOYLE.

Witnesses H. B. DAVIS, B. J. NoYEs.

Copies o! this patent may be obtained for ve cents each, by addressing the Commissioner of Patenti.

Washington, D. C.