US1312091A - Automatic reversing mechanism - Google Patents

Description

W. ARTER.

AUTOMATIC REVERSING MECHANISM. APPLICATION FILED MAY 8. 1916. 1,312,091 Patented Aug. 5, 1919.

3 SHEETS-SHEET I.

Wwvmq Tm: COLUMBIA PLANOURAPN c0., WAsHlNdTON, D. C.

W. ARTER.

AUTOMATIC REVERSING MECHANISM.

APPLICATION FILED MAY 8,-1916.

Patented Aug. 5, 1919.

3 SHEETS-SHEET 3 UNITED STATES PATENT OFFICE.-

WILLIAM ARTER, 0E WORCESTER, MASSACHUSETTS, ASSIGNOR To THE PERSONS- ARTER MACHINE COMPANY, or WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

AUTOMATIC REVEBSING MECHANISM.

Specification of Letters Patent.

Patented Aug. 5, 1919.

Application filed May a, 1916. Serial a... 96,101.

like reference characters on the drawings indicating like parts in the several figures.

This invention relates to automatic reversing mechanisms, such for-instance as those employed in grinding and planing machines, and other machine tools. The invention has for its chief object to devise a mechanism of this character, which shall be more reliable and positive in action than similardevices now in use, and shall also be more convenient to operate and less liable to get out of order.

The invention will be readily, understood from the following description, reference being made to the accompanying drawings, in which- 1 Figure 1 is a view in front elevation of a reversing mechanism embodying the invention in the form now preferred by me; i i

Fig. 2 is a central, vertical, cross sectional view of the mechanism shown in Fig. 1, and

Fig. 3 is an angular view showing the more important parts of this mechanism on a somewhat larger, scale.

Referring now to the drawings, 2 indicates the frame or bed of a machine, such for instance as a grinder or planer, provided on its upper face with horizontal ways on which slides a table 4 that is designed to carry the work, or a grinding or other operating tool. This table is reciprocated on its ways to subject diiferentportions of the work to the operation of the grinding or other tool. For this purpose a rack 6 is secured rigidly to the bottom of the table extending parallel to the Ways on which the table slides, and a pinion 8 meshes with this rack and is mounted on the upper end of a vertical shaft 10suppo'rted insuitable bearings in the frame 2. Mounted on the shaft 10 is a toothed clutch sleeve 12 keyed to the shaft but slidable longitudinally thereof into or outof engagement with a similar toothed sleeve 14 that rotates loosely on the shaft 10 and forms the hub of riphery.

" gears 30 and 31.

a worm wheel 16. In order to move the sleeve 12 into or out of engagement withits cooperating sleeve 14, a collar 18 is formed on the sleeve 12 and is grooved to receive a pair of rolls 19 and 20 mounted on the forked end of a lever 22 which is fulcrumed on the machine frame at 23. The forward end of this lever is positioned within convenient reach of the operator.

The worm'wheel 16 is driven by a worm 2 f which is fast on one end of a shaft 25 mounted to rotate in along bearing formed in one part of a gear casing 26 that is bolted to the side of the machine frame 2. A large bevel gear 27 is mounted on the forward end 'ofthe shaft"25"and within the casing 26.

The main driving shaft 28 of the machine is mounted in bearings formed in the casing 26 and has secured thereto a series of pulleys 29 by means of which the machine may be belt connected to any convenient source of power. Within the casing 26 the shaft 28 supports two bevel gears 30 and 31, respectively, which are arranged to mesh with the bevel gear 27 at opposite points in its pe- Both of these gears 30 and 31 are loose on the shaft 28 and the adjacent ends of their hubs are toothed. A sleeve 32, mounted on the shaft 28 between the gears 30 and 31, and splined to said shaft but slidable'thereon, has its opposite ends shaped to mesh with the teeth on the respective Accordingly, when this sleeve is moved into engagement with either one of the bevel gears 30 or 31, it will cause the gearso engaged to rotate with the shaft 28 and this rotative motion will be transmitted to the bevel gear 27 and throughthe haft 25, worm 24 worm wheel 16, the clutch members 12 and 14 (assuming them to be in engagement) shaft 10, pinion 8 and rack 6, to'the table 4. The direction of this motion will depend on which of the gears 30 or 31 is driving the bevel gear 27. n

For the purpose of controlling the engagementofthe clutch sleeve 32 with one or theother of its cooperating gears 30 and this leeve is grooved toreceive amember forming part ofa shoe 34 whichis pinned to a rod 36 lying above and parallel with the shaft 28 and is arranged to reciprocate longitudinally in bearings formed in the easing 26. This rod 36 has pinned to it at opdirection or. the other to effect a driving engagement between the clutch sleeve 32 and one of the gears 30 or 31, it is locked in that position by one member of a pair of pawls 40 and 41, pivoted, respectively, near the opposite ends of the rod 36, the pawl 40' being arranged to engage, with the collar 1 38, and the pawl 41 with the collar 39. Two springs 42 and 43 connected to the respective pawls 40 and 41 serve to retain them yieldmgly in locking engagement w th thelr res ective collars.

, he pawls 40 and 41 may be released from locking engagement with their respective collars by means of a lever fulcrumed on the upper part of the casing 26 and having a handle that projects above the level of the work table 4 and a part projecting below the fulcrum and carrying a pin 46 that lies between the adjacent ends of the pawls 40 and 41. The ends of these pawls lie close to each other and are curved upwardly, as shown clearly in Figs. 1 and 3, so that, when the pin 46 is swung into engagement with either pawl, it will lift it out of engagement with its coiiperating stop collar 38 or 39.

' Pivoted to the rear face of the lever 44, and just below the fulcrum of said lever, are two arms indicated at 48 and 49, which bow out away from each other, then curve inwardly and downwardly toward each other again, terminating in ends that lie on opposite. sides of a lug 50 that projects rearwardly from the shoe 34. The pin 46 extends through the end of the lever 44 and the portion of the pin 46 that projects from the back of the lever 44 also lies between the ends of the arms 48 and 49 and just above the lug 50. Two tension springs 52 and 53, each having one end connected to a pin 51 secured in the lever 44 just below its fulcrum point, and having their other ends connected, respectively, to the arms 48 and 49, tend to keep the free ends of these arms in contact with the pin 46 and the lug 50.

The lever 44 may be moved by hand in either direction necessary to shift the clutch sleeve 32 from either of its operative positions to the other, or, mother words, into engagement with either of the clutch memers formed on the hubs of the gears 30 and 31. Ordinarily, however, this movement of the lever 44 is effected automatically by means of dogs 56 and 57 arranged to engage with a pin 58 projecting from the back of the lever 44, and both mounted for adjustment longitudinally of a rack 59, which is secured rigidlyto thetable 4.

The mechanism so far described is similar to that shown and described in the pending appllcation of Alphonso White, S. N. 1146,

filed Jan. 8, 1915, and assigned to the assignee of the present invention.

The operation of the mechanism so far described is as follows:

The main shaft 28, of course, is always driven in one direction. lVhen the parts are in the positions in which they are shown in Fig. 1 the table 4 is moving from left to right, the beveled pinion 30 being operative at this time to drive the gear 27. hen the dog 56 strikes the pin 58, as the table 4 continues to travel toward the right, it will move the upper end of the lever 44 toward the right, thus swinging the pins'51 and 46 on the lower end of the lever 44 toward the left (as seen in Fig. 1). This movement distorts or tensions the spring 52, since the arm .48 to which it is connected tends to follow the pin 46 but is prevented from doing so by its engagementw-ith the lug 50 on the shoe .34, the shoe being held against movement at this time by the pawl 41. As soon, however, as the pin 46 has been swung far enough to the left to strike the forward curved end of the pawl 41 it will lift this pawl, thus unlocking the shoe 34 and permitting the spring 52, which has been distorted or tensioned by the movement of the lever 44 to throw the shoe toward the left and move the clutch 32 out of engagement with the gear 30 and into engagement with the gear 31. The latter gear then becomes operative to drive the gear 27 and the shaft 25 in a direction opposite to that in which they have just been rotating and consequently to reverse the direction of travel of the table 4. The dog 57 next will engage the pin 58 and operate through the lever 44, and the connections; controlled thereby, to shift the parts back into the positions in which they are shown in Fig. 1, This shifting of the clutch sleeve 32 from one of its operative positions to the other, and the consequent reversal of the direction of movement of the table 4, will continue until the shaft 28 is stopped or until the reversing mechanism is stopped in a neutral position.

It sometimes happens that one of the springs 52 or 53 fails to shift the clutch member 32, as above described, due to some unusual resistance to the movement of the parts. When this occurs there is, of course, much danger that some of the parts of the mechanism will be broken. The present invention, therefore, provides an arrangement by which a positive shifting movement is imparted to the clutch sleeve in case it sticks. For this purpose the shoe 34, which shifts the clutch member 32 is provided with two lugs-6O and 61, which lie close to the curved end portions of the pawls 40 and 41, as clearly shown in the drawings. These lugs are so located with reference to the path of movement of the pin 46 that the pin strikes one or the other of these lugs, depending of course on its direction of movement, immediately after it has lifted the'corresponding pawl 40 or 41 far enough to unlock the shoe 34. Consequently, if at any time either spring 52 or 53, which has just been tensioned by the lever 44 preparatory to shifting the shoe 34 and the clutch sleeve 32, is unable to initiate the shiftin movement when the shoe has been unlocke the pin 46 immediately becomes effective by its engagement with one or the other of the lugs 60 or 61 to impart a positive movement to the shoe 34 in a direction aiding the spring 52 or 53 which is, at this particular time, tending also to effect this shifting movement. Since the pin 46 is operated 'by power, it positively initiates the shifting movement of the clutch sleeve 32; and one or the other of the springs 52 or 53 then completes the movement so initiated. If one of the springs 52 or 53 should break, and thus become inoperative, the pin 46 would positively move the sleeve32, through the connections just described, into its neutral position and thus stop the movement of the table 4. I

It is sometimes diflicult to stop the reversing mechanism in its neutral position and in order to facilitate this operation a manually operated stop is provided. This stop consists of a short shaft 62 (see Figs. 2 and 3) rotatably mounted in the cover of the casing 26, and provided in front of said cover with a handle 63, and in the rear of said cover with a stop piece 64. Two lugs 66 and 67 respectively, project forward from the shoe 34 (as clearly shown in Fig. 3). The handle 63 and the stop 64 project in the same direction so that when the handle is turned either up or down the stop 64 will not lie in the path of movement of either of the lugs 66 or 67 but when this handle is moved into a horizontal position the stop 64 then will lie in the path of travel of one or the other of these lugs. If the lever 44 is then swung to shift the sleeve 32 in a direction tending to move the lug toward which the stop points into contact with the stop 64, this member will arrest the shoe 34 and consequently the clutch sleeve 32 in its neutral position. This stop mechanism affords a very convenient means for stopping the movement of the table 4 whenever desired.

While the invention has been herein disclosed as embodied in the form now preferred by me, it is obvious that it is not limited to embodiment in this specific form, but that many changes may be made in the details of construction without departing from the spirit or scope of this invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A mechanism of the character described, comprisin a driving shaft, a driven member mounted or movement in either of two directions, and a reversing mechanism connecting said shaft and member, said mechanism comprising a device shiftable from one operative position to another to effect a reversal of the movement of said member, spring means Operative normally to shift said device from one of said positions to another, and positively acting means operative to initiate the shifting movement of said device. a

- 2. A mechanism of the character described, comprising a driving shaft, a driven member mounted for movement in either of 'two directions, and a reversing mechanism connecting said shaft and member, said mechanism comprising a device shiftable from one, operative position to another to effect'a reversal of the movement of said member, spring means arranged to shift said device from either of its operative positions tothe other, means for locking said device in either of said positions, and power operated means operative to distort said spring means preparatory to effecting said shifting movement and acting thereafter to unlock said device and positively move it.

3. A mechanism of the character described, comprising a driving shaft, a driven shaft, and a reversing mechanism between said shafts arranged to drive the driven shaft from said driving shaft in either direction, said mechanism comprising a device shiftable on said driving shaft fromone operative position to another, means for locking said device in either of its operative positions, a lever, spring means through which said lever is operative to shift said device yieldingly from either of its operative positions to the other, means for transmitting from said lever to said device a positive shifting movement aiding said spring means, and means operated by said driven shaft for giving said lever its operative movement.

4. In a machine of the character described, the combination with a driving shaft and a reciprocatory table, of a pair of gears driven by said shaft, connections between said gears and said table enabling them to drive the table in opposite directions, a clutch member movable from one operative positive to another to render either of said gears effective to drive said table, a pair of pawls cooperating with said clutch member to hold it in either of its operative positions, a lever arranged to be moved by said table, spring means arranged to be distorted by the movement of said lever and tending to shift said clutch member from either of its operative positions to the other, and means operated by said lever to unlock either of said pawls and thereafter to positively move said clutch member.

5. A mechanism of the character described, comprising a driving shaft, a driven member mounted for movement in either of two directions, and a reversingmechanism connecting said shaft and member, said mechanism comprising a device shift'able from one operative position to another to effeet a reversal of the movement of said member, means for yieldingly effecting a shifting movement of said device, and a stop movable into and out. of the path of movement of said device and operative, when in said path to arrest the shifting movement of said device when the device reaches its neutral position.

6, In a machine of the, character do: scribed, the combination with a driving shaft and a I'eciprocatory table, of a pair of gears driven by said shaft, connections between said gears and said table enabling them to drive the table in opposite directions, a clutch member movable from one operative position to another to render either of said gears effective to driie said table, a pair of pawls cooperating with said clutch member to hold it in either of its operative positions, a lever arranged to be moved by said table, spring means arranged to be distorted by the movement of said lever and tending to shift said clutch member from either of its operative positions to the other, and a manually operated stop mounted for movement into and out of the path of movement of a part movable with said clutch member and operative when in said path to arrest the "shifting movement, of said clutch member them to drive the table in opposite directions, a clutch device mounted for mov e ment into either of two positions in which it is operative to render one or the other of said gears effective to drive said table, means for locking said device temporarily in either of its operative positions, a pair of movable arms operative to move the device from one position to another, a lever arranged to be-oscillated by said table, and springs connecting said lever to each of said arms and operating through said arms to tension independently each of said springs in one direction and thereafter to release the locking means to permit the springs to move said device from either of its operative positions to the other.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

RUFUS B, Donor, WM, J. TAI'I.

Ooplu of thin pltcnt may be obtained for in cents each, by addressing the Commissioner of Patents. Washington, 1)., ca"

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