US1305050A - be all - Google Patents

Description

F. F. BEALL. GEAR MANUFACTURE.

APPLICATION FILED DEC. 23 1914.

Patented May 27,1919.

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Patented May 27, 1919.

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F. FLBEALL. GEAR MANUFACTURE. APPLICATION FILED DEC.23, 1914 Patented May 27, 1919.

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iii STATES iZPENT @i FlltlFi.

FRANK F. BEALL, OF DETROIT, MICHIGAN, ASSIGNOR TO liACKAlRD MOTOR CAR COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

GEAR MANUFACTURE.

Application filed December 23. 1914.

To all whom 2'2. may concern:

Be it known that l, FRANK F. BEALL, a citizen of the United States, and resident of Detroit, Wayne county, State of Michigan, have invented certain new and useful 1m provements in 'Gear Manufacture. of which the following is a specification.

This invention relates to gear manufacture, and particularly to bevel or other crown gear wheels and their manufacture.

The invention comprises a method of forging or pressing gears-into shape as dis tinguished from cutting or casting them. Gear cutting is an expensive operation and cast gears are not suitable for many purposes. One of the objects of the present invention is to produce gears of hard metal such as steel and at much less cost than cut gears.

Other objects will appear from the following description taken in connection with the drawings, in which Figure 1 is a part elevation and part section of a gear blank in the form in which it leaves the drop hammer;

Fig. 2 is a similar View of the blank after leaving the roughing die;

Fig. 3 is a similar view 'of'the blank after leaving the finishing die and before the excess metal has been removed;

Fig. 4 is a similar view of the finished gear;

,Fig. 5 is a plan view of half of a finished gear like that shown in Fig. 4;

Fig. 6 is a fragmentary enlarged end elevation of several of the teeth of the finished gear showing in dotted lines the contours of the teeth in various stages of completion; I

Fig. is an enlarged sectional view of the finished gear showing in dotted lines the contours of a tooth in various stages of completion;

v Fig". 8 is an elevation of a drop forge hammer of the type used for roughing out the gear blank shown in Fig. 1;

Fig. 9 is an elevation of a press adapted for carrying out one of the pressing operations of the invention:

, Fi i0. is a ress similar to that shown in Fig. Q s adapted tor carrying out Specification of Letters Patent.

Patented May 2'2, 191%.

Serial No. 878.733.

another of the pressing operations of the invention Fig. 11 IS a fragmentary section through i the roughing die showing it in operating relation with the gear blank:

Fig. 12 is an end view of the die and blank shown in Fig. 11;

Fig. 13 a View similar to Fig. 11 showing the finishing die;

Fig. 14 is an end view of the die and blank shown in Fig. 13;

Fig. 15 is an elevation and part sectional view through a grinding machine for performing certain grinding operations on the gear;

Fig. 16 is an enlarged vertical section through one of the die presses showing the biank in position; i

Fig. 17 is a plan view or horizontal section on the line 17-47 of Fig. 16;

Fig. 18 is an enlarged side view of a part of one of the die presses showing the locating lever in position;

Fig. 19 is an enlarged perspective view of the locating lever; and

Fig. 20 is a transverse section through the head of the locating lever.

This invention. involves die pressing a blank to form teeth by displacing the metal of the blank with space forming (lie parts so that metal extends beyond the normal limits, as the tops, for instance, of the teeth. and then removing the excess, as by grinding or i'nachining. The blank may be so supported that some excess metal will be pressed outwardly at the ends of the teeth, and this eXc ss metal may likewise be removed.

The invention also involves die pressing a blank having teeth oi abnormal proportions so that the teeth are pressed into the desired shape. As illustrated herein. a blank having teeth of abnormal thickness is die pressed so that the sides of the teeth are compressed to the desired face contour. The abnormally thick teeth may be formed by forging or die pressing with a roughing die.

in the form of the invention particuiarly set forth herein, a. gear Hank having a plain face is drop forged, is then placed in a die press where a roughing die forms of abnormal thickness and preferably of less height than the required finished tooth, is then subjected to a second die pressing operation in which a finishing die compresses the thick teeth to the desired contour and forces excess metal outwardly beyond the normal topsand perhaps at the ends of the teeth, and is then machined or ground to remove the excess metal. The last step is the hardening of the finished gear. Gears made by this method will be found in most cases to be accurate enough for the finest work, but if desired a finishing cut may be made on the faces of the teeth before hardening to give a still greater degree of accuracy. -A gear made'in accordance with the above referred to method is shown herein and comprises teeth the faces of which are compressed and-die finished leaving the metal denser at'and adjacent said faces, and the tops andfiends of which have a cut finish where, the excess metal has been removed either by achining or grinding.

Referring to the drawings, B represents generally a gear blank and in Fig. 1 it is a plain blank 30 having a web portion 31 and a portion 32 in which the gear teeth are to be formed. In Fig. 2 the blank B is shown as having teeth 33 which are thick relative to the spaces between them and not as high as the teeth of the finished gear should be.

As shown the teeth and spaces have no sharp corners it thereby being possible to form such a blank either by a quick rough pressing process or by drop forging. As shown' I also, the teeth are arranged in a. generallydiagonal direction and are curved lengthwise, but other desired forms'of teeth may be made. 3

In Fig. 3 the gear blank B is shown as having its teeth 33 formed with correct faces 34 but an excess of metal extends above the normal tops of the teeth as shown at 35, the dotted line 35 representing the normal top of one of the teeth. Some of the excess metal has also been pressed outwardly at the ends of the teeth as at 36 and 37. Aside from the excess metal above referred to, the teeth of the gear shown in Fig. 3 are perfectly formed and would be ready for use.

In Figs..4 and 5 the gear blank B has.

become a finished ear 38, the excess metal above referred to having been entirely removed either by machining or grinding, thus leaving a cut finish at the tops and on the ends of the teeth. In Fi 6 and 7 enlarged views of gear teeth are s own, 35, 36 and 37 representing in dotted lines the excess metal,

that has been removed, and these views illustrate the clean sharp edges that are obtained by thus pressing the teeth and subsequently removing the excess metal. lnthese figures also the dotted line 39 traces an outline of the teeth 33 of the gear shown in Fig. 2 as it cranes from the roughing die,

. the teeth,

Figs. 8 to 20 inclusive, illustrate a method of and suitable machinery for making gears like that above described.- By this method, with some metals and with some sizes of gears the various forging and pressing steps maybe carried out with one heating of the blank. For this purpose a suitable drop hammer 40 and two presses or similar machines 41 and 42 should be grouped to ether so that the gear blank may first be orged at its greatest heat by the drop hammer 40, then transferred immediately to the press 41 where it receives the roughening operation and then placed in the press 42 to be pressed under the finishingdie. Under certain circumstances, however, it may be desirable to mer as shown and the dies 43 and 44 are shaped to produce the blank 30shownin- Fig. 1. The die block 43 is the stationary die and the die 44 is reciprocated' toward and from the die 43 by the piston rod 45 and its piston operating in the steam cylinder 46.

The presses 41 and 42 shown in Figs. 9 and '10 are identical except in the forms of their up )er dies. In each, 47 represents the lower or stationary die resting on the table 48, and 49 is the press ram or support for the upper or movable die. The ram is operated by hydraulic pressure through a piston in thecylinder 50.

The press 41 has the roughing die 51 secured to its ram, and as the he moves downwardly its space forming parts 52 press into the blank B as shown in Figs. 11 and 12, forming thick aud comparatively low teeth as shown in Figs. 12 and 2, and in dotted lines in Fig. 6. The press 42 has the finish ing die 53 secured to its ram, and as this die descends upon the blank that has been trans-' ferred from the press 41 the abnormally thick teeth are compressed between the space forming parts 54 of this die as shown in Figs. 13 and 14, thus condensing the metal along the tooth faces and forming a gear like that shown in Fig. 3.

there is a. slight excess of allowed to flow metal which is beyond the normal tops of as shown at 35 in Fig. 6, and outwardly to a lirnited extent at-the ends of the teeth, as at 36 and 37 in Fig. 7.

From the press 42 the ear or blank is transferred to a machine f or removing the excess metal from the tops and endsof the 'toethI Such a machine is shown in Fig. 15.

In this operation The gear is secured to a rotating table 55 and grinding wheels 56, 57 and 58 are properly set to cut away the excess metal, thus leavin the gear teeth of perfect form and with c ean cut edges, as shown in Figs. i to 'i' and 15.

Ordinarily the gear thus completed will be suliiciently accurate for use, but if desired a machining or grinding process may be carried out on the faces of the teeth before it is case hardened. Case hardening gives the desired wearing qualities to the faces of the teeth and is particularly efficient when combined with the compressing of the gear teeth as herein described.

More particularly referring to the presses, attention is called to the further showing in Figs. 16 to 20 inclusive. The gear blank B is shown in position in the depression 59 in the die block 47. The latter is formed with a central bore 60 to receive a centering stud,

' a little beyond normal and later removed, as

hereinabove described. The spaces 63 between the projections 62 provide clearance for the outer ends of the space forming parts 54 of the die 53 as the die descends vertically to form. the gear.

in addition to the pilot 61 extending from the upper die 53, the latter is providedwith a presser plate 6% which has a series of bolts 65 forming a sliding connection between the die andthe plate. Springs 66 surround the bolts 65 and tend to press the plate downwardly away from the die, this movement being limited by the heads of the bolts striking the shoulders 67 in the bores 68 in which the bolts operate. This presser plate 64 follows the pilot 61 in contacting with the blank during the descent of the ram and the springs hold the blank yieldingl-y in the depression 59 in position to beacted upon by the die 53. The plate like the die 47, is formed at its edgewith a series of projections 69 for supporting the inner ends of the teeth of the gear during the pressing opera tion', and the spaces 70 between the projections 69 provide for die clearance thesame as spaces 63.

Means are provided for accurately locating or positioning the blank circumferentially before the upper die is brought down on the blank, as when the blank receives a roughing operation in one press or by one die and a second or finishing operation in a' second press or by another die. After one die has started the formation of tooth spaces in the blank it is necessary that the blank should be properly located under the second die so that the space forming parts of the second die will accurately enter the "spaces already roughly formed in the blank. In the present invention this circumferential positioning is done by a locating lever 71 which may be pivoted as shown to the. sta tionary die block 47 at 72. The head 73 of this lever has a groove in one of its operating faces and a tooth on the opposite face and in the form shown the groove H is in its upper face and is adapted to receive one of the teeth or space forming parts 54 of the die 53, and the tooth is in its lower face and is adapted to engage in one of the spaces between the teeth of the roughed out blank.

The lever 71 is shown in full lines in Fig. 16 in inoperative position and in dotted lines in operative position for locating the blank in proper circumferential relation to the die 53. Fig. 17 shows the lever inoperative and Fig. 18 shows how it lines up the teeth and spaces of the die and blank respectively. In operation, the blank is roughly positioned by hand with the tooth 75 of the locating lever in one of the, tooth spaces of the blank. The ram is then brought down slowly until one of the die teeth enters the groove 74: and thereby definitely and accurately locates the blank under the presser plate. Then the ram is raised suiliciently to permit the lever 71 to be removed and then brought down.

forthe pressing operation.

The lever 71 may be manually operated by a 'pivotally connected hand" lever 7 6 mounted on the die block 47 as by a link 77 and bracket 78. A spring 79 retracts the hand lever 76 and keeps the lever 71 normally in theinoperative position shown in full lines in Fig. 16.

More particularly .eferring to the machine shown in Fig. 15, it will be seen that it comprises a base 80 upon which is suitably mounted the rotating table 55 operated by a pair of gears 81 82, and a belt and pulley 83. Standards 84, 85 and 86 adjustably support the three brackets 87 in which are respectively mounted the grinding wheels 56, 57, and 58, hereinabove referred to. The brackets 87 are manually adjustable vertically as by hand wheeiddandserswand nut connection shown in dotted lines 'at 69. 1\ frame 90 supports shafting 91 for dri ving the three grinding wheels as through bolts 92' and gears shown in dotted lines at 93. Suitable belt tighteners 94L keep the belts tight as the grinding wheels are adjusted (liming the operation of the machine. Thus it will be seen that by a single operation the excess metal is removed from the tops and ends of the gear teeth and the gear given an 'accu- 1 rate and clean finish.

not limited to the specific gear, method and machine herein shown and described, but is capable of modification in various ways Without departing from the scope of the claims.

Having thus described my invention, What I claim and desire to secure by Letters Patent is 1. The method of making gears consisting of die pressing a blank to form teeth press the sides of the teeth to the desired face contour and causing excess metal to flow beyondthe normal tops of the teeth, and then removing such eXcess metal.

3. The method of making gears consisting ,Of forming a blank with teeth of abnormal thickness, then die pressing to compress the sides of the teeth to the desired face contour, and causing excess metal to extend beyond the tops of the teeth, then removing such excess metal, and then case hardening the gear.

4,. The method of making gears consisting in forging the blank, then die pressing the blank to form teeth having thedesired face contour with the excess metal pressed out- Wardlv beyond the normal tops of the teeth, and then removing such excess metal.

5. The method of making gears consisting in forging the blank, then die pressing the blank to form teeth of abnormal thickness and of less height than required in the finished gear, then subjecting the blank to a second die pressing which compresses the sides of the teeth to the desired face contour While permitting the excess metal to flow beyond the normal ends and tops of the teeth, and then removing such excess metal.

6. The method of making gears. consisting in die-pressing the blank to form teeth of abnormal thickness and of less height than required in the finished gear, then die-press ing to compress the sides of the teeth to the desired face contour While permitting the excess metal to flow beyond the normal tops of the teeth, and then removing the excess metal.

in the presence of two Witnesses.

v FRANK F.. BEALL.

Witnesses: a

I LE R01 J. WILLIAMS,

CLAIR J. Corn.

In testimony whereof I afiix my signature

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