42 _______________________________________________________________________________________________________________ THE COLLIERY GUARDIAN. January 7,. 1916. - trie Tool Company, of No. 394, Du Pont Building, Wilmington, Delaware, U.S.A.)—Delates to circuit control- ling means for electric hammers of a type adapted for use in chipping, caulking, riveting, cutting, and other work requir- ing a rapid succession of blows upon a suitable tool, and in particular relates to hammers having a plurality of oppositely wound coils, through which current is passed alternately to cause reciprocation of a magnetisable core, which is movable back and forth through the coils, and is adapted to deliver blows in rapid succession on a tool or tool holder. The inven- tion resides in the elimination of destructive sparking between the contact elements, whereby the circuit to the hammer is established, and then broken, and in the particular embodi- ment hereinafter described the arrangement is such that heavy currents may be established and then broken at relatively high frequency, and in a manner best adapted to ensure long life of the circuit controller, and best operation of the windings of the hammer. Pig. 1 is an elevation of the circuit controlling means with the commutator and brush-supporting drum, shown in section and one of the resistance boxes removed; fig. 2 is a side elevation of the commutator with the brushes removed and with a portion of the commutator broken away to expose the collector rings and one of the brush holders for said rings ; fig. 3 is a plan view of the brush carrier, showing the centrifugal governor used for regulating the pressure of the brushes on the commutator; fig. 4 is a transverse section through the brush carrier just outside of the slip rings; fig. 5 is -a plan view of the stationary commutator. The motor 1 is a direct-current motor, with its field frame 2 secured to a pedestal 3, mounted on a platform 4. Secured to the side of the motor field by screws 5 is a ring 6 carried on the arms 7 of a spider, through the central hub of which passes the arma- ture shaft 8 of the motor. This ring 6 is lined with insulating material, and is provided with a collar 9 fastened in place by screws 10; collar 9 has an inwardly projecting flange 11 fitting within the ring 6, and serving to anchor the collar firmly in place. The ring 6 and collar 9 are shaped, as shown in fig. 1, to grip a double series of commutator segments, and between these segments is an anchoring ring 12, bevelled on both sides, to lock in place the two series of commutator seg- ments. Mounted on the outer end of the motor shaft 8, and keyed thereto, is a hub 13, for driving the brush-supporting drum, the outer end of which is closed by a wall 14 made integral with said hub, and the inner end of which is open and encircles the body of motor 1. Openings 15 (fig. 2) through this drum are provided to receive brush-holding blocks 16 (fig. 3), which are fastened in place by screws 17, suitably insulated therefrom, as shown in fig. 4. These brush holders will each accommodate a plurality of brushes 18, say, four in number, and the brushes of each set. are yieldingly held against the commutator by a swinging block 19 mounted above the brush holder on a pivot pin 20, and carrying springs 21, which press yieldingly on the tops of the . brushes, to hold them to their work. Associated with each swinging block 19 is a projection 22, serving as a counterweight to increase the pressure on the brushes as the motor increases in speed, thereby increasing the friction between the brushes and the commu- tator, and preventing the motor from attaining a speed higher than would be suitable, for best operation of the electric hammer to be controlled. As a means for varying the effect of weight 22, there is provided an adjustable auxiliary weight 23, threaded to weight 22, and movable outward to magnify the centrifugal effect. A lock nut 24 serves to hold weight "23 in position after adjustment thereof. .The four brushes 18 of each group are connected together, and by flexible conductors 25 and 26 the two groups are connected respectively with slip rings 27 and 28 mounted on an insulating collar 29, which encircles hub 13, and is fastened thereto by a suitable set screw. The means, for establishing contact with slip rings 27 and 28 comprises a pair of diametrically opposite brushes, each carried by a spring, one of which is shown in elevation in fig. 2, where 30 is the brush held in a shallow pocket in the end of a yielding plate 31 operating as a spring support. The other end of this plate is fastened by screws 32 to an insulating block, which is anchored by screws '33 to one of. the horizontal arms of the commutator spider, as indicated in fig. 4. Plate 31 may be cut away between the brush socket and the supporting block, as indicated in fig. 2, and may be curved between the brush and the block to increase its resilience. The commutator is not of symmetrical construc- tion, but embodies a live segment 34 and a dead segment 35, and the latter may be supplemented by other dead segments 36 and 37. Interposed between the live segment 34 and the dead segment 35 are a series of auxiliary segments 341, 342, 343, etc., separated by intervening strips of insulation. This grouping of the segments is in duplicate. Deferring to fig. 5, it will be seen that the auxiliary segments, 341, 342, 343. etc., of the outer series are staggered with respect to the auxiliary segments 34% 34h, 34c, etc., of the inner series. This is for a purpose hereinafter explained. Except for the staggering of these auxiliary segments, the inner series of segments (fig. 5) operate in the same manner, and may be designated by the same numerals as the outer series. Mounted on platform 4 are a pair of boxes 38 and 39 (fig. 4) containing resistances of suitable design. These resistances are connected to the auxiliary segments of the commutator as indicated diagram- matically in fig. 6. The resistances are in a progressively increasing series, with the smallest resistance connected between the live segment 34 and its adjacent auxiliary seg- ment 34% and the next larger resistance connected between the auxiliary segments 34a and 341. In magnitude, these resistances are such that when a brush moves from live segment 34 toward dead segment 35, the current which might otherwise form a spark will be shunted through the resist- ance, and thereby diminished in value, but not immediately interrupted, and by continuing this progressive decrease in the current to the end of the series of auxiliary segments, the rotating brush can finally cross over to the dead segment 35, and break the circuit without sparking. In general, the resistances between adjacent segments are each made as large as possible, and still prevent sparking when the brush is operating under full load conditions. In addition to the auxi- liary segments 341, 342, etc., and their complementary seg- ments 34% 34b, etc., there are provided supplementary seg- ments 40 , 41, 42 , 43 , 44 , 45, and 46. These can be connected one by one to live segment 34, so that they will serve as extensions of that segment, and thereby increase the length of time during which current can be delivered to a brush as it rotates around the commutator. In general, the single live segment 34 is of such width, that when the motor is driving the brushes at a suitable speed, say, 1,750 revolutions per minute, the current taken from the live segment by The rotating brushes will be just sufficient to produce a light striking blow at the hammer. The impedance offered by the windings of the hammer’.to the periodic current flow with 6 Let, rV9 n 9 IS 1—. -4 /S I T S4 -4? -4? -43 F&4, which they are supplied holds back that current to such an extent that magnetic saturation of the solenoid plunger is not attained. By connecting to segment 34 one or more of the supplementary segments 40, 41, 42, etc., as by bridging the intervening insulation with solder, as indicated in fig. 4 at 47, 48, and 49, the effective width of the live segment 34 is increased, and the hammer will strike a proportionately harder blow. The possibility of thus increasing the effective width of segment 34 is particularly advantageous in adjusting for the particular voltage of the current to'be used in actuating the hammer, for, on voltages lower than standard, one or more supplementary segments may be soldered in to cause the hammer to strike its normal blow, even when working on the lower than normal voltage. In addition to the adjustments which may be made by soldering, there may be' provided a hand switch, with contact fingers, connected respectively with the supplementary segments 43 to 46, so that as the switch is swung around, these supplementary segments may be electric- ally connected as a part of the live segment 34, and so will serve to increase the duration of current flow to the hammer. (Six claims.) _____________________________ MEW PATENTS CONNECTED WITH THE COAL AND IRON TRADES. Applications for Patents. 18049. Electric fuses. V. Hope. 18051. Lancashire and Cornish boilers. W. M. Greaves and A. G. Brown. 18052. Well boring machines. J. Mellon. 18053. Variable countershaft belt pulley. A. T. J. Williams. 18072. Art of firing gas furnaces. J. Keith and G. Keith. 18090. Manufacture of steel. C. H. F. Bagley. 18104. Power transmission mechanism. A. O. Boyland. 18124. Feed motions for drilling .and boring machines. F. G. Thompson. 18156. Earth boring machines. 0. J. Williams. 18179. Safety device for inclined rope railways or similar railways. H. Proctor and E. Proctor. ■ 18185. Controllers for colliery tubs, tipping trucks, and the ■ the like. J. Neil. 18198. Signalling apparatus for use in connection with winding engines at collieries, mines, and other places. C. H. Bolton. 18209. Couplings for colliery trams and the like. H. Haddon. 18212. Improvements in signalling, also applicable for other purposes. C. C. Colley. Complete Specifications Accepted. (To be published on January 20.) 1914. 24837, 24838, and 24839. Alternating-current dynamo- electric machines adapted for synchronous work- ing. Hunt, and Sandycroft Limited. 1915. 85. Apparatus for discharging coke hoppers or the like. Duckham. 491. Systems of electric motor control and controllers there- for. British Thomson-Houston Company. (General Electric Company.) 1678. Clamping devices for securing together wires, ropes, rods, or the like. Bullivant and Selby. 4730. Hammer rock drills. Kimber. 4948. Deverberatory furnaces and the like. Payne, Smith, Smith, Smith, Smith, and Smith. 5509. Becording devices for use in connection with the . stoking of boiler furnaces. Kerr. 6506. Valve gear for direct-acting pumps. Bose. 6732. Begulating and safety apparatus for boiler feed pumps. Geb. Stork und Co. 877L Oscillating fans. Komatsu. 8886. Process for the production of toluene. Sifton and Harding Brothers (Engineers, Westminster) Limited. 9437. Apparatus for the production of toluene. Sifton. 10520. Elevators. Suisted’s Patent Coal Elevator Limited, and Dobinson. 11380. Valve gear for pneumatic tools. Christiansen. 12570. Process and apparatus for distilling heavy crude petroleum. Tudor. (Venturino.) ____________________________ GOVERNMENT PUBLICATIONS. s Any of the following publication® may be obtained on application at this office at the price named post free. MINES AND QUABDIES : General Deport, with Statistics re Output for 1914, 3Jd.; Form 23, lid. Ministry of Munitions : Deturn of Cases Heard before Munition Tribunals, lid. Statutory Bules and Orders, 1915 : No. 1183, Customs, Order in Council, l|d. Acts, 1915 : Trading with the Enemy (Extension of Powers), Id. Inland Bevenue Commissioners’ Beport for 1914-15, Is. 8d. Local Government Board Circular on the Beduction of Work, December 17, 1915, ljd. East India : Beport on the Work of the Indian Students’ Department, July 1914 to June 1915, 2Jd. __________________________ PUBLICATIONS RECEIVED. Business Prospects Year Book, 1916. Edited by J. Davies and C. P. Hailey. Cardiff : Business Statistics Company Limited. Price, 10s. net. “ Electrothermic Smelting of Iron Ores in Sweden,” by Alfred Stansfield (Mines Branch of the Canadian Depart- ment of Mines); ‘ ‘ Bulletin et Comptes Bendus Mensuels de la Societe de 1’Industrie Minerale ” (Tome 8), July- September; “ Trade of the Union of South Africa, Southern and Northern Bhodesia, and British South Africa for October,” price 3s.. 6d.; “ Journal of the Boyal Society of Arts” (No. 3293, Vol. 64), December, price 6d.; “The Naturalist” (No. 708), January; “The Journal of the Society of Architects ” (Vol. 9, No. 99), January; “ The I.C.S. Student ” (Vol. 8, No. 1), January; “ Anglo-Nor- wegian Trade Journal ” (Vol. 1, No. 12), December ; “ Proceedings of the Engineering Association of New South Wales, 1913-14 ” (Vol. 29); “ The Chamber of Commerce Journal ” (Vol. 35, No. 261), January, including supple- ment, ‘ ‘ Annual Trade Beview, 1915, ” price Is. _____________________________ Grimsby Coal Exports.—There has been no export of coal from Grimsby during the week ended December 31, 1915. During the corresponding period of 1914 the totals were : Foreign, 4,635 tons; coastwise nil. Almanacs and Calendars for 1916.—Messrs. James Light and Son, Liverpool, importers, refiners, and blenders of oil, send us their calendar for the new year, and .also include a copy of their booklet describing their specialities. From the Davenport Engineering Company, of Bradford, we have received a calendar of the daily block type; this firm are manufacturers' of the Holehouse patent water cooler. Messrs., the “ Perfects ” Boiler Circulator Limited and Messrs, the United States Metallic Packing Company Limited have for- warded their calendars, which are of the monthly tear-off sheet type. Messrs. Simon-Garvesi Limited, of Manchester, send us their daily block calendar, each day’s sheet of which contains well-known and happily-chosen axioms. Hull Coal Exports.—The official return of the exports of coal from Hull to foreign countries for the week ending Tuesday, December 28, 1915, is as follows :—Amsterdam, 600 tons; Dunkirk, 1,691; Gothenburg, 2,448; Harlingen, 523; Halmstadt, 743; .Botterdam, 640; Bonen, 18,798; Treport, 1,218—total, 26,661 tons. The above figures do not include bunker coal, shipments for the British Admiralty, or the Allies’ Governments. Corresponding period, December 1914, total 40,784 tons; corresponding period, December 1913, total 80,820 tons. __________________________________________________________________________________________________________________________ Siemens Open Hearth. ________________________________________ First-class Medals— Paris, 1885; London, 1862. “SHELTON” IRON “SHELTON” STEEL Gold Medals— Paris, 1878 ; Melbourne, 1881. REflSER OVER 1,400 PAIRS SOLD. E-W NEWPAtENT N020901.1913, fcWi.' hw/zt zz?/? mws. ro sole man ufk AUTOMATIC I EVANS Er DODD k I CANNOCK. “GRANVILLE” PIG IRON <=> STEEL PIT GIRDERS & COLLIERY RAILS a Speciality; also High-class RAR IRON for Couplings, &c. IRON & STEEL BARS, ANGLES, TEES, CHANNELS, GIRDERS, PLATES & SHEETS, STEEL BILLETS, BLOOMS & SLABS. The Gosforth Foundry Co. Ltd. Malleable Ironfouiiders, DRONFIELD, near SHEFFIELD. Enquiries to— . _______ THE SHELTON IRON, STEEL & COAL CO. LTD, Or 122, Cannon Street, London, E.C. Wegraphic AddressShelton, Stoke-on-Trent.” Tel. No. 11 and 253. | Telegraphic Address : Sheltonian, London.” Tel. No. 886 Bank. _______________ Makers of all kinds of DRIVING & ELEVATOR CHAINS, SPROCKET WHEELS, ELEVATOR BUCKETS, &c.