US2269290A - Speed-change mechanism - Google Patents

Description

Jan. 6, 1942.

G. H. SCHURGER SPEED-CHANGE MECHANISM 3 Sheets-Sheet 1 Filed Feb. 26, 1940 fzaeizz or I Garize 13v r27. 6072 age v r W fi o/we s.

1942- G. H. SCHURGER 2,269,290

SPEED-CHANGE MECHANISM Filed Feb. 26, 1940 3 Sheets-Sheet 2 //////////fl/////////////////////////////////////////WV/// Rue/ a or Gar/zen]? Gck uger 15 G. H. SCHURGER SPEED-CHANGE mmcmmrgm' 3 Sheets-Sheet 3 Filed Feb. 26, 1940 Patented Jan. 6, 1942 UNITED STATES PATENT OFFICE SPEED-CHANGE MECHANISM Garner H. Schurger, Fond du Lac, Wis., assignor to Giddings & Lewis Machine Tool 00., Fond du Lac Application February 26, 1940, Serial No. 320,805

2 Claims.

The present invention relates to improvements in speed-change mechanisms, adapted particularly for machine tools. In general, the present invention consistes an improvement upon the mechanism disclosed in Keith F. Gallimore Patent No. 2,106,731, issued February 1, 1938.

One object of the present invention is to provide a speed-change mechanism having a simplified and inexpensive adjusting mechanism of novel form. In a large measure, this simplification is accomplished by utilizing cooperating cam parts fixed directly on and rigid with, respectively, a set of intermittent gears in the actuator and a corresponding set of shifter shoes, which engage the shiftable gear elements of the speedchange gearing. By this means I have eliminated the relatively expensive and complicated lever and rock shaft connections heretofore used in connecting such gear and shifter shoe elements as shown, for example, in the Gallimore patent referred to above.

Another object is to provide a speed-change mechanism embodying a novel form of cranktype adjusting means whose manipulation is materially simplified by virtue of the fact that a full revolution of the hand crank is used for each successive speed setting, thereby also simplifying the apparatus as a whole through the elimination of the detents or the like otherwise necessary to define the successive fractional revolution positions of the hand crank.

The invention also resides in various structural improvements and innovations, by means of which simple and effectual operation are combined with low cost and ruggedness of construction.

Further objects and advantages of the invention will become apparent as the following description proceeds, taken in connection with the accompanying drawings, in which:

Figure 1 is a fragmentary front elevation of a tool head containing a speed-change gearing embodying the present invention.

Fig. 2 is an enlarged horizontal sectional view along the line 2-2 in Fig. 1.

Fig. 3 is a vertical sectional view along the line 3-3 in Fig. 2.

Fig. 4 is a general perspective view of the gearing.

Fig. 5 is a detail view of the intermittent gears included in the speed-change actuator.

Fig. 6 is an enlarged outer face view of the actuator shoes.

Fig. 7 is a detail view, partially in section, of

the dial mechanism for the speed-change gearing.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the drawings, the speed-change mechanism may beinterposed in any desired drive, as, for example, in an axial feed spindle drive, such as that disclosed in the copending application of Keith F. Gallimore, Serial No. 320,853, filed February 26, 1940, and may, in its broadest aspects, be adaptedto afford any desired number of selected speeds.

In the present instance the mechanism as illustrated as affording eighteen different speed settings. For this purpose it includes (see Fig. 4) series connected nine and two-speed gearings, designated generally as l0 and H, respectively, the nine-speed gearing comprising in effect two three-speed gearings. These gearings may be enclosed in a suitable casing I2 (Fig. 1) which has been shown herein as a portion of a headstock or movable tool head.

The nine-speed gearing l0 includes (Fig. 4 and see also Fig. 2) an inlet shaft I3, an outlet shaft I4, and an intermediate shaft l5, all of said shafts being suitably journaled in the casing l2. The inlet shaft I3 is adapted to be connected toa suitable source of power, as, for example, to an electric motor l6 (Fig. 1) through suitable intermediate connections (not shown). is, on the other hand, connected to the two-speed gearing II and the latter is in turn connected to feed a tool spindle (not shown) in the tool head casing I2.

On the nine-speed unit inlet shaft l3 (Fig. 4) are loosely journaled two end gears I1 and I8 adapted to be alternatively coupled to the shaft l3 by a centrally located clutch sleeve I9 axially splined on the shaft. This clutch sleeve has on its ends external clutch elements 20 positioned for alternative engagement with complemental internal clutch elements 2| fashioned in the inner faces of the end gears l1 and I8. Integral with the sleeve I9 is athird gear 22. Meshing with the end gears I1 and I8 are end gears 23 and 24 fast on the intermediate shaft I5 while a third or central gear 25, also fast on this inter- The outlet shaft l-l mediate shaft, is arranged to mesh with the gear 22 when the clutch sleeve I9 is in its intermediate position as shown. The clutch sleeve IS, with its gear 22, thus constitutes a shiftable clutch unit having three different operative positions of adjustment. First, if the sleeve I9 is in its intermediate position, as shown, the inlet shaft I3 is connected to the intermediate shaft I5 through the meshing gears 22 and 25. Second, when the sleeve I9 is shifted to the left to couple the gear H to the inlet shaft I3, this latter shaft is connected to the intermediate shaft through gears I1 and 23. Third, when the clutch sleeve is shifted to the right to engage the corresponding clutch elements the shafts |3 and I5 are connected through the gears l8 and 24. These various gear combinations have different speed ratios so that the intermediate shaft |5 may be driven selectively at any one of three different speeds.

Similarly, on the nine-speed unit outlet shaft M are loosely journaled two end gears 26 and 21, adapted to be alternatively coupled to the shaft by a centrally located clutch sleeve 28 axially splined on the shaft M. This clutch sleeve has external end clutch elements 29 alternatively engageable with complemental internal clutch elements 30 on the respective end gears 26 and 21. Additionally, a third or central gear 3| is fixed on the sleeve 28 and is adapted to mesh with the central gear 25 on the intermediate shaft |5 when the sleeve 28 is in its central or vertical position. The end gears 26 and 21 mesh with gears 32 and 33 fixed to the gears23 and 24, respectively, ingly, when the clutch sleeve 28 is in its central position shown the gears to complete a drive from l5 to the outlet shaft M.

the intermediate shaft On the other hand when the sleeve 28 is shifted to the left to couple the gear 26 to the shaft N, the drive from the shaft |5 to shaft I4 is completed through gears 32 and 26. Similarly, coupling of the gear 21 to the shaft H by the sleeve 28 completes a drive connection between the shafts I5 and I4 through gears 33 and 21. As before, the ratios between the three alternatively available pairs of gears are different so as to afford three different speed ratios between the shafts l5 and I4.

By adjusting each of IS and 28 successively into positions of progressively different speed ratios, and adjusting one unit, for example, the unit l9, through all of its positions for each position of the other unit, the outlet shaft sively different speeds.

The two-speed gearing (Figs. 2 and 4) is connected to the nine-speed outlet shaft I4 and includes its own outlet shaft 34. On the shaft I4 is fixed a pinion 35 meshing with a gear 36 fast on a shaft 31. Also fast on this shaft 31 is a pinion 38 meshing with gear 39 splined on the outlet shaft 34. Rigid with this latter gear 39 is an internal end clutch element 40 positioned to engage a compleniental external clutch element 4|, fixed on the pinion 35, when the gear and clutch unit 39-40 is shifted to the left. It will thus be seen that a high speed connection may be completed directly between the shafts l4 and 34 through the clutch elements 4|, 40 or alternatively a low speed connection may be completed between these shafts through the pairs of elements 35, 36 and 38, 39.

In order to shift the clutch units i9 and 28 of the nine-speed gearing, two shifters 42 and of the intermediate shaft. Accord.-

25 and 3| are in mesh the clutch units or sleeves l4 maybe driven at nine progresi so that the crank pins 55 and 56 43 are utilized (Fig. 4). These shifters include arcuate shoe portions 44 and 45 respectively dimensioned to engage the lateral sides of the corresponding gear elements 22 and 3| of. the respective clutch units. The lower shifter 42 is mounted for rectilinear sliding movement, along a path paralleling that of the inlet shaft |3, by

a pair of vertically spaced guide rods 46, while the upper shifter 43 is similarly mounted for rectilinear movement by a. pair of guide rods 41. As the shifters 42 and 43 are moved along the guide rods the associated clutch units are moved correspondingly to their three successive positions of adjustment described above.

For the sake of maximum simplicity and compactness of construction, cooperating cam parts are fixed directly on and rigid with the shifters 42, 43 and a corresponding pair of intermittent gears 48 and 49 (Fig. 5) which are utilized in actuating these shifters. The lower gear 48, which is the driving gear of the pair, has a toothed sector 50 extending through 120 degrees and adapted to mesh successively with three similar toothed sectors 5|, 52 and 53 on the gear 49.

. Abutments 54 between the toothed sectors 5|,

52 and 53 on the gear 49 are movable selectively into engagement with the untoothed portion of the gear 48 to lock the gear 49 in fixed position during the two-thirds of each revolution of the gear 48 in which its toothed sector 50 is out of engagement with the gear 49. Thus the gear 49 is advanced onehird of a revolution for each full revolution of the cooperating intermittent gear 48 and is locked in position during the periods of dwell between its successive actuations.

In the cam means for connecting the shifters 42, 43 with the gears 48, 43, crank pins 55 and 56 are fixed to the inner faces of the respective gears (Figs. 2' and 5). The pin 55 is located diametrically opposite the tooth sector 50 while the pin 56 is located on the radial center line of one of the abutments 54. The intermittent gears 48, 49 are located directly opposite the outer faces of the shifters 42 and 43, respectively, project into corresponding vertical cam grooves 51 and 58 fashioned in the outer faces of the shifters (see Figs. 2, 4 and 6). Consequently, as the intermittent gear 48 is rotated in a clockwise direction the pin 55 will occupy the three successive positions designated as A, B and C in Fig. 6, thereby moving the shifter 42 to its three successive corresponding positions for the clutch unit is. Similarly, as the second intermittent gear 49 moves in a counterclockwise direction its crank pin 56 occupies successively the positions designated as D, E, and F in Fig. 6 to move the shifter 43 to its corresponding three positions for the other clutch unit 28.

To prevent overtravel of the shifter 42 as the pin 55 moves between positions A and B a recess 51 is fashioned in the side of the vertical cam groove 51 and to prevent overtravel in the opposite direction a similar recess 51 is formed at the right hand side of the cam groove (Fig. 6).

Corresponding recesses 58 and 58 in the sides of the cam groove 58 in the upper shifter 43 prevent overtravel of this shifter in the same manner.

To rotate the first intermittent gear 48, and thereby move the other gear 49 and the shifters 42 and 43 in timed relation, a hand crank 59 is provided on the front of the casing l2 (Figs. 1 and 2). This hand crank is fixed on the forward end of a rotatably iournaled shaft 60 having axially shiftable gear 39 (see also Fig. 4).

fixed on it a pinion 6|. This pinion meshes with a gear 62 (see also Fig. 3) fast on a shaft 63, to the inner end of which is fixed the first intermittent gear 48. The ratio between the pinion 6| and gear 62 is one to three so that for each full revolution of the hand crank 58.the intermittent gear 48 will be moved through one-third of a revolution. In other words, each full revolution of the-hand crank 58 shifts the crank pin 65 on the gear 48 through 120 degrees so that the engaged shifter 42 is advanced one step in its series of three steps or positions for setting the gear unit IS. The second or driven intermittent gear 49 is in turn loosely journaled on the inner end of a shaft 64 (Fig. 2) located above the shaft 63 (see Fig. 3) and is', of course, driven from the first intermittent gear 48. Thus nine successive full revolutions of the hand crank 69 will move the shiftable clutch units l8 and 28 of the nine-speed gearing to their nine successive settings. Since a full revolution of the hand crank is used for each step in the setting, the device is very simple to manipulate and no detents or the like are required to define fractional revolution settings for the hand crank.

In the case of the two-speed gearing ii, an adjacent'hand crank 65 is provided on the front of the casing l2 for changing its setting (Fig. 1). This hand crank is fixed on the forward end of a shaft 66 (Fig. 2) suitably journaled in the casing and carrying on its inner end an eccentrically located crank pin 61 (see also Fig. 3). This crank pin is received in a longitudinal slot 68 fashioned in the lower arm of a bell crank 69 pivoted at 10. On the outer end of the upper bell crank arm is fixed a second crank pin 1| received in a complemental slot 12 in a shifter 13. This shifter is supported for rectilinear sliding movement on a pair of horizontal guide rods 14 and embodies an arcuate shoe 15 embracing the In the position shown in Figs. 2, 3 and 4 the gear 39 is positioned to mesh with the gear'38 for the low speed setting of the two-speed gearing ll'. Upon oscillating the hand crank 65 in a clockwise direction from the position of Fig. 1 to that of Fig. '1, the bell crank 69 is oscillated counterclockwise and the shifter 13 is moved to the left, thereby pulling the gear 38 out of mesh with the gear 38 and engaging the clutch elements 48, 4| to complete the high speed connection for the two-speed gearing and in which the shafts l4 and 34 are directly coupled. To restore the gearing to its low speed setting the hand crank is, of course, oscillated in the opposite direction to its initial position.

A simplified and improved form of visual indicator means has been provided for showing at all times the composite setting of the nine and two-speed gearings I8 and II. For this purpose, an open face dial 16 (Figs. 1, 2 and '1) is fixed to a sleeve 11 on the shaft 64. This sleeve is, in turn pinned to a gear 18 meshing with a pinion 18 fixed on the shaft 63 (Fig. 3). The ratio of the pinion 19 to the gear 18 is one to three so that for each full revolution of the hand crank 59 the dial 16 will be advanced one-ninth of a revolution. On the face of the dial 16 are eighteen indicia 80 arranged in pairs and in a circular series. Upon each advance of one-ninth of a revolution for the dial 16 a corresponding pair of these indicia 86 will be presented to a pointer 8|.

In the present instance the indicia 80 (see Fig. 7) show spindle feed rates in terms of inches per revolution. Each of the indicia contains two figures to show the corresponding feed speeds for two spindles, as for example a main spindle and an auxiliary spindle in the machine, and which are adapted to be fed through the medium of single drive including the speed-change gearings Ill. and II. The outer circle of figures (made up of the outermost figures in each of the indicia 80)' shows the feed rates for one spindle and the inner circle those for the other spindle. Thus the operator can easily, and simultaneous- 1y, read the feed rate-.setting for both spindles from the selected one of the indicia 86.

The pointer 8| is shifted in accordance with the setting of the two-speed gearing ll so as to indicate which of the two indicia 80 presented by the dial 16 should be read by the operator. For this purpose the pointer 8| is fixed on an axially movable slider 82 which is yieldably urged to the left (Fig. '1) by a compression spring 83. Projecting from the shaft 66 which carries the hand crank 65 is a pin 84 arranged to engage an abutment 85 on the slider 82. When the hand crank 65 is positioned for the high speed setting of the two-speed gearing (as shown in Fig. 7), the pin 84 engages the abutment 85 and thrusts the slider to the right so that the pointer 8| registers with the right hand one of the indicia present at the bottom of the dial 16. Similarly, when the hand crank 65 is shifted to its low speed position (shown in Fig. 1) the pin 84 is oscillated away from the abutment 85 so that the spring 83 moves the slider endwise to bring the pointer 8| into registry with the other of the presented pair of indicia 80.

From the foregoing it will be seen that a speed-change mechanism has been provided which is characterized particularly by its compactness and small number of parts despite the very wide variety of speed settings afiorded. Moreover, the manipulation of the mechanism by the two hand cranks 59 and 65 is very simple, particularly in view of the use of a full revolution of the hand crank 58 for each step in setting the nine-speed unit.

I claim as my invention:

1. A speed-change mechanism comprising, in combination, a speed-change gearing having two selectively shiftable-gear elements movable in adjacent parallel paths, individual shifter shoes engaged with respective ones of said elements, means slidably supporting said shoes for rectilinear movement in paths paralleling the paths of movement of said elements, each of said shoes having three positions in its path'of movement for corresponding settings of the speed-change gearing, said shoes presenting outer faces disposed side by side with cam grooves therein, disposed at right angles to the direction of shoe movement, a first intermittent gear having three gear sectors extending through 129 degrees, a second intermittent gear having a single gear sector extending through degrees for selective meshing engagement 'with the first mentioned sectors to rotate said first gear through one-third of a revolution for each complete revolution of said second gear, said gears being arranged opposite corresponding ones of said shoes and each having an eccentrically located crank pin thereon projecting into the cam groove in the corresponding shoe, and means for rotating said second gear.

2. A speed-change mechanism comprising, in combination, a speed-change gearing having two said elements and selectively shiftable gear elements, individual shifter shoes engaged with respective ones of single gear sector extending through 120 degrees for selective meshing engagement with the first mentioned sectors to rotate said first gear through one-third of a revolution ior each complete revolution of said second gear, means for disposed for movement alterconnecting said gears in operative relation with respective ones of said shoes to shift the corresponding shoe to a different one of its three positions for each one-third of a revolution for its associated gear, a hand crank fixed on said third shaft, means forming a one-to-three gear connection between said second and third shafts to rotate said second intermittent gear one-third of a revolution for each full revolution of the hand crank, an indicator dial on said first shaft, and means forming a one-to-three gear connection between said second shaft and said dial to rotate the latter through one-ninth of a revolution for each full revolution of the hand crank.

GARNER H. SCHURGER.

Images