US1544581A - Furnace for heating rock drills and rock-drill steel - Google Patents

Description

July 7, 1925. 1,544,581

5. HOSKEN FURNACE FOR HEATING ROCK mums AND ROCK 1mm, STEEL Filed Jan. '12, 1924 5 Sheets-Sheet 1 July 7, 1925. I 1,544,581-

s. HOSKEN FURNACE F 0R HEATING ROCK DRILLS AND ROCK DRILL STEEL Filed Jan. 12, 1924 5 Sheets-Sheet 2 July 7, 1925.

s. HOSKEN FURNACE FOR HEATING ROCK DRILLS AND ROCK DRIL Filed Jan. 12, 1924 L STEEL 5 Sheets-Sheet 5 1,544,581 S. HOSKEN Filed Jan. 12, 1924' 5 Sheets-Sheet 4 FURNACE FOR HEATING ROCK DRILLS AND ROCK DRILL STEEL July 7, 1925.

July 7 1925.

s. HOSKEN FURNACE FOR HEATING ROCK DRILLS AND ROCK DRILL STEEL 11m Jan. 12, 1924 s Sheets-Sheet 5 :srATE s omen. 1

Patented July 7, 1925.

r A SAMUEL nosxnm or .JOHANNESBUBQ)IRANSVAAL, SOUTH AFRICA.

I FURNACE FOR HEVATINGROCK nRILLs un ROCK-DRILL STEEL.

Application filed ianuar y 12, 19 2 4. Serial No. es5,s4s'.

T0 allwhomz'tmag/ concern: V

Be it known that LSAMUEL HosK-nN, a subject of the King of GreatBritain, and resident of Johannesburg, TransvaalProvince, Union'of South Africa, have invented a certain new and useful Improvement. in Furnaces for Heating Rock Drills and Rock-Drill Steel, of wl iclrthefollowing is aspecification. f 5 A h This invention has reference to furnaces particularly designed for and especially applicable for heating bars of steel which are to be forged or formed into rook drills,,.or rock drilling machine bits, and for heating s'uch drills, bits or the like preparatory to I certain of the. carrylng means omitted.

re-sharpening the same and also for heating such drills or bits for the purpose of hardening'the Cutting ends ant shanks thereof.

One object of the present invention is to devise an .ele'ctrical furnace in which }the drill or; drill steel can be heated gradually, or in stages, to any desired and predetermined maximum temperature.

1 A further object is to ensure thatthe drill, bit, etcetera, shall pass continuously'through all the stages of the heating process in a predetermined period'or length of time. v

still further object'of the invention is tog ensure thatthedrillor drill steel shall net-itewithdrawn from the furnace during its passage fltherethrough.

Q'According to the. invention the furnace is constructed in or dividedinto any desired and su table number of, sect ons, arranged ins'uch a" manner. that the drills, bits, etcetera,j in the heating process, will travel through the section of the furnace of lowest temperature and continue without stopping through the succeeding sections of gradually rising or higher temperature into the last section, which is heated to the desired maximum temperature.

The means which is'provided for carrying or passing the drills, bits, ,etcetera, through the several sections ofthe furnace are designed so that thei. passage of ,the. drills through the furnace takesiplace during the predetermined period of-timenecessary to raise the drill-s, etcetera, gradually to the desired maximum temperature, and prefers ably sothat the temperaturev or, the drills is raised to-tlie temperature of each section ofthe furnace in their passage through such section. v s

Preferably adjustable-means are provided which prevent withdrawal of the drill or steel during its passage through the furnace. 7 The invention will be fully described with the aid of the accompanying drawings wherein, by way of example,,two embodiments of the invention are illustrated.

In thev drawings,

Fig. 1 isfa side elevation 'of one embodiment ofthe invention, with the means which carry f the drills through thefurnace removed. 7

F'g. 2 is an end elevation of Fig.1"with tain portions of the carrying means.

Fig. 7' is a detail .view of a portion of the heating'chamber of the furnace illustrating ameans for preventing the withdrawal' of the drills from said chamber at any point intermediate the entrance and exit i I Fig. ,8 is a side elevation of the other embodiment of the invention with aportion of thei means for carrying the drills omitted, an v [Fig-9 is a half-sectional end elevation of the furnaceillustrated in Fig. 8.

j-Referring to the embodiment; of the invention illustratedin Figs. 1 to 6 of the drawings, the furnace is soconstructed and arranged that the drills are passed or car ried through it in a verticalv or upright position. In this form of the invention I provide a suitable supporting framework 1 which carries the two plates 2, 3, which form a divided tableupon which is erected and secured the several sections of the heating chamber or furnace proper. Each section of the arched heating chamber 4, as shown,

,formed by the two side'bricks or blocks plates 2, 3, of the table.

Each sect-ion of the heating chamber 4 is comprising the two parts 9, 10, which are connected together at the top, as indicated at 11," and are hinged at the sides, as indicated at 12 and 13, to the vertical plates 14, 15, which are fixed to the top of the table and extend the full length of the furnace at.

the outside of the side bricks 5, 6, of all the sections of the furnace. The space between the casing 9, 10, and the bricks 5, 6, 7, may be filled with any. suitable heat non-conducting material.

For the purpose of heating the furnace electrically heating elements 16, 17, are shown arranged upon the side bricks or blocks 5, 6, inside the chamber 4, at opposite sides of the opening 8, said elements being electrically connected by suitable conductors 1s, 19, 20, 21-, 22. r

The number of sections comprised in the furnace structure and consequently the aggregate length of the heating chambers provided by the said sections is designed to accommodate the number of drills, which it is required to heat in a given period of time, in such a way that the drills attain the temperature of each section before passing into the next succeeding section of higher temperature. The temperature gradient or gradually rising temperature of the furnace is obtained by heating each-successive section a greater temperature than the preceding section fromIthe entrance to the exit.

The means shown for carrying or passing the drills, etcetera, through the furnace include a framework 23 connected to the framework'l and to the part 2 of the table, which framework 23 supports two oval endless tracks or rails 24,25, one side of each of which tracks is arranged beneath the fur nace slightly at one side of the opening 8 7 into the heating chamber 4. The drills 26 areattached to and carried through the furnace by an endless chain-like structure including links 27 to. which are attached the carriers 28 which are provided with grooved wheels orrollers 29, 30-see Figs. 2 to 6 which run on the rails or tracks 24, 25, respectively. Each of the carriers 28 is provided at the upper end with means for attaching thereto the drill 26. The means shown for accomplishing this includes the formation of .a recess 31 to take the stem of the dri'll26 and a screw 32 which, when screwed in one direction secures the drill in said recess 31, and in the reverse direction, disconnects the drill and allows it to be removed from the carrier 28. The carrier 28 is shown provided with two rests 33, 34, which are recessed to take the stem of the drill 26, as shown in Fig. 2, and operate to steady the. drill'26 and ensure its proper alignment as it is being carried through the furnace.

'in' turn driven by a worm wheel 43 off the worm 44 driven by the motor 45.

To ensure the drills being placed at the correct height in the carriers 28 to pass through the heating chamber 4, a gauge is provided comprising a plate 46 fixed to the frame 23. In attaching the drills 26 to the carriers 28 they are placed in the recesses 31 and rests 33, 34, and held against the underside of the gauge plate 46 while being secured to the carriers by the screws 32.

The furnace is designed to prevent the withdrawl of the drills in their passage therethrough. This object is attained by making width of the opening 8 at the bottom'of the heating chamber 4 of such a width that the head or enlarged cutting end of the drill is unable to pass there through. If it be desired to make provision for the heating of smaller drills,-the heads of which would pass'through the opening 8 then this may. be effected by providing means for altering the width of the opening. Such a means is illustrated in Fig. 7 in which a pair of eccentrically mounted rods 47, 48, aremounted in brackets 49, 50, and

have levers 51, 52, fixed on their outer'ends for placing and retaining the eccentric rods 47, 48, in the requisitepositions to givethe desired width of opening between them.

The levers 51, 52 are'provided with, catches V which co-operate with notched quadrants 53, 54, for retaining the said levers in position after the adjustment of the eccentric rods 47, 48.

In the embodiment of the invention illustrated in Figs. 8 and 9, the furnace is so arranged that the drills are passed through it whilst being supported and carried in a horizontal position. In this form the furnace is constructed to provide the central heating chamber 55, said chamber being formed between the bricks or blocks 56 arranged in and carried by the upper portion 57 of the framework and the blocks or bricks 58 arrangedin the lower casing 59 which 'is supported by a pedestal 60. The ids of the framing of the upper portion of the furnace are carried by a suitable frame work or supports 61.

The furnace is provided at both sides with openings 62, 63, leading into the heating chamber 55 so that two rows of drills can be heated simultaneously, two of the carrying means being provided, one at either sidei ofin'the carriers or rests71 and pushedup the furnace. 62, 63, are the electrical heating elements. g

The driving arrangements forthe carrying meansin this construction is the same for both sides of the furnace. and includes two horizontal shafts 64, 65,'through onefof which the motion may beimparted to the carrying means. These shafts run in intermediate and end bearings 66, 67,respectively, the intermediatebearings being carried by the pedestal 60, and the end bearings by separate pedestals- 68. On'each of the shafts 64, 65, at both sidesof the furnace there are mounted two sprocket wheels 69, 70.

The carrying means comprises, for each side of the furnace, a pair of endless chains. One chain engages with the two sprocket wheels 69 nearest the side of the furnace, and

the other with the two sprocket wheels 70,

on the outer ends of the shafts 64, 65. The links of the chains are constructed to form the rests or carriers 71 for the drills 72.

The two chains are connected by. means of rods 7 3 on theouter ends of which there are mounted rollers 74, which are engaged by the teeth of the sprocket wheels to operate the chains to convey the drills through the furnace. Both ends of the rods 73 are connected by means of smaller links 7 5 to impart the requisite rigidity to the carrier structure.

76 are two rails arranged. at either side of the furnace and supported by the framework 77, in front of the openings 62, 63, through which'the drills 72 project into the heating chamber-55. Onthese rails 76'the rollers 74 of the carrier structure travel as they convey the drills through the furnace. This ensures the drills being maintained in the correct horizontal or substantially horizontal position as they pass successively through the sections of the furnace of varying temperature .gradually to attain the maximum temperature in the predetermined period of time, which will depend upon the nature of the steel to be heated. I v If desiredmeans may be provided for rotating the drill, etcetera, as it is passing through the heating chamber '55. As shown in connection with Fig. 8, the rotation of the drill may be effected by providing the drill carrier 71 with say two rollers 78, one at either side of the rest 71, which-rollers will be driven by frictional contact with the rollers 74, and by contact withzthe drill 7 2- Which will lie between them-rotate the latter. v

In this embodiment of the invention the gauge or loadingplate 79, whichis in the form of a vertical plate,1 is fixed to the framework and aligned to the centre of the heating chamber 55. As in the previously described furnace'the drills '72 areplaced to the gauge or loading plate 79, and are various sectionsof gradually rising tempera ture, and may be removed from the carrying. means after they have passed outaof the furnace or be allowed to fall out: of the rests 71 as the latter pass around the sprocket Wheels at the exit end of the furnace. To ensure that the drills, shall only be removed from the carrying means after they have passed completely through the furnace," the bricks or blocks 56, 58 are formed with projections 80 which are arranged at such .a distance apart that ordinarily the head. of thedrill cannot pass out of the furnace between said projections. If, however, it be desired to heat drills having heads of such a size as will pass between the projections 80, means, similar to that illustrated in Fig; 7 may be employed to prevent the drills being withdrawn from the furnace during their passage therethrough. The. furnace according to this invention is capable ofheating rock'drills or drill steels of any different ordinary lengths.

' A furnace constructed for the electrical deleterious fumes given off as is the case with furnaces in which fuel is consumed.

'Any suitable electrical control means may be used formaintaining the. desired tempera ture in the various sections or zones of the furnace, and particularly'the maximum or final temperature, according to the grade or class of steel being heated, thus obviating the possibility of overheating or. burning of the steel.

The predeterminedtime periodi necessary for the heating of the drills can be set and automatically controlled and can be that best suited to the nature of the steel to be heated. By the adoption of the furnace, once thedrills have been placed in the conveying means,- and in the case of the verti- .furnace constructed as above described, it

will 'be necessary first, to I determine the period of time that it is necessary and desirable to take'in heating the drills, or raising them to the desired maximum temperature. This will depend on the carbon content of the steel and other physical properties thereof, and the speed at which the conveying means carries the drills through the furnace is then adjusted or set to ensure that the steel or drill shall "be carried through thefurnacein such period of time. l/Vhat I claim as my invention and desire to protect by Letters Patent is v 1. An electrical furnace for heating rockdrills and rock drill steel, comprising a plurality of independently heated sections providing a continuous heating chamber of different gradually rising temperatures from one end of the furnace to the other, incombination with mechanical means for continuously conveying the drills or drill steels which are to be heated through said heating chamber, and means for preventing the withdrawal of the drills or drill steels from the furnace during their passage therethrough, as set forth.

2. An electrical furnace for heating rockdrills and rock drill steel, comprising a plurality of independentlyheated sections providing a. continuous heating chamber of different gradually rising temperatures from one end of the furnace to the other, in combination with mechanical means for continuously conveying the drills or drill steels which are to be heated through said heating chamber, and adjustable means for preventing the withdrawal of the drills or drill steels from the furnaceduring their passage therethrough, as set forth.

3. An electrical furnace for heating rockdrills and rock drill steel, comprising a plurality of independently heated sections providing a continuous heating" chamber of different gradually rising temperatures from one end of'the furnace to the other, in combination with mechanical means in the form of an endless chain-like structure for continuously conveying the drills or drill steels which are to be heated through said heating chamber, and a guage engaging with that end of the steel which is to be heated to ensure the drills or drill steels being placed in the conveying means in the correct position to enter the heating chamber, as set forth.

" 4..An electrical furnace for heating rockdrills and rock drill steel, comprising a plurality of independently heated sections providing acontinuous heating chamber of difierent gradually rising temperatures from one end of the furnace to the other, in combination with mechanical means for continuously conveying the drills or drill steels which are to be heated through said heating chamber, and means for preventing the withdrawal of the drills or drill steels from the furnace during'their passage therethrough, the mechanical means for conveying the drills being in the form of a chain-like structure includingcarriers for the drills or steels, said carriers having recesses in which the'drills or drill steels are placedand carried, linkslconnecting said carriers, and a pairof-rollers for each carrier-upon which said carriers are mounted, rails upon which said rollers are adapted to travel and driving means for the chain-like structure, said driving means including. rollers mounted on the carriers and a-driving sprocket wheel adapted to engage said rollers to movethe chain-like structure as set forth.

5. An electrical furnace for heating rockdrillsand rock drill steel, comprising a plurality of independently heated sections providing a continuous heating chamber of different gradually rising temperatures from one end of the furnace to the other, in combination with mechanical means for continuously conveying the drills or drill steels which are to be heated through said heating chamber, means for preventing the withdrawal of the drills or drill steels from the furnace during their passage, therethrough, andmeans for rotating the drills or drill steels during their passage through the chamber, the mechanical means for conveying the drills or drill steels .being in the form of a chain-like structure including carriers for the drills or steels, said carriers having recesses in whichthe drills or steels are placed and carried, links connecting said carriers, a pair of rollers for each carrier upon which said carriers are mounted, rails upon which said rollers are adapted to travel, and driving means for the chain-likestruc- .ture, said driving means including rollers mounted on the carriers and a driving sprocket wheel adapted to engage said rollers to-movethe chain-like structure, and the means for .rotating'the drills or drill steels during their passage through the chamber being in the form of rollers mounted upon the carriers and running in contact with the first-mentioned rollers and the drills or drill steels, as set forth. 7

6. A furnace of the nature indicated comprising a plurality of sections providing a continuous heating chamber of different gradually rising temperatures in combination with means for conveying the steel articles which are to be heated through said heating chamber and means for varying the width of the. opening into the heating chamber to prevent withdrawal of the steel articles during their passage through the heating chamber, as set forth.

7. A furnace of the nature indicated comprising a plurality of sections providing a continuous heating chamber of different gradually rising temperatures, in combination with means for conveying the steel articles which are to. be heated throughsaid heatingchamber and means forgvarying the Width of the opening into the heating chamber to prevent Withdrawal of the steel artioles during their passage through the heating chamber, said means including eccentrically mounted rods and levers for rotating said rods, as set forth.

In testimony whereof I have signed my name to this specifieation in the presence of two subscribing Witnesses SAMUEL HOSKEN.

\Vitnesses:

G. A. VVEBB,

CHAS. OVENDALE.

Images