US1975978A - Means for transmitting energy in oscillatory form - Google Patents

Description

*Oct .9 1934' G. H.- SCHIEFERSTEIN 1,975,978

MEANS FOR TRANSMITTING ENERGY IN OSCILLTORY FORM Filed March 16, 1932 2 Sheets-Sheet l Oct. 9, 1934. G. H. scHlEERsTEIN y 1,975,978

MEANS FOR TRASMITTING ENERGY IN OSCILLA'LIORY FORM Filed March 1e. 1932 2 sheets-sheet' 2 Fig Patented Get. 9, 1934 UNilzED STATS MEANS FOR TRANSIVH'ETING ENERGY m OSCELLTORBY FGRD Georg Heinrich Schieierstein, Berlin, Germany Claims.

rlhis invention relates to means for transmitting energy in oscillatory orin.

It is known that mechanical phenomena can be dealt with in exactly the same manner as elec- `5 trical, by assuming, inter alia, that a self-inductance L is' replaced by a mass m, and a capacity C by the elasticity (c representing the mechanical field resistance, equal to the sping force per centimetre).

`l'n many instances, however, this comparison also enables one to ascertain the specinc characteristic features of different arrangements that are diiiicult to differentiate. Thus, for example, devices are employed in the 'mechanical arts, in which inert masses are reciprocated between elastic means, but cannot be classedwith loosecoupled, freely oscillating mechanisms, from which-as can be ascertained by cornparisoi they diier just as much as the technical lowfrequency alternating current does from highrequency oscillation. It may even be asserted that the dierence between the two kinds oi movement is more clearly dened in mechanics than in Lhe case of electricity. .In electrotechnics, the Whole-or pratically the whole-oi the amount of energy of the low-frequency alternato0l ing current generated, for example, by a dynamo,

is uniformly reciprocated-irrespective of the circuit arrangement employed-in a positive manner, with the tempo oi the periodicity', whereas the energy generated in any high-frequency generator is iirst passed to an accumulative` unit (oscillatory circuit) in which a multiple of the energy produced per period oscillates, and from which only a fraction may be withdrawn per period. That is to'say, in the case of the damped,

413 vlow-ineauency (or positive) type of movement, the entire amount of energy is generated and consumed at each period, whereas in the coniparatively slightly damped (or high-frequency) type o movement, a collector is charged frein the source oi energy, in the iirst place, in which collector a multiple or" the energy generated and consumed per period oscillations, and to which onlyv just much energy is supplied as is consur ed waste and useful damping per period.

Boil in electrotechnics mechanics, the

collecor is self-contained unit, and the energy nowing to and iro therein is only in loose connection, both with the source oi energy and the point or er" consumption. That is to say, both the source or energy and the point ci (Cl. Gil-62.5)

consumption are loose-coupled with said collector, whereas in the low frequency, (or positive) type of movement the source oi energy is, in all cases, close-coupled (i. e. to the extent of 100% or nearly so) with the other part of the device.

Oscillation phenomena therefore only be termed loose-coupled when, in the entire arrangement, an oscillatory unit is employed as a collector of energy, to which energy, in oscillatory form, is supplied, or withdrawn from, by 6. means of loose coupling.

The present invention, whichis based on the discovery that oscillatory units can also be emplayed, in mechanics, in cases where gaseous or elastic liquid media are used-as open systems, for practical reasons, whereas, on the other hand, couplings can also, in this case, be designed as circuits, in complete analogy with electrotechnics-species the technical means for solving the aforesaid problem.

Further features and advantages of the invention will be apparent from the following description and illustrations as shown in the drawings, in which Fig. 1 is a side elevational view partially in section of an energy transmitting system containing an energy transmitting cylinder, an energy accumulating cylinder, and a working cylinder connected to a single closed circuit;

Fig. 2 is a side elevation in section of an accu- 85 mulating cylinder in which a pair of pistons move in opposite directions to produce an equalizingj action of the masses;

Fig. 3 is a side elevational view, partially in section, of a means for varying the length of the cylinder space;

Fig. ll is a section of a side elevational View, showing a second modification of a means for varying the length of the cylinder;

Fig. 5 is a side elevational schematic view 95. showing the use of an energy transmitting device for driving a frame saw;

Fig. 6 is a side elevational schematic view illustrating how an energy transmitting unit according to the invention may be used for driving a' mowing machine blade;

Fig. 7 is a section of a side elevational view showing the drive oi an impact device;

Fig. 8 is a section of a side elevational view showing the drive of an impact device having double pistons;

Fig. 9 is a diagrammatic side elevational view showing the arrangement for driving a shaft by use of a plurality oi working cylinders with the aid oi starting cylinders;

Fig. 10 is a diagrammatic view showing an arrangement for driving a common drive shaft by use of a mechanical alternating current; and

Figs, l1 to 15 are diagrammatic views of modiiications of the arrangement according to Fig. 10.

The open oscillatory unit in mechanics corresponds, therefore, to the electrotechnical closed circuit (oscillatory circuit). On the other hand, the coupling device, both in the open and closedcircuit form, is adapted for practical application in mechanics.

Fig. 1 represents a typical embodiment of such a complete device which consists:

1. Of a generator of mechanical oscillations, formed substantially by a source of energy, such as an electromotor m and crank mechanism g, It;

2. Of an elastic coupling, consisting of the piston 7c@ and the two media, 7c and k1, enclosed in the (coupling) cylinder ck;

3. Of the oscillatory unit, consisting of a mass a and the elastic media b and b1, also enclosed in a (collecting) cylinder cs; and finally,

4. Of the energy absorbing (working) mechanism. This latter may perform hammering or stamping, sawing, embossing, pounding, cutting,

or any other kind of work that is in reciprocatory form. It consists substantially of the mass a and the two elastic cushions b and b1, which are enclosed in the (Working) cylinder cd.

In order to set in motion the oscillatory unit composed of the mass a and the two gas or air cushions b, b1, the piston Ico-the diameter and stroke of which must be in accordance with the damping conditions-is reciprocated by the crank `mechanism g, h. In this manner the air on either side of the piston ko and also of the mass a, is alternately compressed and expanded (positive and negative pressure) and consequently a reciprocating movement is imparted to the mass a,

`which, as a freely oscillating system, swings with a wider amplitude at each fresh impulse of energy. This oscillatory unit, therefore, serves, in the aggregation, as an alternating-current compressor. A characteristic differentiating feature v-lbetween the coupling and the oscillating device and is transmitted, through the air cushions b',

bi, to the mass a', which, in turn, is enabled to perform useful work of some kind or other, during its reciprocation.

Turning now to the arrangement of the conduit (Le) which establishes communication between theair cushion k in the coupling cylinder and, in the first instance, the air cushion b1 in the collecting cylinder (oscillatory system), and further between the air cushions b and b (L) or bi and k1.

It will be seen that this is not a mechanical oscillatory circuit-though it is undoubtedly a closed, energy-transmitting circuitbut a coupling circuit, that is to say not a circuit in which the entire energy oscillates in a Vclosed form, but a circuit which, during each period, is able to supply to, or withdraw from, the oscillatory system, only a portion of its store of energy, whereas, in itself, the oscillatory system represents a non-closed device composed of mass and elasticity.

As already mentioned, the oscillatory unit itself l'serves the purpose of storing up in the system a greater amount of energy than is supplied to, or withdrawn from, it. This greater amount of energy oscillating in the system can manifest itself in the forrn of an increased pressure in the elastic medium, or as an increase in the velocity of the moved masses, or in both forms. Even a diminution of one of the two values can be obtained, according to the dimensioning of the oscillatory unit, but, of course, at the expense of a corresponding further increase of the second value. Consequently, the total energy of the oscillatory unit is always substantially greater than that supplied by the coupling member.

A certain advantage is obtained by introducing, into the interior of the system, directional means, such as two springs f and f1 (Fig. l) which prevent the mass a from beginning to move, while operating under the action of unilaterally introduced small quantities of air. Of course, the elasticity of these springs is additive to the elasticity of the air cushions, so that the resultant elasticity determines the specific frequency of the whole system. Nevertheless, the degree of elasticity of the directing means need only be so 'arranged that the piston a is retained in the mldway position.

In order that these elastic means f and f1 may not unduly increase the clearances, the cylinder heads can be designed as shown in Fig. l, or as in Fig. 2, in which latter case the masses a and a1 are correspondingly recessed. The directing means may also be mounted outside the cylinder as shown in Fig. 5.

Suction valves o and vi are provided for the replacement of the coupling medium (compression air, gas or liquid) lost through leakages in the stufiing boxes and the like.

Wherever, for reasons connected with the working operations, it is desired for the reciprocating piston a. to encounter a cushion of air, the intake or outlet conduits L or L can be arranged so near the centre as to be closed by the piston, at an earlier or later period, before reaching the end of its stroke. In the coupling cylinder cs, which has to supply the energy, this is usually unnecessary, though on the other hand, it might often be of advantage in the working cylinder ca. which may be regarded as a coupling cylinder for the purpose of the withdrawal of energy. However, in certain circumstances, it may be desirable, even in one and the same arrangement, to allow the one side of the piston to encounter an air cushion, whereas useful work, such as beating action, is to be performed at the other side as will be later referred to in connection with the device in Fig. 7.

For the purpose of modifying the degree of coupling, or of the amount of energy to be accumulated in the oscillatory unit, a vplurality of intake and outlet passages Pi, P0 may be provided at different distances from the centre and adapted to be closed by cocks Vi, VD.

Fig. 2 represents an oscillatory unit in which an equilibrium of forces is obtained by the employment of two masses a and ai, oscillating with a phase displacement of 186. With this object, the coupling conduits L and L1 are branched, as shown, to lead into the spaces of the collecting cylinder. Suction valves v, v0 and v1 are provided for replacement of the yieldable energy transmitting medium lost through leakages in the stuffing boxes and the like. This arrangement-"M prevents the transmission of vibrations to the environment.

In order to modify the natural frequency of the oscillatory unit, or the compression in the working cylinders, the cylinder heads may be made adjustable. Fig. 3 shows this adjustment effected by means of anges and bolts. In Fig. 4, the cylinder head is screwed on to the cylinder, and thus rendered adjustable.

Fig. 5 shows the above described arrangement adapted, for example, for driving a frame R is the frame of a frame saw, which is connected directly with the piston a of the oscillatory unit by means of the piston rod u. cs is the collecting cylinder and ck the coupling cylinder in which the coupling piston ko is actuated from the crank mechanism g, h. 'Ihe directional means for the oscillatory unit consist of gravity in the downward direction and a spring f in the upward direction.

Fig. 6 shows another typical application, for driving the knife of a mowing machine. 'Ihe nger bar F is attached to the frame of the mowing machine, whilst the knife M is connected with the piston rod 1.'. or" the oscillatory unit.

Since, in mowing-machine knives, the stroke is shorter but the periodicity is higher than in the case of a frame saw, the cylinder cs of the oscil- Alatory unit is preferably shorter, but of greater described, in which the energy is drawn from a special Working cylinder cd (Fig. l), connected in the coupling circuit, and not from the actuated mass of the oscillatory system.

In Fig. 7 for example, the working cylinder ca .is designed so that the whole arrangement can serve as a percussion tool. The passage Li, which may be fitted with a supply cock or valve, is displaced so far towards the middle or" the cylinder that the striker a', reciprocated by alterhating pressure, closes the passage before reaching the end of its stroke, and encounters an air cushion, whereas the passage L admits the air to the under side of the striker right at the end of the stroke, or also through the tool holder n which receives the chisel or bit. Percussion tools of this type, however, have a relatively powerful recoil, whether actuated by alternating air pressure or in the uniflow principle, so that the user often suffers injury through the continuous vibration.

A device, constructed on the same principle, but in which the inertia action is completely balanced, is shown in Fig, 8. In this tool, two concentric cylinders ca' and ca, are provided.

- The inner cylinder ca houses a movable striker a', whilst an annular striker ci, of the same piston area, is movably mounted in the outer cylinder cs". The mass or both strikers is identical, and the air supply is arranged in such a manner that, when the one striker is subjected to pressure from the rigl t hand side, the other is subjected to a pressure from the left, so that they move in opposite directions, With a phase displacement of 180. In this case also, the strikers close the inlet passages and encounter an air cushion, before they reach the handle end of the tool, whereas, in the other direction, they strike against the percussion or stamping tool, or on the intermediate member' 1t carrying said tool. This effect can, of course, also be obtained by using strikers of different mass and correspondingly different stroke. For constructional reasons, it may be sumcient for the masses to be not quite completely balanced, for example when it is desired that one of said masses is to give a greater impact than the other, but this does not affect the invention itself. As in the aforesaid instance, the air may be admitted through the said intermediate member, on the one side, and t. rough the tool itself on the other. In this case also, one or more of the air inlet passages may be adapted to be closed-or opened, in starting-by means of valves or cocks.

When the device is employed as a percussion or stamping tool, the working energy is transmitted by the 'eciprocating mass a, of the oscillating colurnn of air, as shown. It is, however, also conceivable that this reciprocating movement can be transmitted to the outside by a piston rod u-Fig. l--of the oscillatory unit in the cylinder cs, or hy a piston rod u of the working cylinder cd. In the former case, the working cylinder of course, be entirely dispensed with, and the conduit L1 may be connected with L directly in rear of the oscillatory unit. The piston rod u in turn, may then be employed to actuate a frame saw, jig screen, mowing machine knife or a ratchet mechanism, etc.

Moreover, it is possible to supply, from a single oscillatory system a, b, b of sufficient dimensions, a plurality or" working cylinders intended to transmit portions of the energy.

Gn the other hand, it is possible to allow the piston a to act on the crank of a drilling tool, or machine, through the agency of the piston rod u and connecting rod h. In this manner, an alternating flow pneumatic motor is obtained, which, of course, may be of singleor multi-cylinder design.

Fig. ilr shows an alternating-flow motor With two double-acting working cylinders ci and ca', acting on a common crank shaft g with cranks set at 180 and adapted to be fitted with a ywheel S.

The two conduits L and L', which, on the provided cocks R and R being opened, are traversed by an alternating current of air (mechanical alternating current), are connected to the working cylinders, as shown. Inasmuch as such a motor behaves like an alternating-current motor-that is, does not start unassisted-it is provided-after the manner of the auxiliary means adapted for alternating current motorswith the two single-acting auxiliary cylinders ch and cs', disposed at right angles to the working cylinders. They may, however, be replaced by one, double-acting auxiliary cylinder, suitably connected with the two conduits. The auxiliary cylinders are preferably of smaller dimensions than the main cylinder When the motor has attained its normal working speed, the auxiliary cylinders are put out of action by closing the cocks, and the motor continues to run in synchrony, though it may fall out of step, like a monophase synchronous motor, in the event of a considerable overload.

In a similar manner and by suitable arrangement, mechanical polyphase current can be produced, and corresponding mechanical polyphase motors actuated. Fig. l0 is a diagrammatic representation of the requisite arrangement for a triple-cylinder generator of mechanical polyphase current, and serving, at the same time as an example of a merely single-acting arrangement of the subject of invention. In thiscase, the coupling cylinders ck, ck and ck" are built into the vcollecting cylinders cs, cs and es, the pistons of which are designed as annular masses, and the three resulting cylinder units are oiIset at about a common crank g. The coupling cylinders communicate with the collecting cylinders through passages L0, L0 and Lo".

. As a matter of principle, the collecting cylinder may, of course, also be separated from the coupling cylinders, as shown in Fig. 1, in which case the connections can be arranged, for eX- ample, in the following manner:-

When coupling cylinders, open at one end, are employed, they may, with advantage, be disposed in star connection (Fig. 11), and the collecting cylinders be arranged parallel to the coupling cylinders.

In Fig. 12, coupling cylinders, open at one end in star connection, are again employed, the collecting cylinders on the other hand, being disposed in the conduits themselves. Consequently, both typesof cylinders are connected in series.

rIn Fig, 13, double-acting coupling cylinders, in triangular connection, are employed, the collecting cylinders being disposed in the connecting conduits, that is, in series connection with the nrst-named cylinders.

Fig. 14 shows the same method of connection of the coupling cylinders, but with the collecting cylinders disposed in the conduits, after the manner of Fig. l2.

Finally, Fig. 15 shows both the coupling and collecting cylinders in triangular connection, parallel to one another.

' The entire omission of control devices is inherent in the principle of the alternating movement. That is to say, whereas mechanisms that are operated by pneumatic pressure on the (di rectcurrent) unilow principle must be provided with control devices, a simple tube, containing a -close-fitting mass in the form of a piston will suice-in the region of mechanics-to actuate a piston by the aid of an alternating flow, being reciprocated by said flow, even without any controlling device or the like.

Consequently, all the mechanisms are quite simple, and also light and inexpensive, since the control parts in the working member are not moved with it, and, of course, must not be taken into consideration with it.

Moreover, in the case of large outputs, such as a large number of tools working simultaneously, the alternating-current system does not require the large accumulatore needed for the uniflow system, and, in addition, the readiness with which the tools become frozen up by a gaseous material expanding in a single direction, is eliminated because, in all cases, an expansion period is followed by a compression period of equal energy.

I claim:

1. In an apparatus for the transmission of energy, the combination of a plurality of units each comprising a cylinder and a piston movably arranged in the cylinder, a closed circuit containing elastic fluid columns, all cylinders being connected to said closed circuit in such a manner `for imparting the reciprocatory motion of another piston to an energy absorbing mechanism, a mechanically oscillatory unit which consists of a mass comprising one of Said pistons and of elastic means comprising elastic fluid, the said rpistons being so shaped and operated that under operating conditions the relation between the volume displaced by the piston forming part of the mechanically oscillatory unit and the volume displaced by the other or by each of the other pistons corresponds to the relation between the amount of energy accumulated in the mechanically oscillatory unit and the amount of energy going through the mechanically oscillatory unit in each period, the mass and elasticity of the iluid columns contained in said circuit being such that the natural frequency of said columns lies beyond the frequency of operation.

2. In an apparatus for the transmission of energy, the combination of a plurality of units each comprising a cylinder and a piston movably arranged in the cylinder, a closed circuit containing elastic fluid columns, all cylinders being connected to said closed circuit in such amanner that upon pulsating motion of the said.v

elastic uid columns the said pistons are put in reciprocating motion and vice versa, means for putting one of the pistons in reciprocatory motion, means for imparting the reciprocatory motion of another piston to an energy absorbing mechanism, means for modifying the amount of the transmitted energy, a mechanically oscillatory unit which consists of a mass comprising one of said pistons and of elastic means comprising the said elastic fluid, pistons being so shaped and operated that under operating conditiors the relation between the volume displaced by the piston forming part of the mechanically oscillatory unit and the volume displaced by the other or by each of the other pistons corresponds to the relation between the amount of energy accumulated in the mechanically oscillatory unit and the amount of energy going through the mechanically oscillatory unit in each period, the mass and elasticity of the fluid columns contained in said circuit being such that the natural frequency of said columns lies beyond the irequency of operation.

3. In an apparatus for the transmission of energy as denned by claim 1 in which three units are provided, the piston oi the iirst unit being connected to a driving mechanism, the piston of the second unit forming part of the mechanically oscillatory urn't, the piston of the third unit being connected to an energy absorbf ing mechanism, all units being connected to they closed circuit in series.

4. In an apparatus for the transmission of energy as defined by claim 1, in which the cylinder of the mechanical oscillatory unit is provided with two pistons operated with a phase displacement of 180, the corresponding spaces of the said cylinder being connected to the closed circuit by branched pipes.

5. In an apparatus for the transmission of enegy as defined by claim l, in which the cylinders of some of the units are subdivided in two concentric chambers for receiving two separate pistons operated with a phase displacement of 180, the corresponding spaces of said chambers being connected to the closed circuit by branched pipes.

6. In an apparatus for the transmission of energy as defined by claim l, in which for the purpose of asymmetrical energy transmission the cylinder of a unit imparting reciprocatory motion to an energy absorbing mechanism is connected to the closed circuit on that side in which the useful workis given up by means or" a channel opening in the neighborhood of the cylinder cover, while the connecting channel on the other side of the cylinder is periodically covered by the piston so as to form an enclosed cushion accumulating energy in one of the limiting positions of the piston.

7. In an apparatus for the transmission of energy as dened by claim 1 in which a plurality of separate closed circuits are provided which are equally displaced With regard to energy transmission and each being connected to a plurality of units, the piston of each one of the units connected to the separate circuits 'being connected to a common power transmitting shaft with a displacement corresponding to the phase olisplacement within the separate circuits.

8. In an apparatus for the transmission of energy as deiined by claim 2 in which the means for modifying the of the transmitted energy consists in that the cylinder of the mechanically oscillatory unit is provided with a plurality of inlet passages located at different points along its axis and controlled by valves by means of which the piston of the mechanically oscillatory unit is periodically isolated in such a manner that it cornes into contact With the closed elastic uid cushions.

9. In an apparatus for the transmission of energy as defined by claim 2 in which the means for modifying the amount of the transmitted energy consists in that the heads of some or all cylinders are arranged so as to be axially displaceable in order to vary the capacity of such cylinders.

i0. In an apparatus for the transmission of energy as defined by claim 2 in which the means for modifying the amount of the transmitted energy consists therein that the closed circuit is provided with regulating Valves for changing the pressure of the elastic fluid contained in the said circuit.

GEORG HEINRICH SCHIEFERSTEIN.

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