US1324472A

US1324472A - Mechanical movement

Info

Publication number: US1324472A
Authority: US
Publication date: 1919-12-09
Anticipated expiration: 1936-12-09

Description

L. C. SHARP.

MECHANICAL MOVEMENT.

APPLICATION FILED JUNE 19. 1916.

1 24,472. Patented Dec. 9, 1919.

2 SHEETSSHEET 1- whim L. c. SHARP. MECHANICAL MOVEMENT.

Patented D60. 9,1919.

2 SHEETS SHEET 2- UNITED STATES PATENT OFFICE.

LEE C. SHARP, or PLATTSMOU'iH, NEBRASKA, AssICNoE. TO AMERICAN CAN COMPANY,

OF NEw YORK, N. Y., A CORPORATION or- NEW JERsEY.

MECHANICAL MOVEMENT.

Specification of Letters Patent.

Patented Dec. 9, 1919.

T 0 all whom it may concern:

Be it known that I, LEE C. SHARP, a citizen of the United States, residing at Plattsmouth, in the county of Cass and State of Nebraska, have invented certain new and useful Improvements in Mechanical Movements, of which the followingis a specification.

My invention relates to mechanical movements for changing or converting a continuous ornniform rotary motion to an intermittent or alternately accelerated and retarded rotary motion. It is the object of my invention to provide a power-transmitting mechanism in which the driven part may be caused to move either uniformly or intermittently or at a speed that varies harmonically, at the will of the operator; and

to provide in such a mechanism means by which the driving and driven parts are at all times positively gear-connected so that perfect synchronism may be maintained between them. My invention is especially useful in connection with mechanism wherein relatively heavy rotating parts are re quired to have an intermittent movement, so as to pause or move slowly at predeterminable intervals, and in such connection my mechanism takes the place of and provides a smoother, more certain and effective drivin action than pawl-and-ratchet devices, %reneva movements, and like mechanism heretofore used for this purpose, avoiding the use of brakes for checking the rapid phasesof the motion, and pickmg up the load from the slower phases without causing'jar or vibration.

In the accompanying drawings, Figure 1 is a side view of a mechanism embodying my invention, Fig. 2 isan end view of the same, Fig. 3 is an end view w1th the drlvepulley removed, showing the parts m a different position, Fig. 4 is a similar new with the parts at a still different position and adjusted to cause a pause or interruptlon of the movement of t is a similar view with the parts adjusted to cause uniform movement of the driven part,

Fig. 6 is a horizontal sectional view. on the irregular plane of the line a:w of Fig. 1 Fig. 7 is a side view of a modified forin o the mechanism, Fig. 8 is an end view of the same, Fig. 9 is a similar view of the same devices in a different position, Fig. 10 is an e driven part, Fig. 5.

end view of. another slightly modified form of the mechanism, Fig. 11v is an end view of another modified form of the mechanism, and ig. 12 is a side view of the same.

In each of the variously modified forms of the mechanism illustrated in the drawings, the driving or primarily-actuated part is a pulley 1 which is connected by a belt 2 with any suitable source of power from which it may bedriven continuously at a uniform rate. Also in each of the illustrated embodiments of the invention the driven or ultimately-actuated part is a horizontal shaft 3 which is shown as journaled in a suitable bearing-gtandard '4 mounted on a fixed bed or base The latter is considered to be a part of the machine upon which the mechanism is used, and of which parts immaterial to the present invention are broken away.

Referring particularly to the structure shown in Figs. 1 to 6, inclusive, the driven shaft 3 has secured thereon, adjoining the bearing 4, a large gear 6. On the portion of the shaft at the side of said gear opposite the bearing, there isiswin ably mounted a link or radius-arm 7 whic extends downwardly from the shaft, the lower portion being divided to provide 'two longitudinallyspaced bearings for a drive-shaft 8 which is thereby heldparallel with and at a fixed distance from the axis of the driven shaft 3. On the inner end of the shaft 8 there is secured a pinion 9 which mesheswith the gear 6', and on the outer end of said shaft 8 there is secured the drive-pulley l. 2 is extended in a direction substantially parallel with the radius-arm '7, so that said arm may be swung through a moderate angle about the axis of the shaft 3 without materially altering the tension of the belt. On the intermediate portion of the shaft 8, between the bearings therefor in the radius-arm, there is secured'an eccentric 10 which fits revolubly 'with the cocentric-strap 11, and extending from one side of said strap there is an integral arm or rod 12 having therein a longitudinal slot 13, as best shown in Fig. 5. A curved bracket-arm 14 is secured to the bed 5 and extends out laterallyadjacent to the slotted eccentric-rod 12, as shown. In the outer end of said bracket-arm there is fixedly held a pin 15 of which one end extends through the slot 13 so that the eccentric-rod rests The drive-belt slidably upon said pin. At one side of the eccentric-rod, near the end of the slot adjacent to the strap 11,there is a laterally extending stud 16 which is threaded and carries at its end a nut 17. On said stud between the nut and the side of the slotted rod 12, there is held a plate 18 having in one end an elongated opening or slot therein through which the stud passes. At the other end of. said plate the same has a cylindrical recess or notch therein adapted to fit around one side of the pin 15, and apart of the plate at one side of said notch extends beyond the same, forming a finger 19. At the side of the bracket 1 1 opposite the eccentric-rod the pin 15 has a nut 20 screwed thereon, and fitting slidably upon the pin between said nut and the side of the bracket there is a slotted rod 21 of which one end is pivotally connected with the radius-arm 7 as best shown in Fig. 6. The lengths of the slot in said rod 21, and of the slot 13 in the eccentriorod, are each equal to or slightly greater than the throw of the cocentric 16.

The operation of the described mechanism may now be understood. By loosening the nut 17 and permitting the plate 18 to hang from the stud 16 as shown in Fig. 5, the eccentric-rod 12 is permitted to slide freely upon the pin 15, so that during rotation of the drive-shaft 8 the eccentric may Work idly, merely causing a reciprocation of the -eccentric-rod together with a slight oscillation thereof about the pin 15. When the eccentric is set to work idly, the nut 20 is tightened down so as to hold the rod 21 in fixed relation to the bracket 14, and thereby prevent any swinging movement of the radius arm 7 about the axis of the shaft 3. When the parts are adjusted as described, the shaft rotates on a fixed axis,

the uniform rotational movement imparted to the pulley 1 by the belt 2 is transmitted through the shaft 8, pinion 9 and gear 6 to the shaft 3, and the latter 1s thereby driven also at a uniform speed.

To secure an intermittent or pulsating movement of the driven part, the nut 2 1s loosened to free the rod 21 and permlt swinging movement of the radius-arm 7, and the eccentric-rod is so connected with the p1n 15 that said rod may oscillate about the pm, but so that it may not slide thereon, or so that the sliding movement is limited to an amount less than the throw of the eccentr c. Said connection of the eccentric-rod and, pin 15 is effected by turning the plate 18 around into longitudinal alinement with the slot 13, so that the finger 19 rests on top of the pin 15 and the notch in the end of the plate fits around or against one side of the pin, and securing the plate in such position relatively to the rod by tightening down the nut 17. When the plate 18 is adjusted as shown in Fig. 3, at which no longitudinal move ment is permitted of the eccentric-rod relatively to the pin 15, the radius-arm is caused to oscillate about the axis of the shaft 3 so that the axis of the shaft 8 moves a distance equal to the throw of the eccentric at each revolution thereof. During such oscillatory movement the pinion 9 remains in mesh with the gear 6 but the rate at which the gear is driven, instead of being uniform, is modified so that'it increases and decreases harmonically. During the half-revolution of the shaft 8 in which the arm 7 swings in the direction opposite to that in which the gear is being driven, the pinion rolls planetarily, upon the gear anamount equal to the amount of the swinging movement, so

that the actual movement communicated to the gear by the pinion during any interval is only the excess, if any, in the peripheral. movement of the pinion over the simultaneous movement of its axis in the opposite direction. During the alternate half-revolutions of the shaft 8, the movement communicated to the gear by the peripheral movement of the pinion has added thereto the amount of the swinging movement, the rate of movement of the driven part being thus accelerated proportionally to the retardation occurring during the swinging of the radius-arm in the direction first-named. Thus the total movement of the driven part caused during a complete revolution of the shaft 8 is the same as when the axis of said shaft is stationary. The amount of retardation and acceleration of movement of the driven part is determined by the throw of the eccentric, and, by suitably proportioning the same, a complete stop or cessation of the movement of said driven part may be caused to occur at the moment of greatest retardation. Should'the throw of the eccentric be made greater than necessary to cause momentary cessation of movement of the driven part, the motion of said part will be actually reversed during a period greater or less according to the excess in the throw of the eccentric over the amount first stated. If it is desired that the driven part shall stop for a period of definite duration, instead of momentarily, thethrow of the eccentric is made great enough to cause a reversal of movement of the driven part as above explained, but the plate 18 is set at a position such as shown in Fig. 4, so as to permit a slight longitudinal movement of the eccentric-rod relatively to the pin 15. Then, instead of the movement of th driven part being reversed, the eccentric-rod will move longitudinally during the corresponding portion ofthe cycle, and the driven part will remain stationary during such eriod.

Referring now to the modified form of the mechanism, shown in Figs. 7 8 and 9, the

rod 21, for connecting the radius-arm with the pin 15, is omitted, and the eccentric-rod is merely connected pivotally with said pin, the rod not being slotted, and the plate 18 being omitted. The drive-pulley 1, instead of being secured on the shaft 8, is revolubly mounted on an extended portion of the shaft 3, and a driving connection is established between said pulley and the shaft 8 by means of a pinion 22 and gear 23, the latter being secured on the shaft 8 and the former being secured to the pulley and revoluble on the shaft 3. In this arrangement of the mechanism, the axis of the drive-pulley remains stationary, and the movement of the driven part is pulsatin or retarded and accelerated substantially as before described, the movement being very slightly modified by the planetary rolling of the gear 23 about the pinion 22, but such modification not changing the essential character of the derived movement.

In the modification of the mechanism shown in Fig. 10 the drive-pulley 1 is secured on the shaft 8, and the eccentric-rod is both slidably and pivotally connected with the pin 15, the .plate 18 being omitted, however, as in the structure shown in Figs. 7, 8 and 9. The action of this form of the mechanism will be obvious from the foregoing In the modification of the mechanism shown in Figs. 11 and 12, the swinging movement of the radius-arm is not harmonic in character, as it is when derived from the rotation of an eccentric. Instead of the eccentric there is employed a groove-cam 24, and the pin 15, or a roller revolubly mounted on said pin, extends into the groove of the cam, as shown. In the cam shown, the groove is concentric with the shaft for slightly more than half the circumference, and dips inwardly between the ends of the concentric portions. With a cam of this form, the radius-arm is held stationary and the movement of the driven part is uniform during that part of the cycle in which the pin is engaged in the concentric portion of the cam groove, and the swinging movement of the radius-arm, with the resultant slowing and acceleration of the driven part, occurs only during the time that the pin is traversing the dipped portion of the camgroove. It will be obvious that by the use of suitably formed cams, various modifica- 'tions of the derived movement may be efi'ected, the form of cam shown being merely illustrative of thisgeneral manner of modifying the mechanism.

I claim:

1. In a powentransmitting mechanism, a driven shaft. a driving shaft disposed parallel therewith, a radiusarm pivotally connecting said shafts and oscillatable to swing one of said shafts about the axis of the other, constantly-meshing gears secured on said .a fixed point of attachment for shafts, and means actuated by one of the shafts to oscillate said radius-arm in synchronism with the rotation of said shaft.

2. In a power-transmitting mechanism, a driven shaft, a radius-arm pivoted thereon, a driving shaft journaled in the radius-arm parallel with the driven. shaft, means for rotating the driving shaft uniformly, constantly-meshing gears secured on said shafts and operatively connecting the same, an eccentric secured on the driving shaft, an eccentric-strap and rod' connected with said eccentric, a stationary pin, means for connecting the eccentric-rod to said pin slidably and pivotally, and means for connecting the radius-arm fixedly to said pin.

3. In a power-transmitting mechanism, a driven shaft, a fixed bearing therefor, an arm mounted to oscillate about the axis of said shaft, a driving shaft journaled in said arm and held thereby at a uniform distance from the driven shaft, gears operatively connecting said shafts, an eccentric secured on the driving shaft, and means connecting the eccentric with a fixed part, whereby the driviIig shaft and the arm in which it is journaled are oscillated about the axis of the dfilgnf shaft during rotation of the driving s a 4. In a power transmitting mechanism the combination of a driving element rotatable at a constant speed, a rotatable driven element, and a pinion connected with the driving element and having a periodic planetary movement about the axis of said driven element to vary the speed transmitted from said driving to said driven element, and means for periodically interrupting the planetary movement of said pinion.

5. In a power-transmitting mechanism, a driven shaft, a driving shaft parallel therewith, a radius-arm pivotally connecting said shafts and oscillatable to swing one of said shafts aboutthe axis of the other, constantly meshing gears secured on said shafts, an eccentric and strap mounted on one of said shafts, and a slotted adjustable controlling means connecting said strip with a fixed pomt. i y

6. In a power transmitting mechanism, a

driving and a driven element rotatably connected, the driving element havin planetary movement relative to' said driven element, to impart to said driven element periods of retardation and acceleration without altering the ratio of travel of the said driving and driven elements during a complete cycle, and means comprising a link having controlling said planetary movement.

7 In a power transmitting mechanism, a driving and a driven element positively rotatively connected, and adjustable means whereby said driving element may be given planetary as well as rotative motion, thus imparting to said driven element variable phases of retardation and acceleration Without changing the ratio of travel of the said driving and driven elements during a c0mplete cycle.

8. In a power mechanism a driving and a periodically during a complete cycle but not changing said speed ratio for a complete cycle.

9. In a power mechanism a driving and a driven element positively rotatably connected to have under normal conditions of operation fixed ratios of constant rotative speeds, and means connected with said driving element whereby said driving element may be given a multiplicity of variable planetary movements relative to said driven element, thus varying the speed ratio of said elements periodically during a complete cycle but not changing said speed ratio for a complete cycle.

10. In a povver transmitting mechanism a driving and a driven element positively rotatably connected to have under normal conditions of operation fixed ratios of constant rotative speeds, and adjustable means controlling said driving element and adjustable therewith to impart to said driven element a range of motion extending from a constant uniform rotative motion to successive periods of retardationjextending to complete cessation of rotative motion, thereby imparting tosaid driven element a multiplicity of variable speed ratios during a complete revolution'of said driven member but not altering the speed ratio between said driving and said driven element for a complete revolution.

Signed in the presence of a subscribing Witness.

LEE C. SHARP.

Witness y D. O. BARNELL.