US1386329A - Mechanism for converting rotary into reciprocatory motion - Google Patents

Description

R. GOLDSCHMIDT. MECHANISM FOR CONVERTING ROTARY INTO RECIPROCATORY MOTION.

APPLICATION FILED JAN 10. I321. 1,386,329. Patented Aug. 2, 1921.

4 SHEETS-SHEET R. GOLDSCHMIDT.

MECHANISM v OR CONVERTING ROTARY INTO RECIPROCA TORY MOTION.

APPLICATION FILED JAN. 10. 1921.

1,386 329, Patented Aug. 2, 1921.

4 SHEETSSHEET 2.

R. GOLDSCHMIDT. MECHANISM FOR CONVERTING ROTARY INTO RECIPROOATORY MOTION.

APPLICATION FILED JAN.10,19ZI. 1,386,829, Patented Aug. 2, 1921.

4 SHEETSSHEET 3- Fla /0 R. GOLDSCHIVHDT.

MECHANISM FOR CONVERTING ROTARY INTO RECIPROCAIORY MOTION. APPLICATION FILED IAN. 10, I92I.

1,886,829. Patented Aug. 2, 1921.

4 SHEETS SHEET 4.

is a'specification.

UNITED STATES PATENT OFFICE.

mmonr Gonoscnum'r, or 13mm, GERMANY, ASSIGNOR ro nn'r TExmsx ronsoesax'rmsmsxan, or cmnorrmrnunn, DENMARK, A. COMP OF DENMARK. I

MECHANISM FOR CONVERTING ROTARY INTO RECIPROCATORY MOTION.

Specification of Letters Patent.

Patented Aug. 2, 1921.

Application filed January 10, 1921. Serial 110.4%,206.

To all whom it may concern:

Be it known that I, RUnoLr GOLDSCH MIDT, a German citizen, residing at 45, Linden Allee, West End Berlin, Germany, have invented new and useful Improvements in Mechanism for Converting Rotary into Beciprocatory Motion, of which the following This invention relates to mechanism for converting rotary into reciprocatory motion and more particularly for imparting to' the" reciprocatory member a continued translatory or progressive movement step by step in one direction of the path of reciprocatlon.

This translation or progressive movement may be utilized for example for imparting progressive movement to the reciprocating tup of a drop hammer or the like, thus automatically feeding the tup nearer to the work as required." The translatory or progressive motion may also be utilized in connection with the fiapping wings of ornithopters or like flying machines in.which the wings,

- in addition to a flapping or "reciprocatiory motion, have progressive forward motion in' 7 common with the whole flying machine.

According to the present invention; a reciprocatory member, is reciprocated by a rotating centrifugal weight or weights pivoted to the reciprocatory member, and a undirectional impulse is impressed upon the reciprocatory member at the end of each complete vibration of the member, so that it travels or rogresses step-by-step in one direction. his impulse can be impressed I upon the member, for example by a buffer which is undirectionally progressed so that the reciprocatorv member is adapted to abut against. the buffer before it completes each vibration.

In order that the invention may bemore clearly understood reference is hereinafter made to the accompanying drawings, whereon:-

Figure 1 is a diagrammatic view of a'simple form of the mechanism for straight line motion.

. Fig. 2' is a view similar to Fig. 1 showing Fig. 5 illustrates dia rammatically the reciprocatory member 0 Fig. 1 abutting against one of the buffers.

F1 6 1s a view corresponding to Fig. 5 showing the buffers displaced so as to impartprogresslve movement to the reciprocatory member in one direction.

F ig. is a'sectional view of the improved mechanism applied to a reciprocatory tool or chisel.

Fig'. 8is a sectional view at right angles to Fig. 7 showing the centrifugal weights and driving gear.

Fig. 9 is a diagram illustrating the reciprocatory member of Fig. 7 in its emf posispring or springs on the reciprocatory mem ber.

Fig. 14 illustrates diagrammatically a further modification in which the spring is moilipted in the bufier or reciprocated tool itse Referring to Fig. 1 of the drawings,the ,bodya represents the reciprocatory member which may be the top of a reciprocated tool or any I equivalent reciprocatory element, illustrated as being guided in a strai ht line by means of guides f, Rotatable at out an axis 0 on the body a is an arm 8 fitted with a weight 0.

If the arm .9 is rotated, the resulting centrifugal force R accelerates 0r retards the motion of the body a which is set in reciprocation by a force H equal to R.cos.a. If B represents the weight of the mass 0, Z the distance of the center of the mass 0 from the axis 0, A the weight of the body a and 2 the unrestricted travel of the body a, then If B were equal to A, thenxa would equal Z.

In any case, 2 is quite independent of the angular velocity of the arm s, provided that the friction and other power expended is small compared with the change of energy I the physical law that the center of inertia in the masses. The motion is dependent on I created equal to R sin. a. This may be obviated if two equal centrifugal weights 0- and 0 are fitted as in Fig. 2 to rotate in o arm 8 may be e posite directions, the centrifugal forces and R giving a resultant effective force H.

The arm 8 may be driven in any desired manner, either by belt or cord drive or by a flexible shaft either wholly flexible or fitted with universal joint at its ends and telescopically movable in the direction of reciprocation. Alternately, the power may be transmitted to the rotary arm '8 by means of square shafts and gearing slidable thereon or like means, the shaft being disposed parallel to the ath of oscillation. 'Or the Feotrically driven.

The rotating masses have a balancing action on the system, balancing the accelerating and retarding forces of the reciprocating masses and counter-acting any sudden change in velocity.

The foregoing mechanism produces reciprocator motion as illustrated by the curve in 3.

The unrestricted travel 2 of the body a, due to the action of the centrifugal forces of the masses 0 is dependent on the length of the arm a and the proportions of the masses, and also on the friction and useful work done if these are considerable. The path of reciprocation is thus determined in cngthz, but its position in space can only be determined by buffers or the like such as d or e. If the. distance de is somewhat shorter than the unrestricted travel a, the difference may be absorbed resiliently by springs either at d or e or upon the body a. If the buffers d e are adjusted, the position of z will be varied. A very small force will generally suffice to effect this movement. In Fig. 5, the body a is diagrammatically, shown in its end position on the left, when it just abuts against the buffer d. a If now the buffer 03 is moved a distance m (Fig. 6) into the position d and the buffer 6 into the position e while the body a moves between d and e the body a will strike correspondingly earlier against the buffer d at a considerable velocity and will thereby receive, through the springs or by impact, a greater impulse than thebody a received at e the impulse being equal to the force multiplied by the time during which it acts. The increased impulse thu created at the left, will urge the path offreciprocation toward the right until the body on again assumes a stable path of reciprocation within the new limits al 6 If, however, the oscillating body is not al-' lowed to become stable within the limits al e but is impressed with a constant impulse in one direction, the system will travel progressively in that direction and produce the reciprocating and progressive movement illustrated by the curve in Fig. 4.

In the case of a vertically reciprocating body, the gravitation of the body will in itself tend to produce progressive movement.

Such progressive reciprocatory motion may be adapted to apparatus whose movement is of a progressive oscillatory character and wherein resistance to movement differs in two succeeding amplitudes of vibration of the apparatus. 7 v

In nearly all practical cases, only..the progressive component of the compound motion constitutes useful movement. cating component is in nearly all cases'only a kind of auxiliary motion.

Such is the case with a flying machine having flapping wings, wherein the wings move upwardly and downwardly and at the same time, have movement in common with the whole flying machine and wherein the air resistance during the down stroke isgreater than during the upward movement of the wing.

In the case of a power-driven vertically reciprocated hammer, the impulse due to resistance to movement on the down stroke 18 also considerably greaterand takes place at the end of the stroke on impact. But as, at this moment, theblow is transformed into work, the progressive movement is generally only very slight at the end of each downstroke, although'the force of the blow may be considerable.

In the mechanism described with reference to Figs. 1 to 6 an impulse is impressed upon the reciprocatory member by a buffer or buffers against which the reciprocatory member abuts before it completes its amplitude of vibration in one or other direction. The buffers preferably consist of springs ad ustable along the path of reciprocation and the.

reciprocatory member s acted upon by the spring buffer or buffers only during a fraction of its travel.

In order to avoid shocks 0r vibrations in the reciprocatory member during its travel, it may be desirable to provide a' spring or springs adapted to act upon the rec1procatory member during the whole-of its travel. The spring or springs are preferably normally under stra1n,e1ther in tension or compression, so that further extenslon or compression of the spring will not materially affect the force exertedv bythe spring on the reciprocatory member.

Although in some cases it may be sufli- The reciprocient to provide a spring on one side only of the reciprocatory body, a spring may, if desired, be fitted at each side of the reciprocatory body so as to more efiiciently control the latter.

Figs. 7 and 8 illustrate the application of a single spring a reciprocatory hand tool adapted to be supported by a handle 43 fixed to a casing 44. The reciprocatory tup 45 has lugs 46 supporting a driving spindle 47 driven by a coil spring 48 from a flexible shaft 49 and motor 50. The spindle 47 carries a spur wheel 51 driving. a spur wheel 52 on a parallel spindle 53. The spindles 47 and 53 are each fitted with eccentric weights 54, the centrifugal action of which causes reciprocation of the tup 45. A spring 55 is fitted between a collar 56 on the tup 45 and a collar 57 on the casing 44. The

of the tup tup 45 is adapted to strike against a tool 58 which may be a chisel, riveting hammer or the like. A

In'this case part of the energy stored in the tup 45 is transformed by the blow of the tool into useful work and the down, stroke is most effective when the whole of the energy is transformed. The return stroke of the tup 45 compresses the spring and thus stores up energy in the spring, which is ven up during the working stroke and serves to accelerate the latter. Variation of the pressure of the spring '55 or of the pressure of the tool 58 against the work by the operator, or variation of the angular velocity of the eccentric weights 54 will affect the reciprocation of the tup 45. As soon as the pressure of the tool 58 against the work drops below a certain value or the angular velocity of the eccentric weights 54 increases above a certain value the number of revolutions of the weights 54 per unit of time will be greater than the number of blowsimparted by the tup 45 until only one blow takes place for ever two or three revolutions of the weight 5 If the pressure on the tool is increased above a certain value, the tool will receive a blow for each revolution of the weight 54, but the latter will describe a greater or less dead angle 158 (as in Fig. 9), that is to say, the weight 54 will describe a-certain angle before its centrifugal force resolves itself into v a vertical component which is capable of lifting the tup 45 and overcoming the force of the spring55.

The, spring 55 is preferably normally 'under considerable compression so as to reduce the vibrations transmitted to the casing 44.

In order to protect the centrifugal weights 54 and driving mechanism from shocks during the stroke of the tup 45 a spring 59 may be fitted between a' tug 61 and a recigjrocated member 60 as in. ig.12.

ig. 13 illustrates a modification in which a tup 62 is formed with a collar 63 supporting springs 64 adapted to bear against the tool 65 on the downstroke of the tup 62.

Fi 14 illustrates a further modification in. w ich a tup-66 strikes against a spring buffer 67 on the end of the tool, anvil or the like 68.

The constructions according to Figs. 12, 13 and 14 are particularly applicable to heavy tools, such as forging hammers or pile drivers, in which case the weight of the reciprocated member or tup is equivalent to a downwardly-acting spring of constant pressure. The force of the blow will be partially stored up by the springs 59 or 64 of Figs. 16 and 17 or the spring buffer 67 of Fig. 18 and accelerate the return stroke of the tup. This will be more readily understood if one considers the tup at rest when the centrifugal action of the centrifugal weight or weights will lift the tup with an initial velocity to a certain height. After the downstroke the energy stored up during the blow will increase the return velocity of the tu so that it will be lifted to a greater height and the force of the next blow will be correspondingly increased, thus giving .a graduated increase in the height to which the tup rises, until a maximum height is reached, which will depend on the ratio of the initial velocity to the added velocity due to the reaction. In such case the spring or springs absorbing a part of the blow and giving it up on the return stroke, may actually be constituted by the block of steel or other body operated upon.

Fig. 10 illustrates the application of the invention to a pile. A casing 69 is mounted on the pile-driver7O and a bottom plate 71 in the casing 69 is interposed between the pile and the tup 72 so that the tup strikes the pile through the medium of the plate 71. A ring 73 surrounds the upper end of the pile to prevent fracture thereof and is inclosed by an annular extension 74 and di-. vided flange 75 which serve to hold the casing 69 in position on the driver. The tup is formed with journals supporting a cross pin and 79. The weights are shown integral with crown teeth meshing with bevel pin ions and 81 mounted on stub shafts 82 and 83 projecting from the cross pin 76 loosely carrying eccentric weights 77, 78 i 76. The pinion 80 is driven by a splined.

shaft 84 which is capable of sliding through a hollow shaft 85-di'iven from the motor 86 through a coil spring 87. By this arrangement it will be seen that the pinions 80 and 81 reciprocate with the tup 72 and that the weight 78 will revolve in the opposite directlon'to the weights 77 and 79 so that if the weight 78 is, equal to the combined weights of 77 and 79, it will counterbalance the horizontal forces created by the weights 7? and 79. In this construction, the tup car- 'threaded'to engage a corresponding thread 91 in the casing 69. The crown of the ring .90 is formed with teeth 92 engaged by a* pinion 93 rotatable from the exterior by means of asquared shaft 94 projecting .through a vertical slot in the casing 69. The

compression of the spring 89 can thus be .varied'by the turning the squared shaft 94.

Fig. 11 illustrates the application of the invention to a forging hammer. In this case the mechanism is mounted on a fixed frame or standard 95 having a bracket 96 which supports the motor 97 driving a splined shaft 98 through a coil spring 99. Slidable on the splined shaft 98 is a bevel pinion 100 journal'ed in a cross pin 101. The pinion 100 meshes with teeth on an eccentric weight 102 loosely rotatable on the cross pin101. The latter is supported by lugs 103 above the tup 104 which carries a disk 105. The tup 104 is guided by collars 106 and 107 which areexternally 1n threaded engagement with an internally screwed boss 108 supported from the standard 95. The collars 106 and 107 also form abutments for springs 109 and 110 respectively and are fitted with 'hand wheels 1111 and 112 for enabling the springs 110 and 111 to be adjusted in relation to the disk 105. In the position of adjustment illustrated on the drawings, the spring engages the disk 105, while the spring 109 remains out of action. The anvil is represented by 113 supporting the work piece 114. If the distance b between the work piece 114 and the highest position of the tup 104 is less thanthe distance a between the disk 105 and spring 109, the disk 105 will not abut against the spring 109, but by adjusting the hand wheel 111 the distance a can be varied until the sprin 109 is brought more or less into action. Similarly the spring 110 may be lifted by the adjustment of the hand wheel 112 until the tup ceases to strike.

against the work piece 114. This enables the work piece to be removed, exchanged or .replaced while the forging hammer continues to reciprocate.

It will be noted in Figs. 7, 10, and 11 that a coil spring is interposed between the motor and the centrifugal weights. This is in order to produce more or less uniformity in the reciprocations, by absorbin the fluctuations of the motor and preventing shocks being.

transmitted from the reciprocating tup to. the motor shaft, especially when the centrifugal weights describe the dead angle 158 referred to with reference to Fig. 9; When the centrifugal weight is describing this dead angle, the angular. velocity of the weight is somewhat decreased owing to the sudden arrestment of the reciprocating tup and. it is important that this sudden variaf tion of the angular velocity of the weight trifugal weights. i

Claims:

1. Mechanism for converting rotary 1nto reciprocatory motion, wherein continued progressive movement step-by'step in one direction of the path of reciprocation is obtained, comprising a .reciprocatory member, a centrifugal weight pivoted thereto, means for rotating said weight and means for impressing a unidirectional impulse upon the reciprocatory member, so that it travels or progresses step-by-step in one direction.

2. Mechanism accordin to claim 1 having an additional centrif'uga weight of equal centrifugal arm length pivoted to thereciprocatory member and means for rotating the two weights in opposite directions.

.3. Mechanism according to claim 1 in which the means for impressing a unidirectional impulse upon the reciprocatory member'comprises a buffer which may be unidirectionally progressed along the path of reciprocation.

4. Mechanism for obtaining continued progressive reciprocatory motion step-bystep in one direction from rotary motion comprising a reciprocatory member,-a centrifugal weight pivoted thereto, means for rotating said weight and a spring adapted spring will not materially affect the force exerted by the spring on the member.

6. In. a reciprocatory tool, atup, mechanism for reciprocating the tup comprising a centrifugal weight. pivotally mounted on the tup, means for rotating said weight and means for impressing a unidirectional impulse upon the tup at the end of each complete vibration thereof.

7 ,A reciprocatory tool as specified in claim 6 having a plurality of rotatable cenv trifugal weights of equal centrifugal arm length.

8. In a reciprocatory tool, a tup mechanism for reciprocating the tup comprising a centrifugal weight pivotally, mounted on the tup, a casing inclosin said tup, an abutand 'aspring between said abutments.

9. A reciprocatory tool as specified in claim 8 having means for adjusting one of the abutments, so as to vary the compression of the spring.

10. In a reciprocatory tool a tup, mechanism for reciprocating the cup comprising a cross pin mounted above said tup, a revoluble Weight eccentrically mounted on said pin, a driving shaft, gearing splined on said shaft for rotating said weight and means for rotating said shaft.

11. A reciprocatory tool comprising a driving shaft, a driven shaft, a coil spring interposed between said shafts, a reciprocatory tup, a. centrifugal weight mounted on said tup and gearing for rotating said weight from said driven shaft.

12. A reciprocatory tool comprising a tup, guides for said tup, a casing adjustably supporting said guides, a collar on said tup between said guides, springs interposed between said guides and collar, means for adjusting said guides in relation to said collar, a centrifugal weight pivotally mounted on said tup and means for rotatin said weight.

RUDOLF ooLDsoHMm'r.

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