988 THE COLLIERY GUARDIAN. Novembeb 6, 1914 ABSTRACTS OF PATENT SPECIFICATIONS RECENTLY ACCEPTED. 1930 (1914). Improvements in or Connected with Cutters for Bars, Discs, and the like, and Cutter Bars, Discs, and the like of Machines for Use in Mining. Mavor and Coul- son Limited, and S. M. Mavor, both of 47, Broad-street, Mile End, Glasgow.—According to this invention, a shank and its socket in cross section are each of oval, or sub- stantially oval, form; for example, it may be elliptical. The shanks and sockets of cutters may be arranged with the major axis of the cross section in any direction; for instance, b1, and forces same to the left until port y is opened to exhaust. The pressure on the right hand side of main valve v drops by exhausting via ports x and y, and the con- stant pressure on the plunger h again forces the valve to the right. Exhausts are also provided at the parts marked s and t. In an alternative form of construction, a ball may crum of the double bell crank lever, and will, therefore, move the double bell crank lever with an accelerated motion, so that there is a further factor which tends to still further accelerate the governor relative to the scroll shaft 2. If in some cases the major axis may be in alignment with the direction of motion of the cutter, or it may be at right angles thereto. The shanks and sockets may be of regular cross section from one end to the other, or tapered, and in some cases the tapering may be restricted to two opposite sides merging into two parallel sides. If required, provi- sion may be made for preventing endwise displacement of the shanks in their sockets. Some examples of construction according to this invention are shown in the accompanying drawings. (Eight claims.) 5102 (1914). Improvements in Shackles for Coupling Col- liery Trams or the like. A. J. H. Boyton, Highdene, 11, Stanwell-road, Penarth, Glamorgan. — Relates to shackles for coupling colliery trams or the like, and its object is the provision of means for readily securing a shackle pin from jolting out of the eye of the shackle; from which it is with- drawn to release the coupling whilst being adapted to be easily released from the securing position. Whilst being particularly adapted to colliery trams, it can be used for any other purpose for which a locking pin is required. In the accompanying drawings figs. 1 and 2 represent the pin in the locked position, fig. 1 in elevation and fig. 2 in plan. The coupling consists as usual of a U-shaped shackle A, through eyes in the extremities of the jaws, of which a headed shackle pin B is fitted. According to the invention, the end of the shackle pin remote from the head is dia- metrically forked or slotted. A slotted key piece C is fitted loosely in the slotted end of the shackle pin, and secured thereto by a pin D, extending from the one side of the replace the piston form of plunger h. The plunger may in some cases be located in the valve chamber covers in the manner illustrated in fig. 3 of previous patent, No. 5549/12. (Two claims.) 19428 (1913). Improvements in and Relating to Drills, Bits, and like Appliances for Boring in Earth, Rock, and the like. W. H. Wakfer, of 67, Whitworth-road, South Norwood, Surrey, and S. Peck, of Calbourne, Wallington, Surrey. — Has for its object to improve the cutting or boring capacity of these instruments, to lessen the cost of the upkeep of the tools of this character, and generally to increase the life and efficiency of such tools, while at the same time reducing the labour involved in the manufacture and handling of them. According to the invention, the cutting end of the boring head or bit of the type just referred to is formed with a central hole or socket adapted to receive the shank of a centre bit or cutter, which centre bit is arranged to act as a central guide to the cutter head. The shank only of the centre bit being inserted into a hole or socket in the end of the cutting head, it follows that the body of the centre bit or centre cutter, when the latter the governor should exceed its pre-determined speed, it will, through the various rods and beams, control the valve 52 to open the brake engine 83 to live steam and cause the same to brake the drum. (Four claims.) 23418 (1913). Improvements in or Relating to Apparatus for the Distillation of Coal or other Solid Material. T. Hughes, of Danes Inn House, 265, Strand, London, W.C. —Has particular reference to apparatus for the low tempera- ture distillation of coal, its object being the construction of a retort simple in form and efficient in operation. A retort, according to this invention, is so arranged that a layer of large area but shallow depth of the material to be treated is supported against each side of a hollow wall containing heating flues by a wall or partition having openings or pas- sages through which the products of distillation can pass to an outer chamber, which is preferably formed by a metal casing to facilitate condensation. The wall or partition which supports the thin layer of material against the heat- shackle pin across the slot therein, and through the slot in the key piece. The slot in the key piece is so inclined, relatively to the axis of the key piece, that when the key piece is turned end for end about the transverse pin through the shackle pin, the key piece is either coaxial with the shackle pin, and does not project sufficiently beyond the diameter of the shackle pin to prevent its withdrawal through the eye or eyes of the shackle, or, in the reverse position, the key piece and shackle pin are not coaxial, and a portion of the key piece protrudes laterally from the slotted end of the shackle pin, and by engaging the border of the respective eye of the shackle, precludes withdrawal of the shackle pin. The key piece is preferably an elongated rectangular plate, with one end rounded off, and with a slot extending from the middle at one end to near one side edge at the other end. To afford additional security, the shackle pin may be provided with a short lateral feather, and the eye of the upper jaw of the shackle with a corresponding feather way or groove, the two having to be brought into alignment before the shackle pin can be withdrawn. (Two claims.) 13726 (1914). Improvements in Valve Apparatus for Per- cussive Rock Drills, Tools, and the like. G. Rayner, of Grange Farm House, Carterknowle-road, Abbeydale, Shef- field, Yorkshire. — Is an improvement or modification of patent No. 5549/1912, and has for its object the simplifica- tion of the rock drill valve apparatus described therein. The accompanying drawing illustrates a sectional elevation of the improved form of valve apparatus. Air is admitted at the inlet a, and passes by annular groove a1, and the valve chamber via port b, to the left of the piston p, and drives same to the right. .The valve is held in position shown by air fed constantly, in any position of the main valve, by groove g, and port f, to the right hand side of plunger h. As the left hand side of the main valve is constantly open to exhaust by ports m and n, no accumulation of compressed air can take place in the left hand area of the main valve, and in the position shown the right hand side of the main valve is open to exhaust by port x, communicating with main cylinder and outlet y, open direct to exhaust. There- fore, in the position shown, the air acting on the right hand side of plunger h locks the valve securely in position. When the piston has completed part of its stroke to the right, the annular recess p1, formed therein comes into communica- tion with main inlet by port a2, and finally puts a2 in com- munication with port x. The air then flows to the right hand side of the main valve v, and forces same to the left. Constant pressure is still maintained on the plunger h by port /, from main inlet a to a1. Air now flows to right hand of main piston p, via annular groove a1, and the port nil F/C.S. is in position, overlaps or stands out beyond the inner ends of the circular series of cutting edges on the end of the head, the said inner ends being thus protected by the centre bit, which prevents pieces of rock or stone from lodging or being forced in between the cutting edges and the centre bit. Owing to the pronounced projection of the centre bit or centre cutter, a very strong guidance is given to the cutting head, whereby much more efficient working is attained. The main boring head or bit may be of the winged or other cross section type, and may be readily attachable to and detach- able from the tool bar. The head may be hollow for the whole of its length, and the tool bar also may be hollow if desired. With a winged head or bit of this nature the cutting edges would be produced by suitably forming the end faces of the wings or other suitable formations. Bits of so- called x-section or +-section may be used with advantage, but heads or bits having any number of wings may be employed, or the bits may be of prismatic and pyramidal formation. The accompanying drawings show various forms of construction. (Ten claims.) 23647 (1913). Improvements in or Connected with Apparatus for the Prevention of the Overwinding of Colliery Cages and the like.—E. E. Taylor, of 162, Eshton-terrace, Oakenshaw, Bradford.—Relates to improvements in or con- nected with apparatus of the type in which variable speed gearing is provided between the winding engine and the governor to impart a gradually increasing speed ratio to the governor relative to the engine towards the end of the wind, to enable the governor to have an effective control- ling influence over the engine to the end of the wind. The invention lies in the special arrangement of variable gear, and the method and means adopted for operating the same, and for connecting it up to the various parts to be con- trolled. Fig. 1 sets forth the general arrangement of the parts of an apparatus for carrying out the invention; fig. 2 is an enlarged view of the scroll device; figs. 3, 4, and 5 are enlarged detail views hereinafter referred to; fig. 6 is a view of the brake engine taken at right angles to fig. 1. Broadly, the action of the device is as follows : On the wind being begun the shaft 2 and scroll 5 will be rotated, and from it the counter shaft 15, which with the worm 26 mounted on it, will rotate the disc 29. On the cage reach- ing the point where its motion should begin to be checked, one of the stops 30 on the disc will come into contact with the respective arm of the double bell crank lever 31, and turn the same to pull the plunger or rod 33 from the scroll, and so accelerate as above described the motion of the sleeve 8 about the scroll 5. This accelerating motion is directly communicated from the sleeve to the governor by the gear- ing 16, 17. As the double bell crank lever 31 is mounted at a point above the centre of the disc, the stops 30 on the same as they rotate will tend to come in towards the ful- ing surface is conveniently in the form of a louvred casting, the angle, of the louvres being such that there is practically no tendency for the finely-divided material to flow out through the openings. In one convenient construction the chambers are annular and concentric, but this need not necessarily be the case, for the form or arrangement may vary to suit requirements. Fig. 1 is an elevation of one construction of retort according to the invention; and fig. 2 is a vertical section partly on the line 2—2 of fig. 1. (Three claims.) 25159 (1913). Improvements in and Relating to Railway and like Wagons. W. H. Lewers, of 33, Barrow-road, Streatham Common, London, S.W. (A communication from abroad from Percy Grant and Company Limited, of 25, de Mayo 158, Buenos Ayres, South America.)—Relates to improvements in and relating to railway and like wagons of the kind known as flat or low sided wagons (as distinct from those having permanently fixed side and end walls), . !!| I 11 i II Il I i! II 1 1 U such, for instance, as those used for the conveyance of timber. The invention has for its object an improved con- struction of the standards and guides or clips, such that the standards have simple upward and downward movements for respectively placing them in and removing them from their effective position, the construction being further such that the hereinbefore mentioned slot (previously employed) in the standard—which ha