US2035312A - Continuous strip annealing furnace - Google Patents

Description

March 24, 1936. H. c. GREER El AL CONTINUOUS STRIP ANNEALING FURNACE Filed July 27, 1933 5 Sheets-Sheet l r e 4 3 wig w wwci fi N 3 a hf. m 252 Wfl A mm a a Q. R 3% .5 R mu J O my .g Q \Q m T L m\ CR. mm hm N March 24, 1936. H. c. GREER El AL CONTINUOUS STRIP ANNEALING FURNACE Filed July 2'7, '1933 5 Sheets-Sheet 2 INVENTORS H C. Greer H. C. Cage! RJ 6 make! 8. gybarg A. r/eaman M M Rose 7 BY ATTORNEYS Mam]! 1936- l-l. c. GREER ET AL CONTINUOUS STRIP ANNEALING FURNACE Filed July 27, 1933 5 Sheets$heet 3 INVENTORS H0. Greer her A. ff/edian M M Rose ATTORNEYS March 24, 1936. Q GREER r AL 2,035,312

CONTINUOUS STRIP ANNEALING FURNACE Filed July 27, 1935 5 Sheets-Sheet 4 .98 56 7 161 mm a 3 5 5 g 7 I74 176 a J3 49 177 a /72 165 1 museums 170 95 17/ 45 169 2.9 4 56 msuuno'u V I 46 INVENTORS 5'5 54 H c. Greer M6260 R (Shoemaker s. N b A. rvg d man BY M M Rose 7 March 1936- H. c. GREER El AL CONTINUOUS STRIP ANNEALING FURNACE Filed July 27, 1953 5 Sheets-Sheet 5 n I A n e I. n.

illil'IiI'l/Illlllll;

INVENTORS H 6. Greer H C. Cap eel R, (4 films/flake! 8. N Day AfZ/e man M. M. Rose ATTORNEYS Patented Mar. 24, 1936 PATENT OFFICE CONTINUOUS STRIP ANNEALING FURNACE Herbert G. Greer, Morgantown, W. Va., and Herman 0. Cappel and Robert W. Shoemaker, New

Philadelphia,

Stone Nyberg, Dover, Adolph Friedman, Cleveland, and Milton M. Rose, East Cleveland, Ohio Application July 27', 1933, Serial No. 682,430

6 Claims.

The invention relates to a furnace for the continuous annealing or heat treating of strips of ferrous or nonferrous metal.

An object of the improvement is to provide a furnace through which one or more strips of sheet metal may be continuously passed at a uniform rate of speed, the strips being first heated to the necessary temperature required for the annealing or heat treatment desired and then cooled to the temperature required for the annealing or heat treating desired and quenched in a single continuous operation.

Another object of the improvement is to provide a furnace of this character in which the strips are passed first through a' heating chamber where they are brought up to the required temperature and then through a cooling chamber of relatively small cross sectional area in a preoooling chamber of relatively small crosssectional area and a final cooling chamber of larger cross sectional area than the precooling chamber but of considerably less cross sectional area than the heating chamber.

Another object is to provide a furnace of this character having a heating chamber provided with spaced pairs of rolls, each pair being connected to one side of an electric circuit, the circuitbetween the two pairs of rolls being completed through the strip for rapidly heating the strip to the desired temperature, a cooling chamber of relatively small cross sectional-area being located beyond the heating chamber for rapidly cooling the strip.

A further object is to provide means for driving the second pair of rolls at a slightly greater speed than the first pair in order to compensate for any elongation of the strip due to heating of the same, a friction clutch being provided upon said second pair of rolls for preventing tearing or unduestretching of the heated strip.

Another object is to -provide-means for water cooling each set of rolls in order to prevent undue heating of the same.

A further object is to provide means for admitting hydrogen or a mixture of nitrogen and hydrogen, or other gas to the furnace forproducing bright annealing; or for admitting steam for blue annealing; or for admitting a vapor from nitric acid and/or hydrogen and nitrogen, or a vapor of sulphuric acid and salt, for producing a silver gray finish or etched effect upon the strips.

Another object of the improvement is to provide means for circulating water or other cooling agent through the cooling chamber, but not in contact with the strip, for the purpose of rapidly cooling the strip.

A still further object is to provide means for adjusting the rolls so as to place more or less tension upon the strip passing between the rolls in order to varythe softness or hardness of the strip.

A still further object is to provide means for varying the tension at different points throughout the length of the rolls in order to anneal one edge of the strip softer than the other edge or to anneal the edges of the strip either softer or harder than the central portion thereof.

The above objects, together with others which will be apparent from an inspection of the drawings and the following description or which will -be further pointed out, may be attained by constructing the improved furnace in themanner illustrated in the accompanying drawings, in which Figures 1a, 1b and show a sideelevation of the improved furnace;

Figs. 2a, 2b and 20 show a top plan view of the same;

Fig. 3 is a transverse sectional view through the pre-cooling chamber taken on the line 33, Fig. 1b;

Fig. 4, a transverse section through the final cooling chamber taken on the line 4-4, Fig. 1b;

Fig. 5, an enlarged side elevation of the heating chamber portion of the furnace;

Fig. 6, an enlarged vertical longitudinal sectional view through the heating chamber taken on the line 66, Fig. 2a;

Fig. 7, an enlarged side elevation of the heating chamber portion of the furnace showing the opposite side from that illustrated in Fig. 5;

Fig. 8, an enlarged fragmentary sectional view through the first pair of rolls taken on the line 8--8, Fig. 5;

throughout the drawings.

A'strip to be annealed or heat treated in the improved furnace may be formed into a coil as shown at l2 in Figs. 1a and 2a and placed in a box l3 located near the charging end of the furnace, the free end of the strip being preferably passed upward over a pulley l4 and then down around a pulley I5 located within a tank or trough l6 adapted to contain oil or the like as indicated at IT.

The pulley 14 may be journaled in vertically adjustable bearings l8 slidably mounted in a depending supporting frame or bracket I 9, cables provided with counterweights 2| being connected to the bearings l8 and located over pulleys 22, upon the frame or bracket l9, for the purpose of normally taking the slack out of the strip between the box l3 and tank It.

pensates for the time required 'for welding or otherwise attaching the ends of strips together so as not to interfere with the continuous movement of the strips through the furnace.

The furnace proper includes the heating chamber 26 which may be mounted upon a table or bench comprising the metal top plate 21 and the uprights 28. bottom wall of the heating chamber, the side walls 29 and end walls 29' being preferably formed of metal plates. The top wall of the heating chamber may be in the form of a removable cover 30 having depending angular flanges 3| at its edges adapted to extend into the trough 32 surrounding the upper portions of the side and end walls and adapted to contain water, sand or the like for forming a gas-tight seal.

Two spaced pairs of rolls formed of brass, bronze or,other suitable metal are located within the heating chamber26, the upper and lower rolls of the first pair, located at the receiving or charging end of the chamber, being designated by the numerals 33 and 34 respectively, while the upper-and lower rolls of the second pair, or that adjacent to the discharge end of the *heating chamber, are designated by the numerals 35 and 36 respectively.

Each of these rolls is preferably hollow, as illustrated in the drawings, for the purpose of circulating water or other cooling medium therethrough. The necks or shafts 31 and 38 of the rolls 33 and 34 respectively are preferably hollow for the purpose of admitting water or other cooling agent to the rolls, and for the same purpose the necks or shafts 39 and 49 of the rolls 35 and 36 respectively are also preferably hollow.

In order to circulate water or other cooling agent through the hollow shafts and rolls, a hose 4| is connected to one end of each shaft for inlet and discharge of the water or other cooling agent while the opposite ends of each pair of shafts are connected together by a U-shaped hose 42, water-tight swivel connections 43 being pro- The table top 21 may form the a charging opening 44 at the level of the bench of the rolls 33 and 34. This charging opening is preferably provided with a neck 45 having the angular flange 46 surrounding the same to which the flange 41 of the charging tube 48 may be connected as by bolts 49, a gasket 50' being preferably provided between the flanges to produce a gas-tight joint.

The charging tube 48 extends downward at an angle from the heating chamber, the lower or inlet end thereof being located beneath the level of the oil in the tank [6 as best shown in Fig. la so as to form an air-tight seal atthis point.

A pair of small rollers 5| is located within the lower portion of the charging tube 48 and preferably covered with suitable absorbent material tube 48 is located a pair of guide-rollers 52 having substantially V-shaped peripheral grooves 53 to receive the edge portions of the strip and guidethe same through the charging opening 40 to the rolls 33 and 34. .The guide rollers 52 may be adjusted for strips of various widths by means of the adjusting screws 54 and in Fig. 10. o

A stack 56 may be located at the upper end of the tube 48 and provided with an outlet 51 controlled by avalve 58 by means of which the gases produced by the drying of the oil upon the strip, as it passes through the tube 48, may escape. In order to accelerate the drying of any oil which remains upon the strip after passing through the Wiping rolls 5|, 'a' gas burner 59 may, be located beneath the tube 48. This gas burner may also be used to preheat the strip before it enters the heating chamber.

'For the purpose of driving the rolls 33, 34, 35 and 36, a motor 60 may be located beneath the table 21,- the shaft 6| thereof having a small sprocket 62 fixed thereon. A sprocket chain 63 is located over this pinion and over a large sprocket 64 fixed upon the shaft 65 journaled in nuts 55 as shown bearings 66 mounted upon a. cross-frame 61 supported by the uprights 28 of the) table.

A small sprocket 68 is fixed upon the shaft 65 and the sprocket chain 69 is located over said pinion and around the large sprocket l9 fixed upon the 'shaft H journaled in bearings 12 mounted upon thecross-frame 61.

e A pair of small sprockets 13, preferably of the same size, is fixed upon the shaft H and a sprocket chain 14 is located around one of said sprockets I3 and around a large sprocket I5 fixed upon the shaft 38. A sprocket chain 16 is located around the other sprocket 13 and around a large sprocket 11 mounted upon the shaft 40, the sprocket 15 being slightly larger than the sprocket 11, whereby the rolls 35 and 36 will be driven at a slightly greater surfacespeed than the rolls 33 and 34 in orderto compensate for elongation of the strip due to the rise in temperature therein and to keep the strip tautas itpasses through the heating chamber.

Gears l8 and 19 are fixed upon the shafts 31 and 38 respectively and mesh with each other for the purpose of causing the rolls 33 and 34 to both be driven in unison and for the purpose flange 84 of a sliding sleeve 85 upon the shaft, a'

spring 86 being located between said sliding sleeve and the collar 81 fixed upon the shaft, whereby.

the sprocket 11 is frictionally mounted upon' the shaft 40 so as to normally drive said shaft but arranged to slip upon the shaft to prevent tearing of the strip.

The shaft 38 is journaled in bearings 88 fixed in the uprights 89, mounted upon the table 21, and having suitable bushings 90 therein. The shaft 31 is journaled in bearings 9| also provided with bushings 92 and slidable within vertical slots 93 in the uprights 89, a coil spring 94 being located between the underside of each bearing 9I and a suitable socket 95 in the lower end of the slot 93 while a similar coil spring 96 is located between the upper end of each bearing ill and a socket 91 in the upper end of the slot 93, an adjusting screw 98, operated by a knob or wheel 99 engaging the upper end of each spring 96 to compress the same in order to vertically adjust each bearing 9|. Thus the upper roll 93'may be adjusted relative to the lower roll 94 to accommodate strips of various gauges. 7

It has also been learned by experience that by placing more tension upon one end of the roll 33 than upon the other end, one edge of the strip may be annealed softer than the other edge. In the same manner, the edge portions of the strip may be annealed either softer or harder than the central portion thereof by slightly convexing or concaving the surface of one of the rolls 33 or 34.

In order to provide an air-tight seal around the shafts 31 and 38, at the points Where they pass through the side walls of the heating chamber, and at the same time to permit the vertical adjustment of the upper shaft without breaking the seal, a casting or the like as indicated at I is connected to each side wall 29 as by the bolts IN, a sheet of asbestos or the like as indicated at I02 be ng interposed therebetween.

Tubiflar portions I03 are provided upon the casting to surround each of the shafts 31 and 38, these tubular portions being of larger inside diameter than the exteriors oi the shafts, as are also the openings I04 in the side wall 29, through which the shafts are located. Angular flanges I surround the outer ends of the tubular portions I03.

A collar I09 surrounds the lower shaft 38 and is provided with an angular flange I01 connected to the lower flange I05 as by bolts I08, a sheet of asbestos or the like, as indicated at I09, being interposed between the flanges I05 and I01. A stuffing box or gland H0 is threaded upon the end of the collar-I06 and asbestos or other suitable material as indicated at III is compressed therein for the purpose of forming an air-tight seal around the shaft 38.

A similar-collar H2 is located around the shaft 31 and provided with an angular flange II3 having elongated vertical slots 4' therein through which are located the bolts I I5 which connect the flange I I3 to the upper flange I05, coil springs I I 6 being located around the bolts for normally pressing the flange II3 against the sheet of asbestos or the like located between the same and the flange I05 as indicated at II1. These slots H4 permit of vertical adjustment of the corresponding end of the shaft 31 by means of the adjusting screw 98.

A stufling box or gland H8 is threaded upon the end of the collar I I2 and asbestos or the like as indicated at I I9 is compressed therein to form a gas-tight joint around the shaft 31.

The shaft 40 is journaled in bearings I formed of suitable insulation material and provided with bushings I2I, the bearings I20 being mounted in uprights I22 supported upon the table 21. In the samemanner the shaft 39 is journaled in insulation bearings I23 having bushings I24, these hearings being located in the vertical slots I25 formed in the uprights I22.

- A coil spring I28 is interposed between the lower side of each bearing I23 and a socket I21 formed in the lower end of the slot I25, and a coil spring I 28 is interposed between the upper side of each bearing I23 and the adjusting screw I29 which extends into the socket I30 and is provided with a knob or wheel I3I for adjusting the tension upon the springs.

A casting or the like including a flat plate I32 is attached to eachside wall 29 of, the heating chamber as by means of bolts I33, a sheet of asbestos or the like, as shown at I34, being interposed between each plate I32 and the adjacent side wall. Each side wall 29 is provided with openings I35 of greater diameter than the shafts 39 and 40, through which openings the shafts are located, and each plate I32 is provided with tubular necks I36 arranged to register with said openings and having annular flanges I31 at their outerends.

The flange I38 of a collar I39, surrounding the upper shaft 39, is attached to the upper flange I31 so as to permit vertical movement of the collar I39 relative to the flange I31. A disk of asbestos or the like as shown at I40, and a disk of fiber or other suitable insulation material, as shown at I4I, are located between the flanges I31 and I33, insulation bushings I42 being located through suitable openings in the flanges I38 and the insulation disk I4I, said bushings being provided with vertical slots I43 through which are located bolts I44 which extend through the flange I31, coil springs I45 being interposed between each bushing and the head of each bolt in order to frictionally hold the flanges I3! and I33 together with the disks I40 and MI frictionally retained between said flanges.

A stufling box or gland I46 is threaded upon the end of the collar I39 and compresses therein asbestos or other suitable material as shown at I41 to provide a gas-tight joint around the shaft 39'. The lower shaft 40 is surrounded by a collar I48 having an annular flange I49 attached to the lower flange I31, disks I50 and I5I of fiber or other suitable insulation material and asbestos or the like respectively, being located between the flanges I31 and I49, bushings I52 of fiber or other suitable insulation material being located through suitable openings in the flange I49 and disk I50 and bolts I53 being located through said bushings and through the asbestos disk I5I and flange I 31 for connecting the parts together.

A stufling box or gland I54 is threaded upon the collar -I48 and compresses asbestos or like material, as indicated at I55, in order to produce a gas-tight joint around the shaft 40.

It will thus be seen that the upper roll 35 may be adjusted relative to the lower roll 36 to accommodate strips of various gauges and either end of the roll may be adjusted relative to theiother end thereof in order to produce greater tension upon one edge of the strip in order to anneal one edge of the strip softer than the other edge, in the same manner as described regarding the rolls 33 and 34, and one of the rolls 35 or 36 may have its surface slightly convexed or concaved if it is desired to anneal the edges or the central portion of the strip softer or harder as desired.

A valved outlet I56 may be provided in the top of the heating chamber, for use when hydrogen or other gas is being used in the furnace in order to indicate when the heating chamber is properly filled with the gas which may be burned'as it escapes from the outlet I56.

A plate I51 of brass or the like may be located between the rolls 34and 36 and inclined upward toward the latter to assist in guiding the strip between the rolls, said plate being supported by uprights I58 insulated from the table 21 as by the insulation blocks I59. Shoes I66 of brass or the like may be extended into the outlet neck I6I of the heating chamber to guide the strip therefrom and are insulated from the heating chamber. A window I62 may be provided in each side wall of the heating chamber, adjacent to the rolls 35 and 36'so that the operator can see the strip as it passes between the rolls and can judge the temperature thereof from the color of the strip.

Forthe purpose of passing current through the strip between the rolls 3334 and 3536,

. one roll of each pair is connected to an electric circuit. A cable or wire 163, leading from the positive side of the circuit, is connected to the A similar shoe I69 is held in contact with the shaft 40 by the springs I10 and the bus bars "I are clamped to said shoe as indicated at I12, thecable I13, connected to the negative side of the circuit, being attached to said bus bars. when a strip is passing through the heating chamber, the portion of the strip between the rolls, 33-34 and 35-36 becomesa conductor. completing the circuit between the rolls and the strip is heated up by the resistance of the current passing therethrough.

The cooling chamber is of considerably less cross sectional area than the heating chamber and is preferably formed of two tubular sections comprising the precooling chamber I14 and the final cooling chamber I15, the precooling chamber being of considerably less cross sectional area than the final cooling chamber. Insulationbushings are provided around the bolts to insulate the cooling chamber from the heating chamber. Y

The discharge neck l6l of the heating chamber may be provided at its end with an angular flange I16 and the adjacent end of the precooling chamber may be provided with a similar flange I11, the flanges being connected together as by bolts I18, a sheet of. asbestos or the like as indicated at'l19 being preferably clamped between the flanges.

A plate of brass or the like as indicated at I is preferably providedupon the bottom of the precooling chamber so that the strip, which is indicated at S throughout the drawings, will not be scratched as it is moved over the same.

Thus

For the purpose of heating the cooling chamber to the proper temperature, before the operation of the furnace is started, a gas'burner I8I may be located beneath the same. As soon as the furnace starts to operate, the hot strip passing from the heating chamber will maintain the a precooling chamber at suflicient temperature to permit the gas burner to be turned off.

For the purpose of producing blue annealed thereon, and the brass plate I80 being perforated I above the sump as shown in Fig. 1b, so that the water of condensation may drain through the 'same into the sump.

For the purpose of producing bright annealed strips, hydrogen or a mixture of hydrogen and nitrogen, or other suitable gas or combinations of gas, may be admitted through the pipe I85.

The adjacent ends of the precooling chamber and flnaLcooling chamber may be provided with flanges I86 adapted to be clamped together with 'a gasket I81 of asbestos or other suitable material located therebetween to provide a tight joint. Both the precooling and cooling chambers may be supported upon uprights I88. The final cooling chamber, as best shown in Fig. 4, may comprise the channel shaped trough I89 above which is spaced a second channelshaped trough I90 having a brass plate I9I in the bottom thereof over which the strip is adapted to be moved.

The top wall of the chamber I15 may comprise. a curved sheet or plate I92 tightly clamped upon the bottom portion'l89 as by the clamps I93. Water may beadmitted to the lower channel I89 through a pipe I94 located near the inlet end of the chamber I15 and may be discharged therefrom through a pipe I95 swiveled in the side of the'lower channel I89 near the discharge end of the chamber, said pipe I95 having an angular extension I95a to which a drain hose I96 may be connected. By rotating the pipe I95 I to raise or lower the angular extension I95a, the

'level of water in the channel I89 may be controlled. V

The discharge tube I91 extends downward at an angle from the end of the final cooling chamber, the adjacent ends of the discharge tube and cooling chamber being provided with flanges I98 clamped together with a gasket I99 of asbestos or the like interposed therebetween to produce a gas-tight seal. The lower end of the discharge tube extends into the quenching tank 200, below the level of the bath of oil or other quenching fluid therein and passes beneath the pulley 20I' and then upward between the blocks 202, the opposing surfaces of which may be provided with any suitable absorbent material as shown at 203 to wipe the oil or the like from the strip, which is then coiled upon the reel 204 mounted upon a frame 205 located beyond the quenching tank and driven at a speed corresponding to the speed of the rolls 33-34 and 3536.

For the purpose of driving the reel 294, a gear 286 may be fixed upon the shaft 201 of the reel and meshes with a pinion 208 upon the drive shaft 209 which may be driven by a motor or suitable source of power.

In the operation of the furnace, the gas burners 59 and "I may be lighted and the current is turned on to the cables I63 and Ill. The-motor 60 is started and the reel 2 is driven at the proper surface speed to correspond to the travel of the strip through the rolls in the heating chamber.

The strip is passed from the coil l2 through the wipers 23 over the. pulley I4 and under the pulley IS in the oil tank IS, the surplus oil being wiped iron" the strip as it passes between the wiping rolls 5| in the tube 48. The strip is then guided through the rollers 52 to the heating chamber andm itipasses between the rollers 33-34 and 35- it completes the circuit between the rolls 34 and 36, the strip being heated up by resistance. v

The operator, by looking at the strip though the window IE2 or Inc, can Judge the temperature of the strip by the color of the same and can control the temperature by the amount of current supplied to and tension placed upon the rolls. As the strip passes into the precooiing chamber I'll, it is cooled down quite rapidly and in actual practice may be cooled to about 100 degrees Fahrenheit before entering the final cooling chamber in which it is cooled down to substantially room temperature, after which it passes through the discharge tube I91 and quenching tank 200, the surplus oil being then wiped from the strip as it passes between the wiping blocks :02 prior to being coiled upon the reel 2.

The strip may be bright annealed by admitting hydrogen or other suitable gas or combinations of gases to the cooling chamber, or may be blue annealed by admitting steam to the cooling chamber. In order to assure sufllcient gas pressure throughout the entire furnace, the valves upon the valved outlets liiand H0, at opposite ends of the furnace, may be opened to-allow a small amount of the gas to escape and this gas may be ignited so that the operator will know that sufllcient gas is contained within the furnace as long as the flames continue to burn at these heating chamber, and a gas-tight cooling chamber of relatively great length and small. cross sectional area as compared with the heating chamber, two spaced pairs of metal rolls journaled through the walls of the heating chamber, one roll of each pair being located inone side of an electric circuit whereby a strip of metal passed through the furnace will be heated by resistance as it passes between said rolls and will be allowed to cool as it passes through the cooling chamber, and means providing insulated gas-tight bearings for said rolls.

2. An annealing furnace including a heating chamber, and a cooling chamber of relatively great length and 1 small cross sectional area as compared with the heating chamber, two spaced pairs of metal rolls iournaied through the walls of theheating chamber,oneroll ofeachpairbeing located in one side of an electric circuit whereby a strip of metal passed through the furnace will be heated by resistance as it passes between said rolls and will be allowed to cool as it passes through the cooling chamber, means providing insulated gas-tight bearingsfor the rolls, and means for sealing said chambers gas-tight.

3. An annealing furnace including a heating chamber, and a cooling chamber of relatively great length and small cross sectional area as compared with the heating chamber, two spaced pairs of metal rolls in the heating chamber, one roll of each pair being located in one side of'an electric circuit whereby a strip of metal passed through the furnace will be heated by resistance as is passes between said rolls and will be allowed to cool as it passes through the cooling chamber, means for sealing said chambers gas tight, and means for varying the tension upon said rolls without breaking said gas-tight seal.

4.-An annealing furnace including a heating chamber, and a cooling chamber of relatively great length and small cross sectional area as compared with the heating chamber, two spaced pairs of metal rolls in the heating chamber, one roll of each pair being located in one side of an electric circuit whereby a strip of metal passed through the furnace will be heated by resistance as it passes between said rolls and will be allowed to cool as it passes through the cooling chamber, and means for varying the tension upon opposite ends of said rolls to anneal one 'edge of the strip softer than the other edge thereof.

5. An annealing furnace including a heating chamber, and a cooling chamber of relatively great length and small cross sectional area as compared with the heating chamber, two spaced pairs of metal .rolls in. the heating chamber, one roll of each pair being located in one side of an electric circuit whereby a strip of metal. passed through the furnace will be heated by resistance as it passes between said rolls and will be allowed to cool as itpasses through the cooling chamber, and means for. varying the tension upon diflerent portions of the rolls to anneal certain portions of the strip softer than other portions thereof.

6. An annealing furnace including a gas-tight chamber, spaced pairs of rolls in the chamber, the necks of one roll of each pair extending through openings of greater diameter than the necks in the side walls of the chamber, angular flanges surrounding said openings, a collar journaled upon each of said necks and sealed thereon, an angular flange upon each collar having elongated slots therein, a sheet of asbestos or the like between each pair of flanges, bolts located through said first named flanges and through the slots in the second named flanges, springs upon said bolts, and adjustable bearings in which said necksare journaled.

HERBERT C. GREER. HERMAN C. CAPPEL. ROBERT W. SHOEMAKER.

ADOLPH FRIEDMAN. MILTON M. ROSE.

Images