91. Mackay, G. Jan. 11.

Materials. — “Spent bleach, soda lime, gas lime, tanner's lime, soap lime,” and other waste lime products are mixed with coal dust and waste alkaline liquors from paper &c. works. The mixture is calcined in a kiln and then used in the manufacture of glass. Sawdust, spent bark, &c. may be used instead of coal dust; and in some cases the addition of alkaline liquor is dispensed with.

175. Vera, P. Jan. 16. Drawings to Specification.

Obtaining metal. — A soluble glass made of sand, carbonate of potash, and carbon is employed for electric insulation.

450. Smith, W. Feb. 6.

Blowing is effected by means of compressed air, forced by a fan, pump, or similar appliance into a reservoir a from which it passes to the working - places through overhead pipes d having flexible or elastic tubes e banging from them within reach of the workmen. A reservoir capable of expansion and contraction, like a gasometer or smiths’ bellows, may be employed, with weights to give the required pressure; or a vessel in the form of an ordinary boiler with a safety-valve b may be used. Each elastic tube may be constructed with a self-closing throat, which opens only when the tube is drawn down by the workman and applied to the blowing-tube ; or it may be formed with an internal valve. Or the tube may be provided with a valve that is self-closing and is opened by the operator pressing on a thumb-piece, in which case the tube need only be flexible and not elastic. Fig. 3 shows a self-closing slide-valve, and Fig. 6 a self-closing tap. The valve is opened by pressing the slide h, i inwards against a spring o, and the tap is opened by pressing a movable arm p towards a fixed arm q against the action of a spring r. In the arrange­ment shown in Fig. 8, a valve or mouthpiece 1 is fitted into an elastic tube 2, and two lateral plates 5 are hung from loops 4 on an external ring 3. The valve is caused to open at 7 by pressing inwards the loose ends 6 of the plates 5.

1336. Huch, E. H. April 13. [Provisional protection only.]

Annealing. — For tempering flat &c. shaped glass, a hot bath of butter or tallow is used. The heating oven has a movable muffle so that by inclining the muffle, the glass may slide out of the oven into the bath.

1338. Jensen, P., [Meusel, R.]. April 13. [Provisional protection only.]

Toughening. — In order to produce glass which is both tough and capable of being cut so that it may be applicable for window glass and other purposes, the glass while still red hot on the blowpipe is dipped into a hot saturated salt solution.

1554. Defries, H. April 28.

Moulding. — Glasses for railway-carriage roof lamps are made with an external foot or ring upon the bottom, to prevent scratching &c. when the glass is rested on the platform. The ring is obtained by means of a recess formed in the pressing-mould, the glass and foot being pressed in one piece and by one operation.

1635. Varley, F. H. May 3.

Moulding. — Relates to a process of casting discs or other forms of accurate and uniform size in metal, glass, &c. A mould is made by clamping together in a frame a number of iron, steel, or other plates of the same thickness as the discs required, and then drilling one or more cylindrical holes through the whole pile. The plates are arranged to project from the pile alternately on opposite sides, and each set of alternate plates is kept together by bolts, rods, or pins. The metal is run into the hole, and the two sets of plates are then pulled in opposite directions by a hydraulic press or by screws or levers so as to divide the column of molten metal into separate discs. After the metal has solidified the plates are returned to their original position and the discs forced out. The metal is preferably ran into the mould at the bottom by means of a U-shaped pipe made of sufficient height to produce dense castings by the pressure of the column of metal. Hydraulic pressure is employed when great density is required. The mould is heated, and is preferably placed in a casing to prevent oxidation. Hydrogen or other non-oxidizing vapours or gases may also be circulated through the casing during the heating of the mould. If several moulds are employed they are preferably heated in reverberatory or gas furnaces to obtain uniform heating. The inlet and outlet pipes of the mould are made in sections so that the cast metal left in them can be taken out and re-melted.

1637. Siemens, F. May 3. Disclaimer.

Toughening; pressing; moulding. — Consists in subjecting glass to pressure in moulds kept at a suitable temperature, and thus simultaneously compressing and hardening it. The glass, after having been partially or completely shaped, is preferably re-heated in a gas-heated oven before being pressed, and to prevent the articles from losing their shape when they are heated, they may be placed in platinum shells, In some cases, however, the partially-formed articles or the liquid glass may be conveyed direct to the moulds. Fig. 9 shows a form of mould which may be used. The lower portion c, rests on a truck and receives a glass sheet p. The truck is afterwards run under the upper portion e, which is then lowered, and, if necessary, pressed down by weights. Similar flat moulds are used for hardening glass plates. When rapid cooling is required, the moulds may be constructed of metal of high conductivity, such as copper, and for a more gradual cooling, iron or earthenware, &c. may be employed. The moulds may be kept at a constant temperature by filling them with liquid, such as boiling water. If some parts of the articles are thicker than others the corresponding parts of the moulds may be made thicker or of some material of greater con­ductivity. In the Provisional Specification it is stated that an oven for heating glass articles preparatory to plunging them into a bath, is made with two compartments, one of which is heated only to a degree at which the softened glass retains its shape, while the other is kept at a higher temperature. The bath is placed at the bottom of the hotter compartment. The articles may be rolled from one oven to the other if cylindrical or globular like lamp glasses or globes, or they may be dropped, or they may be thrown over an intervening partition by a spring let loose by a trigger or by a piston actuated by compressed air or steam. Specification No. 2783, A.D. 1874, is referred to.

1642. Lomax, G. H. May 3.

Moulding; shaping. — The lamp reservoir b, Fig. 1, with a rim d forming a cavity for collecting overflow oil, is first formed as shown in Fig. 2 in a pressure mould, in which the soft glass is driven into the irregularities of the mould by the plunger of a press, and is afterwards shaped as shown by the dotted lines, the rim d assuming an inclined position. Reference is made to the Letters Patent of the United States, No. 40,094, A.D. 1863.

2157. La Bastie, F. B. A. R. de. June 12.

Annealing; toughening. — Relates to improvements in the process and apparatus for tempering glass described in Specification No. 2783, A.D. 1874, which process consists in plunging the glass, when heated to about the point of softening, into a bath, of oleaginous substances at a somewhat lower temperature. The glass is plunged into the bath, preferably in a soft condition, but thin glass may be plunged at a lower temperature and when still hard. The bath, which must be cooler than the glass, is not necessarily heated; it may be formed of pulverulent liquid, or gaseous substances, such as tar, resin, saline solutions, fused sulphur, molten metal, pulverized talc, lycopodium &c, or a current of air may be used. The article may be plunged several times, the baths being of the same or of different character; or the cooling-material may be poured over or directed against the glass, and the article may afterwards be re-heated.

Fig. 1 shows one form of apparatus for tempering flat sheets. The sheets are brought by a travelling metallic web to an opening B, through which they are pushed on to a carriage c in the furnace. The carriage frame runs on rails below the furnace-bottom, and it is moved to and fro by means of a rod c³ passing outside the furnace. The table of the carriage may be also arranged to rotate by mounting it on a vertical spindle and connecting it by bevel gearing to a spindle passing through the wall. The glass, when sufficiently heated, is transferred to an oscillating sole E supported from a counterbalanced shaft e³ by arms e², which are of adjustable length and work through slots in a plate, which slots are provided with sliding covers. The sole is canted by means of a lever towards the mouth of the bath J, and, at the same time, a slide K is raised by a chain attached to the lever. The glass sheet slides down a grating L into the bath J, the grating being carried on side bars pivoted to side frames fixed on a rocking shaft o. Rollers of wire gauze mounted in a frame, may be arranged to bear against the glass as it slides, and the rollers may be made heavier towards the bottom to check the motion. The grating L with the glass is afterwards canted back, and, when horizontal, is held up by a hook r². The side frames are then lowered, and the glass is drawn into a shelved receptacle P mounted within the bath and fixed to a shaft provided with an operating lever, by means of which it can be brought into line with the grating L. The shaft o, where it passes through the side of the bath, is fitted with a cone working in an adjustable conical seat and a spring is arranged to act as a brake. The bath is provided with a skimmer, which consists of a blade worked by an external handle to push the scum along a curved plate into a small wire basket t. The cover of the bath is made in several parts which can be opened separately to obtain access to the different appliances in the bath. The bath is heated by a separate fireplace and flues. The furnace chamber C is heated by a fireplace F, and a portion of the gases pass away through the chamber con­taining the travelling web which feeds the sheets.

Fig. 2 shows an oven for tempering shaped glass, such as wine glasses, tumblers, &c. The sole B, on which the articles are heated, is supported by arms from a rocking shaft and arranged so that when it is horizontal it lies over the bath, which is also covered by a sliding plate f under the sole. The heated articles are raked on to a side shelf, while the sole B is canted to uncover the bath, and they are then pushed into the bath, being guided by inclined wire-gauze h on to a travelling wire web H, by which they are discharged into a basket l. A roller of the web is connected to the treadle by which the sole is canted, so that the web is advanced by the movement of the treadle. A pipe U, for heating small articles, such as lamp glasses, is provided. A wire gauze skimmer g is suspended by arms from a spindle g^l operated by a handle g². For tempering special articles such as mirror plates, or optical glasses, movable or portable baths may be used. In front of the oven mouth is placed a jointed frame with adjusting segments and screws, and a bath fitted with a grating is heated separately and placed in the stand. The glass as it leaves the furnace, is pushed on to the grating, and the bath is removed. Fig. 3 shows an apparatus for tempering lamp glasses and other cylindrical articles. The articles are carried by a rod n, sliding without rotation in a sleeve i, on which is a pulley bearing against a drum K having a winch handle. The glass is pushed into the furnace or pipe and rapidly rotated, and is then plunged into the bath by turning the frame a round the pivot b. The articles may be held by means of a rod fitted with cones or a cone and collar, or with a hollow cylinder of refractory material within which the article is placed. Tongs for holding the articles are made with a third central arm by which the glass can be detached. Small articles such as dishes, cups, &c. may be heated in refractory moulds, which are inverted and allowed to drop into the. bath.

2359. Hyatt, T. June 29. [Letters Patent void for want of Final Specification]

Toughening. — Pressed glass is toughened by dipping into molten lead or other metal, the glass being allowed, in some cases, to cool in the metal.

2669. Heinzerling, C. July 28.

Materials. — Residues obtained in the manufacture of potassium bichromate, iodine, and bromine are used for making common bottle glass. The residues contain ferric oxide, alkaline silicates, calcium sulphate, lime, magnesia, &c.

3307. Monckton, E. H. C. Sept. 21.

Annealing. — The glass is placed either cold or hot in a bath which is gradually heated to a suitable temperature and after remaining hot for some time is gradually cooled down. This process may be applied to glass which has already been annealed in the ordinary way. The ordinary annealing may be done “by means of a hot blast or of superheated steam.” Wrought or cast iron pans or tanks with or without movable covers are used for the baths and may have grooves or divisions in the sides or ends to hold sheets of glass. Taps are fitted at the bottoms of the baths for drawing off the contents, and facilitating washing the glass. The tanks are arranged one above another so that the liquor from one can be run off into the next below and so on into a reservoir at the bottom. The baths may consist of soluble glass, fused chloride of lime, fused soap, or fused salt, such as common salt, saltpetre, alum, “vitrol,” and the sulphates, nitrates, and chlorides of soda, potash, and lime, with the addition of water, or they may consist of grease and oils, preferably mixed with alkaline lyes, with or without the addition of litharge, to form soapy compounds, or of linseed oil and litharge, or of resin, tar, or pitch, or fusible alloys such as those made of tin, lead, and bismuth, or tin, lead, bismuth, and mercury, or tin, lead and spelter. The linseed oil and litharge after use for annealing may be disposed of commercially as painters’ drying-oil, and the oil and alkali as soap. The glass when annealed sufficiently is allowed to cool in the hot water or other solvent used to cleanse it after the annealing - liquid has been run off. The glass may be subjected to a soap bath, a chloride of lime bath, and a fused alloy bath in succession. If the material composing the bath is of greater specific gravity than the glass, the glass is held down by a cover made of iron bars or perforated metal. When cooling off an alloy bath, metal is run off before solidification and is replaced by hot oil, soap, or salt to allow the glass to be cooled gradually. Heated glass, quenched in oil or other liquids cooled down by freezing mixtures may be again fused, worked up, and annealed as described. Instead of using a liquid bath, the glass may be buried in powdered clay in iron vessels which are then hermetically closed and heated by furnaces or the flame from the gas of hydrocarbons “actuated by either an ordinary blast or by a steam blower.” Or the glass may be packed layer by layer in tanks “well closed in very hot sand” or other suitable material, no additional heat being applied. Chemical vessels, dinner and other plates and dishes, tea cups and saucers, tea and coffee pots, cooking-utensils, moulds, spoons, tobacco pipes, and other articles generally made of earthenware or porcelain may be made of glass and annealed as described. Glass so prepared may also be used for making sounding-boards for pianofortes and other instrument, flutes, clarinets, and other musical instruments, and also for organ pipes and harmonium and other musical reeds, supports and bearings for engines, and watch cases, lenses, and glass for optical purposes which are preferably made by pressure in iron or steel moulds.

3677. Lake, W. R., [Branch, J. W.]. Oct. 22.

Cutting glass. — Diamonds used for cutting glass are secured in metallic holders by embedding them in the metal, while the metal is softened by heat. The iron holder D, which is either split or in two separate parts d, d1 is heated to a cherry-red heat and the diamond c placed between the two parts, which are then pressed together in a vice. When securing a diamond, part of it may be left exposed, or it may be completely enveloped and the point of the diamond afterwards exposed.

3751. Sutcliffe, T., and Fewings, J. Oct. 28.

Bottle necks, making. — A bottle for containing aerated liquids is blown in a mould A, Fig. 1, formed with a projection a for producing a corresponding internal projection or seat b in the neck for retaining an internal stopper instead of forming the internal seat b by special tools after the bottle is blown. After the part above the projection b is broken off, a ring is cast round the part b of the neck, and the mouth is worked into the form shown in Fig. 4.

3906. Cannington. E., and Shaw, J. Nov. 10.

Annealing. — An annealing kiln is constructed in the form of a tower with a central partition S, the articles being placed in boxes B carried by endless bands E, which pass downwards on one side of the partition and upwards in the other. The fireplaces use gaseous or other fuel, and are arranged at the lower part of the upcast side, the outlet U to the chimney being placed on the opposite side of the kiln. The boxes B are charged through the openings A, and when full, are raised by the endless chains in order to bring another set of boxes opposite the openings. The articles are afterwards withdrawn through the outlet A¹, the empty boxes travelling below to the packing holes A. The arrangement is applicable to the manufacture of glass bottles by the continuous gas furnace.

4017. Britten, B. Nov. 19. [Provisional protection only.]

Obtaining metal. — Glass is obtained from flint stones, quartz fragments, sand stone, or other suitable mineral, instead of from the sand or comminuted silica commonly used, by heating a pile of the silicious stone in a suitable tank and introducing a more or less continuous supply of the necessary fluxing-ingredients. The tank is preferably made with a floor sloping down to a well in which the glass collects as it runs from the stones.

4063. Hyatt, T. Nov. 23. Drawings to Specification.

Toughening. — Glasses employed in pavement, deck, and other lights, and walking surfaces, are toughened by immersion in molten lead when just made.

4193. Perry, G., and Perry, E. Dec. 3.

Moulding; gathering metal. — Relates to the steam moulding-presses described in Specification No. 3216, A.D. 1872. Instead of arranging the moulds to revolve they are placed upon a reciprocating table A, Figs. 2 and 3, and are arranged in duplicate, one set being placed behind the other, ready for use when the first set becomes too hot. A wooden stop controlled by a handle d is placed in the way of the back of the table A when changing from the front to the back set of moulds. The plungers c¹, c¹¹, c¹¹¹ are provided with rings and adjustable springs and are mounted in a plate v secured by adjusting-nuts v^x to a main plunger C which is reciprocated by a crank shaft h^x driven by a steam engine through a spur-wheel h. The various parts of the press are arranged so that, by operating a single handle i, the moulds are run under the plungers, the plungers caused to descend and return to their raised position, the moulds to advance again, and the moulded articles to be lifted out of the moulds. The table is retained in its forward position by a catch s which is released by the handle i, thus allowing a weight T to pull the table back. A cam U, on the shaft h^x, acting through a rod M and a lever N returns the table after the plungers have bean raised out of the moulds. When the plunger crosshead reaches its highest position, it engages a tappet rod f which, by means of an incline on its bottom end and suitable rods and levers, closes the steam cock l. The cock is re-opened by the action of the handle i on a toggle-jointed bar i¹ allowing the rod f to spring forwards. The false bottoms of the moulds are raised to discharge the moulded articles by levers q, q^x, Fig. 7, engaging stationary inclines on the return of the table. The movement of the rod f, in stopping the press, also releases the levers q, q^x by moving the inclines sideways by means of suitable connecting-rods and levers. The moulds of one set are filled with metal simultaneously by a gatherer consisting of a number of gathering-irons mounted in one frame, as shown in Fig. 8, and arranged to be rotated all by one handle d acting through gearing c. In a modification of the press adapted for hand power, a hand-lever is secured to the shaft h^x, and the plunger is operated by connecting-rods and slotted arms on the shaft.

4552. Bessemer, H. Dec. 31. Drawings to Specification.

Making lenses and reflectors. — Relates to the manufacture of lenses and reflectors for telescopes, helioscopes, cameras, lighthouses, signal lights, daylight reflectors, &c, and to the machinery employed therein. The general form and contour is given to discs or pieces of glass or speculum metal by turning in a lathe, the tool of which moves horizontally about a pivot coincident with the centre of the surface to be formed. The tool is fitted with a piece of carbon, black diamond, or other gem. In the manufacture of very large glass reflectors it is necessary to strengthen or support them so that they will not bend under their own weight. This may be done by fusing together any number of sheets of plate glass; the plates are ground flat and covered with a wash of silicious and alkaline matters, e.g., powdered glass, with or without boracic acid, pearl ash, &c, and they are then put together in a “bung” and heated in a kiln. Or a single plate or sheet may be strengthened by a light strong cellular backing of metal, &c, the faces of which may be formed with grooves placed in communication with an exhausted chamber so as to hold the reflector in position by atmospheric pressure. Several special forms of backings for the reflectors of helioscopes &c. are shown and described. To form reflectors with a short focus and consequently of deep curvature, discs of plate glass are bent in the glass-bender’s oven, and the backings are made of proper shape to fit them.