384 THE COLLIER r GUARDIAN. August 14, 1914. to the same bracket), in such a manner as to allow both the door and the strut to turn freely together on their respective fulcra or axes for opening and closing purposes without jamming or locking, and an independent fastening or locking device operatively mounted upon the strut between its ends, is also provided for holding the said strut and with it the door in the upright or closed position. The fulcrum of the strut is at some distance below the fulcrum of the hinge, and may be in the same vertical plane as or in front of the hinge fulcrum. The strut may be rigid or made in parts jointed together, and the fastening or locking device is adapted, when rotated or otherwise moved, to engage with and to be disengaged from a hook or projection on the bracket aforesaid to which the hinge is also preferably connected for the purpose of locking the strut, and with it the hinge and door in position, or for unlocking the same, according to the direction of movement imparted to the said fastening. The said hook is suitably formed in one with the fixed part of the hinge, and the door hinge is slotted or fork-shaped in the vicinity of its pivot to allow the hook to project through same, and so that the hinge may turn without coming into contact with the said hook, while, if necessary, the strut is also slotted to allow it to pass over the hook. The locking device, which is suitably made in the form of a cam operated by a lever, is so constructed as to automatically effect the locking of the strut and door when the latter is raised to the closed position. Fig. 1 is a vertical transverse section on the line 1—1 fig. 2 of part of a railway wagon or freight car with a hinged or fall- down door provided with a hinge and strut made according to the invention; fig. 2 is a side elevation; fig. 3 is a cross- section of the hinge on the line III—III, fig. 2; fig. 4 is an enlarged view of parts of the locking or retaining device seen in fig. 1; fig. 5 is a front view of fig. 4, and an enlarged view of parts seen in fig. 2. (Eight claims.) 16125 (1913). Improvements in and relating to Rock Drills and Detachable Bits or Cutters therefor. R. Jones, of 308, Fox-street, Fairview, near Johannesburg, province of Transvaal, Union of South Africa.—Appertains to that type of rock drill in which a detachable bit or cutter is provided with a tang formed integrally therewith or other- wise permanently attached thereto, whilst the holder therefor is provided with a tapered axial recess and radial cotter holes or drift ways formed so as to intersect the axial recess. According to the invention, the holder of the drill is rendered sufficiently resilient to grip the tang of the bit or cutter by fashioning it with an axial recess and forming in one side of the holder a longitudinal saw-cut or slit, which communicates with the said axial recess. After the saw-cut or slit has been formed in the side of the holder, the holder is then squeezed inwardly from two opposite sides at right angles to the saw-cut or slit. This imparts to the recess in the holder a slightly elliptical shape nS 6 re- 2- 3— // IO —3 ___A> -IS -3 If in cross-section. When driving the tang of the bit or cutter into the elliptical tapered hole or recess in the holder, it expands the latter by opening the saw-cut or slit, with the result that the natural resilience of the holder causes the tang to be firmly gripped by and retained in the holder. If found requisite or desirable, an improved safety locking device may be employed to prevent the bit or cutter being detached from the holder when the drill is in use. An improved removable head or sleeve member of known type may be provided for receiving and gripping the tang of the detachable bit or cutter, and said removable head or sleeve be secured in the holder. Fig. 1 is an elevation of one form of the invention; fig. 2 is a sectional plan of fig. 1 on line ®—x; fig. 7 is a view similar to fig. 1, illustrating the provision of the safety locking device; fig. 8 is a longitudinal section at right angles to fig. 7; fig. 9 is a part-sectional elevation, illustrating the use of the removable head or sleeve. (Seven claims.) NEW PATENTS CONNECTED WITH THE COAL AND IRON TRADES. Applications for Patents. 18280. Apparatus for detecting the presence of firedamp and other gases in connection with the use of the electric lamp or battery. W. Gaudie and G. Wilkinson. 18314. Signalling apparatus such as is employed in collieries and the like. John Davis and Son (Derby) Limited, and F. F. MacDonald. 18333. Manufacture of explosives. H. Wade. (Spreng- stoff Akt.-Ges. Carbonit, Germany.) 18381. Gas producers, blastfurnaces, or the like. T. Bairdow. 18387. Process of heat treatment of steel. E. C. R. Marks. (Soc. Anon. Italiana Gio. Ansaldo & Co., Italy.) 18390. Discharging device for vertical retorts. P. Plan- tinga. 18397. Percussion tools. Siemens-Schuckertwerke G.m.b.H. 18404. Coal and rock boring machines. A. Berner. 18406. Apparatus for generating oxygen or other gases. P. A. Smithurst. 18426. Means for preventing the drop of lifts or cages when the hauling rope breaks. L. D. Mantell. 18437. Furnaces for the destructive distillation of carbona- ceous substances. W. W. Crawford. 18442. Electro-magnetic unlocking and unscrewing appar- atus for miners’ lamps. O. Oldham. 18449. Cable haulage clips. A. E. Stroud. 18457. Machines for cleaning, separating, and screening stone, ore, coal, and the like. L. Lister-Kaye and C. E. Blyth. 18460. Method of and mechanical combination and con- tinuous furnace for removing covered coating and detinning old tinware and similar articles covered and coated with tin, lead, or other metallic coat- ing. A. W. Calvert. Complete Specifications Accepted. (To be published on August 27.) 1913. 17618. Superheaters especially applicable to locomotive boilers. Stirling and Schmidt’s Superheating Company (1910). 17779. Apparatus for absorbing ammonia from producer gas. Mond. 17944. Utilisation of peat. Rigby, and Wetcarbonizing Limited. 18072. Electric furnaces. Crafts. 20216. Unspillable electric accumulator cells. Thomson. 20248. Rotary engines, pumps, and the like. Dock. 21973. Hand coupling devices for railway vehicles. Gray. 23660. Apparatus for inflating divers’ dresses. Draeger- werk Heinr. & Bernh. Draeger. 27338. Manufacture of machine-made bricks and the like. Youngman. 27409. Earthenware troughs for electric cables. Doulton and Morris. 27481. Apparatus for detecting hidden metallic masses. Jullig & Zeschall. 27971. Process for fixing nitrogen by means of ferro- aluminium. Societe Generales des Nitrures. 28055. Discharging apparatus for vertical retorts. Glover and West. 29993. Couplings for railway and like vehicles. Boirault. 1914. 41. Process and apparatus for obtaining ammonia from moist waste substances or peat. Stauber & Kochan. 1037. Centrifugal pump. Michell. 3331. Air cooler for air compressors. MacCamy. 3461. Method of ascertaining disturbances in the frost wall when sinking shafts according to the shaft freezing method. Leimbach. 6608. Explosives. Charbonneaux. 7287. Driving chains of the silent type. Eden, Ailing- ham, and Hans Renold Limited. 9983. Means for securing picks, hammer heads, axes, and kindred tools to their handles or helves. Rees. Complete Specifications Open to Public Inspection before Acceptance. 1914. 11824. Lining for rotary kilns or furnaces. Dynamidon Ges. 17548. Arrangements for regulating the working of hauling or winding machinery. Siemens-Schuckert- werke Ges. 17786. Tunnelling machines. Recen. 17787. Cutter heads for tunnelling machines. Recen. 17876. Manufacture of bricks, tiles, and the like. Hidoux and another. 17882. Manufacture of peat fuel and ammonia from crude peat. Halvorsen. 17961. New explosive body and methods of producing and utilising same. Von Hey. 17972. Apparatus for artificial respiration. Christiansen. GOVERNMENT PUBLICATIONS. *** Any of the following publications may be obtained on application to this office at the price named post free. Dominions Report for 1913-14 : East India Education Progress 1907-1912, 3s. British Museum Return, 1914, Is. 4d. Report on British Shipping in Time of War, 3Jd. Acts, 1914 : Postponements of Payments, Id.; Sheffield University, Id. East India Press Act, 1910 : Railways and Irrigation Works, ljd. Statutory Rules and Orders, 1914 : COAL MINES SAFETY LAMPS ORDER, July 1, 1914, 4|d.; Locomo- tives (Scotland) [1096], l|d. Bills, 1914 : COAL MINES, Id.; National Insurance Act, 1911, Part 2, Amendment, 2[d.; ditto, Id.; Housing Bill Amendment, Id.; Housing No. 2, Id.; Housing, IJd.; Industrial Peace, 5d. ; Patent Designs (Temporary Rules), Id. Consular Reports, 1913 : China, Nanking, 2d.; ditto, Shansi, 2d. Return of Shipping, Suez Canal, 2jd. PUBLICATIONS RECEIVED. Annual Report of the Minister of Mines, British Columbia, Canada, of the Mining Operations for year 1913 ” ; “ Le Mois Scientifique et Industriel ” (No. 178),. June, price 2 fr.; “The Engineering Magazine” (Vol. 47, No. 5), August, price Is.; “The Geological Maga- zine" (Vol. 1, No. 8), August, price 2s.; “Journal of the Western Society of Engineers ” (Vol. 19, No. 6), June, price 50c.; “Report on Mining Operations in the Province of Quebec during 1913.” CATALOGUES AND PRICE LISTS RECEIVED. We have received from Messrs. J. H. Holmes and Company (Newcastle-on-Tyne) a leaflet describing a new oil break switch for A.C. control. These switches are arranged for switchboard mounting, the automatic trip gear being carried by an escutcheon plate arranged for mounting upon the front of the panel. The switch is closed by drawing the handle forward and opened by depressing a catch button carried on the operating lever. On an over- load the trip operates direct on the loose handle arrange- ment immediately the circuit is made, and the switch there- fore cannot be held in on a fault. The no-volt release is of simple construction and certain in action. The fixed contacts are built up of several independent self-aligning fingers, and substantial sparking pieces of similar design are fitted to take the arc well away from the main contacts.. In the smaller size switches, the cable connections are made inside massive porcelain insulators. In the larger sizes the cable connections are attached to heavy copper rods passing up through the switch bracket. For the heavy current switches transformer trips are employed, the transformers being of the ring type for switches up to 1,000 volts, above 1,000 volts wound transformers are provided. Time elements of the oil dish pot type may be fitted to trip coils when required, and those worked from current transformers may be fitted with time element fuses enabling the transformers to be used for instruments as well as tripping coils as preferred. The switches are made in 2, 3 and 4 pole, and any of the usual combinations of trips can be supplied. A leaflet has reached us from Messrs. Mavor and Coulson Limited (Mile-end, Glasgow), describing a new series of gate-end boxes for coal cutters, etc. The boxes are made of the three-pole, two-pole and single-pole types, the last named being used with “ C.C.” concentric wiring. They have a capacity of 50 amperes, and are suitable for pressures up to 500 volts. The boxes are of cast iron with close back, and strong hinged cover closing on a wide machine faced joint, and are of such size that the internal clearances of the “ live ” parts are ample. A gland is fitted to receive, and make mechanical and electrical connection with, the armouring of the roadway cable where it enters the box. The switches are of the knife-blade pattern with quick break, the individual poles are mounted on independent porcelain bases. The switch blades are carried by a common spindle, from which they are insulated with mica, and the spindle is carried by bushings in the structure of the box, through one side of which it projects. When the switch is “ off ” the moving parts and the fuse contacts are “ dead.” The fuses are enclosed in detachable porcelain tubular fuse holders. The fixed contacts are massive and are mounted on extensions of the porcelain bases of the respective switches. The pummel, or contact plug for taking the trailing cable, is of aluminium, the sockets being insulated from the body of the pummel by mica. The plug socket for receiving the pummel or contact plug of the trailing cable is formed as an extension of the gate-end box. The contacts, of massive design, are mounted on a strong porcelain base, and are shielded from accidental contact. An earthing pin is fitted to connect the body of the pummel to the structure of the box. An interlocking device is pro- vided to prevent the cover of the box being opened when the switch is in the “on” position, and also to prevent the pummel being inserted in the socket, or withdrawn from it, when the switch is “on.” DARLINGTON’S HANDBOOKS. Smoke Helmet with Telephone. SMOKE HELMETS (ALL-BRITISH MANUFACTURE) for extinguishing Gob Fires, and for other short distance work in Collieries. A necessary Apparatus for every Colliery to cope immediately with emergencies within short distances from fresh air. Extremely simple. Nothihg to get out of order. ALSO MAKERS OF THE “PPQTO” (Fleuss-Davls Patent) RESCUE APPARATUS, OXYGEN REVIVING APPARATUS. GAS ANALYSIS APPARATUS. SELF-CONTAINED DIVING APPARATUS (no air pumps or tubes) for use in difficult situations where the use of air pumps and tubes would be impracticable. SIEBE, GORMAN & CO. LTD., “NEPTUNE” WORKS, LONDON, S.E. Telegrams—“Siebe, Lamb, London.” Telephone No.—251 Hop. “ Nothing better could be wished for.”—British Weekly. “ Far superior to ordinary guides.”—Daily Chronicle. Visitors to London (and Residents) should use OAKLINGTON’S “ Very emphatically tops them all.”—Daily Graphic. LONDON AND “A brilliant book.”—The Timet. ** Particularly good.”—Academy. By B. C. COOK and Sir EDWARD T. COOK. ENVIRONS. 5th Edition, Revised 6/- 30 Maps and Plans 80 Illustrations. “The best Handbook to London ever issued.”—Liogrpoo? Daily Pott. SO Ulus. Maps A Plans, 5s. NORTE WALES. BO Ulus., « Maps, 2s. «d. N DBVON A N. CORNWALL. 1OO Ulus. Maps A Plans, Os. DBVON a CORNWALL. 50 Ulus., 6 Maps, 2s. 8d. 8. DBVON A 8. CORNWM.T 1OO Ulus. Maps A Plans, 3s.6d. PARIS, I.YONS, A THE RIVIERA Is. 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