BE464847A - - Google Patents

Description

       

   <Desc / Clms Page number 1>
 



    "Improvements to Transfer Control Circuits and Controlled Devices" The invention relates to a transfer control circuit and to the devices thus controlled. It applies in particular to a circuit serving to control and quickly transfer the excitation of an electric load supplied by direct current to another load. for example in certain combinations of slip clutches, brakes, electro-magnetic dynamometers or the like.
The invention proposes in particular to achieve:

     ... a circuit carrying out the transfer quickly. electrical excitation from one exciter device to another, for example in clutches, brakes and dynamometers of the electromagnetic type, the transfer responding to changes in load or speed or between ruDtion of another circuit - like the ignition circuit of an internal combustion engine

 <Desc / Clms Page number 2>

 - apparatus of the class indicated performing precise speed control functions on a driven component within wide speed reduction limits;

   - a circuit of the class indicated which applies in particular to the transfer of excitation loads between the excitation devices of the various components such as dynamometers, slip clutches and electromagnetic type brakes so as to obtain said precise adjustment of the speed of members driven by these deniers, carried out under conditions of wide variations in the load; - a circuit of the indicated class carrying out a
 EMI2.1
 safe transfer operation in reduced or significant excitatim conditions, Depending on the iovention, a driving member antions a member driven by an electric coupling or clutch and an electric brake with means responsive to the speed of the driven member to actuate the coupling or clutch and brake.



   In the attached drawing, which shows several possible embodiments of the invention:
Fig. 1 is a schematic representation showing an application of the invention to a grinding machine.
 EMI2.2
 



  Fig. 3 is a main connection diagram.



   Fig. 3 is a secondary connection diagram showing parts of FIG. 2 and reworked to explain some bridge circuit relationships.



   Fig. 4 is a schematic representation showing an application of the invention to an engine test dynamometer.



   Fig. 5 is a reproduction of part of the main connection diagram of FIG. 1 showing variants for accelerated transfer of the load, in particular in applications such as represented in FIG. 4.



   Referring now more particularly to FIG. 1 M is an AC motor whose shaft Ds drives the armature A of an electromagnetic slip clutch C, using eddy currents. At F is the driven inductor member of clutch C with winder
 EMI2.3
 L excitation ment. This winding L is supplied by a circuit which will be described later, and thanks to the interposition of friction rings SR i. The excitation shaft is carried by the shaft SH which it drives. The SE shaft also carries a RO-2 frame, wedged on the shaft, inside an excitation member ST of an electromagnetic brake BR with eddy currents.

   The brake BR has an excitation winding B, On the shaft SE is wedged the armature U of a small, 1

 <Desc / Clms Page number 3>

 GN permanent magnet adjustment generator responding to speeds.



   The SH shaft is coupled in a drive connection with a grinding wheel, which is one example, but not the only one, of the type of mechanical load re-
 EMI3.1
 glée by the apparatus according to the invention. It is representative of a mechanical load member which can tend to move forward or completely separate its load from the driving member and the speed of which will have to be regulated. This is an improvement in modern grinding machines.

   In these machines, the part to be worked on is drawn into the
 EMI3.2
 same tangential direction, at the point of contact with the grinding wheel, as the periphery of the grinding wheel and
 EMI3.3
 by advancing it in its rotation, which gives a better. finite, more precise and of a higher degree of polish, However, a difficulty arises in certain parts of the operation, as, for example, in the case where the grinding is very slight, Under these conditions the the workpiece tends to drive the grinding wheel faster, with which it is in direct contact.

   As a result, the grinding wheel tends to spin faster than it should to give the results an eye. 0 is why it is necessary to have
 EMI3.4
 a source of energy to drive the grinding wheel, but also the same source must be able to retard the grinding wheel and
 EMI3.5
 to maintain it at a given speed of rotation against this excess drive. The invention will produce this result, alongside others.



   Fig. 1 is a diagram showing the application of the invention to a load of this kind. The alternating current induction motor M. drives the shaft of. ordered
 EMI3.6
 DS. This drives the shaft SH by means of the aocouple or electric sliding clutch of the eddy type mentioned above. The armature A is an eddy current member surrounding the field poJa1 .. re radial created P, Fr the excitation coil L. The toroidal flux field generated by the annular coil L and the polar elements F crosses the armature A in which are generated Fouoault currents reacting against the flux
 EMI3.7
 eL "d: eg4e 'the electro-magnetic coupling depends on the field of the coil L 1 and consequently. on its excitation.

   The RO-2 rotor of the BR brake is an eddy current member in the polar field emanating from the brake coil B. The toroidal flux field generated by the annular coil B
 EMI3.8
 and 1 fixed pole member 8. 'crosses the RC rotor 2 in which eddy currents arise which react against the flux.

   Thus the excitation of the coil B can cause a retarding effect on the shaft SE * The circuits that will be described are contained in a box 0 on which there is an adjustment knob H of a potentio "
 EMI3.9
 meter The transfer circuits respond to the current coming from the generator to transfer the excitation between the coils and B in order to tightly regulate the speed of the shaft even under the most unfavorable mechanical conditions. or others of the load% 4 In what follows, the potentials and the current passages will be designated according to the movement of the

 <Desc / Clms Page number 4>

   negative electrons in the respective circuits.

   For example, an element of a tube from which negative electrons come out will be said to be negative; an element in which these electrons enter will be said to be positive. Likewise if negative electrons are abundant on a first element and not on a second element of the same circuit, then the second element will be considered as being positive with respect to the first,
Referring more particularly to FIG.
 EMI4.1
 Sections I and 1- of the circuit are the main recovery portions of the circuit.

   Circuit II constitutes a reference voltage circuit; III is an adjustment circuit, IV an amplification circuit and V, a bridge circuit,
In circuit I which is a main section
 EMI4.2
 to straighten, is placed a rectifier tube 3 for controlling the clutch with grid adjustment, and a discharge tube 4 at the same time as the load winding L of the excitation of the clutch. In the current example, the load L
 EMI4.3
 is the direct current excitation coil of the eddy current and slip C engagement (fig. 1).



  At I-A is shown a rectifier section arranged in parallel and in this there is a rectifier tube 1 adjusted by grid and used to adjust a
 EMI4.4
 brakes an echelon tube 2, and the load element B.



     The load element B is the energizing coil of the electromagnetic brake BR of FIG. 1 for example, The goal pursued, as indicated above, is to
 EMI4.5
 transfer the excitation or the electric charge from coil L to coil B, and vice versa, in response to certain variations, such as those of the mechanical load and or of the speed, the aim being to keep the speed substantially constant of the SH tree despite said variations.



  To ensure the best adjustment, from time to time the excitation load must be transferred rapidly from one to the other of the excitation elements L and B of the clutch and brake. The excitation of L tightens the mating the en
 EMI4.6
 clutch for the acceleration.ilors a drop in speed (the brake B no longer being supplied). The excitation of B increases the braking action with a view to slowing down following a start of speed increase (clutch C no longer being supplied).



   Tubes 1 and 3 are both grid-regulated gas-filled tubes, typically employed for motive power applications and characterized by the
 EMI4.7
 that although the grid of the tube can give rise to the anode current, the grid cannot stop it. however, when the AC anode voltage is passed through, the current automatically disappears. The effect of the action of the grid is to ignite the tube corresponding to one point or another of a branch of the alternating wave of the anode voltage. Continuous currents of different mean values circulate and are determined by the action of the grid.

 <Desc / Clms Page number 5>

 



   Tubes 2 and 4 are similar, but, as can be seen in the drawings, they are not set by grid, They are rectifiers having substantially the same
 EMI5.1
 rapacity of current, that tubes 1 and 3 ..



   In AT is shown an anode transformer having a PA primary and ST-1 and ST-2 secondary sections. The primary PA is connected to one phase of a three-phase AC supply circuit. Thus the ST-1 section of the secondary applies an alternating voltage to the anode of tube 3, as long as the grid G-1 and the anode of tube 3 are sufficient.
 EMI5.2
 positive, its cathode K., w7 passes current - to the anode and through the coil L of the clutch, through points T-4 "T-2" the conductor W 7 and the midpoint T -15 of a secondary section KW de cathode of a power supply gen- eral transformer FT The current returns to the cathode K-7 of the tube 3 by the wires W-1 or W-3.

   The primary PF of the transformer FT is connected to another phase of the AC power supply. Thus the tube 3 becomes a half-wave rectifier and the current, which passes through it, exists only in the period of the alternating cycle where the anode of the tube 3 with grid adjustment is positive.



   As the coil L has a relatively high inductance and since it is in a current group
 EMI5.3
 continuously, energy is stored in it during a period of increasing current in the cycle. When the raotified current stops being sent by the tube 3, this energy stored in the 'coil L as well as the voltage,' par.suî.

   The beginning of the decrease in the flux surrounding the gas coil tends to prolong the flow of current in the same direction in the circuit mentioned last, However, as tube 3 becomes non-conductive when the anode becomes negative, this prolonged current coming from of coil L bypasses tube 3 and finds a passage through tube 4 which was inactive while tube 3 was active, Tube 4 is inactive while tube 3 is active $, because the anode of tube 4 is connected to the negative terminal of AT when the anode of tube 3 is positive. Thus under the tendency of the coil to discharge, the tube 4 prolongs the passage of the current in the coil It follows that an average current can be maintained in the coil L without interruption,

   unless desired, although tube 3 is a rectifier of
 EMI5.4
 half wave. The pass through tube 4 is essentially determined by the value of the current established by the tube
The purpose of this arrangement of the tube at the bypass is threefold: i) It achieves an economy in each of the rectifier systems by the use of a single regulated tube per grid, which is more expensive than the rectifier without grid. - 2) It preserves the rectifier tube 3 from a high reverse voltage that the direct current would otherwise apply to its cathode / and to its anode during the inversion
 EMI5.5
 of the alternating cycle killed potentials applied to the tube 3.

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   3) It simplifies the ci: cooked,
In short, the use of the tube 4 makes it a complete rectifier serving to discharge the coil L by a weak shunt resistance, thus saving the tubes and the elements of the circuit; preserving tube 3 from the dangerous reverse potentials which would otherwise occur.



  In practice, the adjustment of a rectifier system as described is substantially as sensitive and as flexible as if the tubes 3 and 4 were both grid adjustment.



   Cubes 1 and 2 in section I-A are similar to tubes 3 and 4 respectively and they are similarly arranged in a parallel circuit as it
 EMI6.1
 is represented. In this case, the two items section ST-2 of the anode transformer AT is connected between the anode of tube 1 and the brake adjustment coil B and from there to point T-4
 EMI6.2
 through the resists, -. this R-B. The operation of the tube 1 to send direct current to the coil B, in connection with the rectifier tube 2 is evident from the drawing and the discussion above about tubes 3 and 4 :. Note that any current flowing through coil B also passes through resistor RB
A reference voltage is established by means of circuit II which will be described.

   The purpose of the latter is to establish a level of potential to adjust the grids of
 EMI6.3
 tubes 3 and 1 of the main circuits I and I-A. Note ivi that the reference voltage can be applied directly to the gates G-1 and G-2 or indirectly as in the current example, through an amplifier tube such as 5. The reference voltage of circuit II to his
 EMI6.4
 origin in an RA section of the secondary of the tr, nsforn18te.ur FT. The negative rectified current comes from the cathode K-3 of the tube 6, being caused by the action of the section RA of the transformer. The cathode is heated by the connections
 EMI6.5
 't-5FT from another section of the RA secondary, as noted.

   This section sends current during a
 EMI6.6
 part of the cycle through point T-14, a branch of the flat transformer at the liUle,? - 3 at the point of junction T-ll. At this point, the circuit divides. A branch leads through resistor R-14 to point T-12 (bypassing a resistor R-13) and then to cathode K-2 of an amplifier tube 5 passing
 EMI6.7
 by driver Z11-6. The other branch leads to the potentiometer PT, which is crossed, and from there, by line V, 1-119 point T-10 ', resistance R-12, point T-13, choke CH, line \? - 4 :, and back to cathode K-3 thus completing the circuit.
 EMI6.8
 The combination of resistors R-13 and lfl-14 produces the effect of a voltage divider.

   Point T-12 has a negative relative potential which (in accordance with the
 EMI6.9
 their resistances indicated in the cease), is lower than the full negative potential of the point 'in-16, in the potentiometer PT. Thus the PA arm of the potentiometer PT can bring its connection wire Vi-5 (connected to the cathode K-1 of the tube 5) to a more negative potential than the wire il-6.



  Tube 8 is a cold cathode tube, It con-

 <Desc / Clms Page number 7>

 
 EMI7.1
 time an automatic leak resistance in the ..u.11i 119 and due to its own characteristics causes under certain conditions a Gour 1i .... o1r.a t relative on core tains potentie3a on ie8qtl1.a1l.a 11. can to be bretaa'hd. , .A.1D.a1 "in the case where the voltage on the o1rC \ l1t 'd. Tube 8' nd increase 1ndttlDlmt above the nominal value of the circuit the tube becomes more conductive and releases the circuit asti is connected to it of a current sufficient to. learn more than an incipient evaluation of voltage * In the case,, c. and., a6La maintains the oirouit 114 which is there or is apprehended with the v81etrnmie of network.

   The self. eH and the condenser Q2 carry out the filtering hab1 tu.ellem81 + 1i d6elxë d airmit II of reference voltage * The effect of the reaictanee R-le will be expoaé further * Dono au moyoi 4 bras'] Pe au. potent1om't1'e. hand-set potentials * weigh to be applied at point T * 9 of the receiving circuit; 1on 111 that your Ta deor1r, e.



  Once established at: ciaïn4, ¯a given potential is substantially constant. If the arm, 9à is turned r '.ë point M6f 1> 9 deTienara then ple1nEllt.t nigfttlr', 10 and tau the circuits which are connected to it will be abundantly fed é1réqtrpn .. negative. If the arm And is turned on the terminal .hli19 <s the circuits which have therein, comect. will be relatively posed rod # being deprived of negative electrons.



  Coming back a. the praniere position da. arm .1 i
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 namely% * le if the arm is placed on this point the cathode
 EMI7.3
 K.1 of tube 5 will become eseeU.8Il¯t fully U66qtîve (passing through 1 oompre # nt 89j Bais the free grinding of the negative current is prevented by the resistor Ré9,.



  The grid G * 5 of tube 5 will be re18.1; 1 "'- I1't positive and ¯ negative current will flow, from the cathode ïM. & The ¯ooe- responding anode of tube 5 and to the circuit W <" 18 connected to it.
 EMI7.4
 We will show the resulting effect. Tube 5 is heated
 EMI7.5
 by the ZZ connection to a cathode through a section of the secondary of the transformer PS The generator #SF is used to supply the regulator circuit III in relation to the speed of the generator, that is to say with the speed of the generator. driven shaft
 EMI7.6
 SE [(Fig. 1). There is not necessarily proportionality
 EMI7.7
 direct ,, maia -0 'is preferable.

   Circuit III is supplied by the GON generator through a transt # ¯tor the En
 EMI7.8
 principle * the circuit begins with a flow of electrons
 EMI7.9
 negatives coming from the K "cathode 4 of tube 7 and passed through the second 6 of the TR transformer. The cathode is heated through the X * X elements by a section of the PIC transformer of the TR transformer, the current passes through W-09 containing the resistor a10, the grid a.4: of tube 5. The return is made through the gas cathode of the.,; tube 5p the line W "Jll6 the point" 12, the resistor .R14 , the point llt the 1PJÎ.wpoten t10111 meter PT, with return through the arm Bit the point and through 151 to the cathode K <t4 of tube 7.

   A part in parallel of this circuit pput be drawn as follows: Cathode Ké4 towards an anode of the tube? point 24e cla tranercrmateur. 9Rt 19 * 810 resistance 7.2 .; point 9 and return to the tube cathode w4? by W "814 Des couden". Suitable sators 0-a and C <5 shunt resistors Rll and R..10 respect1vElUl t0. 8hutte- ive <réRiatanoos

 <Desc / Clms Page number 8>

 
 EMI8.1
 By moving the bra; Yd3a potentiometer from T-16 to T-17 the clutch bohine, as seen, is gradually energized, tightening the coupling from
 EMI8.2
 clutch n3gné-tique and causing an increase in speed of the driven shaft SE, It follows that the speed of the generator GN increases.

   At a c rt-in point, we will stop the PA arm and under these conditions we will obtain a potential which is in a defined relation with the potential.
 EMI8.3
 tiel obtained at point T-16. As the potentials generated by the GN generator are then below that established by the PA arm, the position of PA determines the speed at which the clutch will accelerate its driven member and the generator, a balance s 'finally establishing as seen. Likewise if at a certain position given to the arm PA the mechanical load on the machine driven by the clutch C decreases, the shaft SH accelerates. In other words, the speed set by energizing the coil this load L (for a larger load) will increase for a smaller load.

   The GN generator will give
 EMI8.4
 again a greater voltage as a result of the final increase in speed.



   The cathode K-2 of tube 5 operates at a fixed negative potential because it is permanently connected.
 EMI8.5
 nence to T-12 through wire W-6. Its negative potential will be about JL, 12 volts less negative than point T-16; well the point T-16 is 1.12 volts more negative than T-12.



  Thus, even taking into account the resistances R-10 and R-11,
 EMI8.6
 a relative negative potential can be applied to the G-4 notch by turning the PA arm to the T-16 point. This makes the G-4 grid more negative by 1.12 volts than the K-2 cathode and tube 6 is completely annihilated. As long as PA is moving clockwise to T-17, gate G-4 first reaches zero potential with respect to cathode k-2 and then becomes relatively positive. It follows that the G-4 grid will ignite the K-2 cathode which sends negative electrons to the G-2 grid of tube 1 which excites the brake. This destroys tube 1, as well as the excitation of coil B of the brake.



     ] when the cathode k-2 sends negative electrons to the point T-5, a good part of these last passes
 EMI8.7
 feels through resistor R-6 at point T-10e to then return to cathode K-3 of tube 6, passing through it-11, R-1 &, T-13, choke CE and i1T-4, En at the same time, the system T-5, T-1, R-3, T-2, W7, T-15, Wl, K-7 charges negative electrons up to the potential Ith @ ot1t} ue (static) of -140 volts referring to T-10j a loss of 10 volts occurring through the tube R and R-6. There is also a 150 volt drop on R-8 and R-7. T-6 being at. half a potential between that of the ends of R-7 and R-8, there is a potential of - 75 volts with respect to T-10.

   So, T-6 being connected to the grill-
 EMI8.8
 the G-1 of tube 3 through resistor R-1, is at -t- 75 volts compared to the -140 volts of cathode K-7. This makes the grid G-1 of tube 1 positive with respect to the cathode K-7 of this tube, consequently tube 3 ignites and energizes the coil L.



   This situation continues until the
 EMI8.9
 speed of the SH shaft and the UN regulator is one point

 <Desc / Clms Page number 9>

 where the voltage of the GN regulator exceeds the established voltage
 EMI9.1
 pa the potentiometer pA, i.e. if the voltage of the GN generator rises sufficiently above the restoration of the speed, negative electrons in sufficient quantity will come out of the cathode K-4 of the tube 7 and, in passing through wire W-8, the grid G-4 of tube 5 will become more negative than the potential of T-9, because the current passing through resistor R-11 will be reversed.

   In addition, the negative potential through the W-8 wire will be predominant, causing
 EMI9.2
 as to the reduction or complete ltunliulation of the anode aouirants indicated above. Negative electrons coming
 EMI9.3
 from point T-12 will go through wires W-6 and W-9 and pxé90 will again go to grid G-1 of tube 3 and annihilate this tube.
 EMI9.4
 



  At this time the bridge system V coupled to the circuit IV functions in such a way as to make the grid G-2 of the rectifier tube of the brake relatively positive, by causing the ignition of this tube and by operating to energize the coil B brake, The details of this operation will be described here. As we see, when the GN generator gains in-voltage, it annihilates the tube 3 by the action of the grill G-1 As the operating characteristics of the system.
 EMI9.5
 main rectifier I-A are similar to those of rectifier system I, instead of applying full exci-
 EMI9.6
 tation of the brake coil B, the system tends to adjust the braking effect exactly as described for the load coil L.

   This braking effect is maintained until the machine is brought back to its original speed set by the PA potentiometer, and if the speed then continues to decrease, the main rectifier circuit I will assume the function of regulation by the circuit. I, the IA circuit switched off again released.



   Circuit V may be referred to as a bridge transfer circuit which operates in association with rectifier circuits I and I-A Its purpose is to instantaneously switch or displace the operating potentials.
 EMI9.7
 ment of 1G grid G-1 from tube 3 to grid G-2 from tube 1, performing the transfer operations between the two. To make the description and operation clearer, FIG. 3 has been drawn to illustrate the relationship of the bridge. The reference signs correspond. It has not been shown in FIG. 3 that the elements which actually regulate the system and comprising the two elements of the tube 5 which, for the sake of clarity, are shown divided into two
 EMI9.8
 groups 5a and 5b.

   The electrical pibnt and the related circuits have been stripped of all secondary elements to allow a relatively simple analysis of the essential principles.



   It can be seen from FIG. 3 that a bridge is defined by three resistors R-6, R-7 and R-8 and the element 5b of the
 EMI9.9
 tube 5. The impedance of this element 5b provides resistance.



   A reference voltage (150 volts for example) coming from W-6 and W-11 of circuit II is applied to the bridge
 EMI9.10
 in T-7 and T-) 0. If all branches of the bridge had the same resistance, the voltage drop from T-7 to T-6 would be

 <Desc / Clms Page number 10>

 equal to half of the -total, and an equal fall would occur between T-7 and T-5.

   However, as long as the tube elements 5b are not in action, they are practically imperative.
 EMI10.1
 infinite dance so that, with the completely negative G-4 grid, the voltage between T-5 and T-7 is 150 volts,
 EMI10.2
 s, ns au-, a current flow through R-6 Assuming that one scits ns rie #. starting conditions with the PA arm of the Pt tiometer buddy on point
 EMI10.3
 T-16, negative voltage is supplied from T-16 through 'J-3, resistor R-11 and to grid G-4 of elements 5b of the tube. The grid G-4 becomes fully negative and the elcfients 5b of the tube become inoperative.

   As a result, the potential of 150 volts is established between the cathode k-2 and
 EMI10.4
 the anode of said elements 5b of the t: be d-ns the bridge. At the same time, however, the .5z elements of the tube allow current to flow, because the G-3 grid is operating almost at full capacity at the grid-to-cathode potential between 0 and - volts, due to the characteristics. tube characteristics. As a result, negative electrons leave the K-1 cathode and pass through the elements.
 EMI10.5
 5a and arrive on the cathode K-6 of the rear brake tube 1, whose grid G-2 is fully positive (@ 150 volts). So tube 1 energizes brake coil B.



   If you turn the PA arm clockwise
 EMI10.6
 clock, the potential of wire Va-5, resistor 1-11 and gate G-4 is positively increased, so that gate G-4 becomes relatively positive and tube elements 5b come into action. or light up. At the same time, the
 EMI10.7
 dathode K-1 of the elements 5a of the tube becomes more positive, in ren,., nt ln grid G-3 negative and by stopping the passage of the current by the elements 5a of the tube. The elements 5b of the tube, when they come into action, having an impedance less than the resistance R-8 result in a potential drop of the point T-5 less than that of the tube 1 brake rectifier under the conditions. operations considered so (and this happens gradually) that the tube 1 reduces its braking excitation.
 EMI10.8
 



  At the same time the sQustr? Ctive action of the elements 5b of the tube will lower the potential of T-5 to T-7, for example from 150 to 10 volts. Under equilibrium conditions, the potential between T-6 and T-5 is 75 volts, because the potential of T-5 is the same as that of T-10. So like
 EMI10.9
 between wires W-10, and W-9 (7-5 to T-5 '}' the conditions change from w-10 for example at t 150 volts, and from w-9 at t 75 volts, to achieve a condition om the
 EMI10.10
 y'd-10 wire is at + 10 volts and wire W-9 at t 75 volts, or, relatively, wire w-9 is at a potential of 65 volts plus
 EMI10.11
 higher than the vr-10 thread. Comr #, resistors, -3 and R-4 divide this voltage, the, point T-2 becomes negative by 32.5 volts compared to T-3Set T-6.

   Consequently the grid G-1 in the clutch tube 5 becomes positive with respect to the K-7 method and consequently the tube 5 ignites thus energizing the clutch coil L. This tightens the clutch coil. ac-
 EMI10.12
 magnetic coupleme1j.t with 1 <rb motor SH and accelerates 31a GN generator. As the voltage oe 1 empress GN increases, negative electrons leave from K-4 and pass

 <Desc / Clms Page number 11>

 at the anode of the tube 7, by the secondary winding of the transformer TH, the resistpce R-10 and at the grid G-4 of the elements 5b of the tube. This tends to make the grid G-4 relatively negative and causes a decrease in the activity of the elements 5b of the tube.

   This process continues, establishing close adjustment of the clutch drive speed.



   As noted above, yes. the load on the clutch is overloaded or weakened, the shaft SH accelerates, causing the GN generator to charge the grid G-4 even more negatively, completely destroying the elements 5b of the tube. This returns the bridge circuit to its original condition where the grid G-2 of the brake rectifier tube 1 is positive and the brake is thus energized, Under these conditions also, the clutch rectifier tube 3 is annihilated because:

     that points T-6 and T-1 become negative with respect to T-2, G-1 being negative with respect to its cathode k-7, following which tube 3 is completely annihilated. 2 'As soon as the brake BR is energized and in action, the regulator GN regulates the braking effect because when the speed decreases, the aotion takes place through the tube T1.



   It can also be seen that the generator directs and regulates both the coupling of the clutch and the action of the brake, that is to say that it controls both the accelerating and retarding action. This tends to keep tightly constant. the speed of the shaft SH, either despite relatively small variations in the load, or despite radical changes in the load, including the complete removal of the load. The system will apply the brake not only if the speed of the SH shaft is required to increase as a result of the load reduction, but also if the SH shaft tends to run away and actuate the eddy current coupling and the brake.

   In this last condition, the brake will apply a sufficient retarding force to regularize ,! runaway or excessive entrainment of the load, so that it will maintain substantially constant the primitive speed as set by the Pt potentiometer. The advantages of the invention are not found in prior systems where a regulator only tightens or loosens a magnetic slip coupling between the driving and driven components. This is partly due to the fact that the old systems do not have the means of adjustment to delay the driven organ until it responds to the action of the regulator. The cooling was effected simply by the mechanical load supported and if this load suddenly decreased, the friction could not be sufficient to slow down the apparatus quickly enough.

   Thanks to the present invention; the adjusting action of the brake is applied to slow down, in addition to the delay normally caused by the load. Thus, under any conditions, the speed adjustment is faster and narrower than previously. Due to the invention, the load on the drive shaft of the clutch can be kept tightly at a clutch speed whether the driven machine loads the system, or whether it tends to drive it.

   In practice, the transition between the driving action and that of slowing the load is noticeably imperceptible.

 <Desc / Clms Page number 12>

 ble, except by means of an ammeter in the branch of the AC induction motor, and this ammeter will indicate whether at any given time the motor is drawing power and whether at any other time it is does not absorb any power except the magnetizing current.



     For ? coming to more detailed operation starting from rest, a bypass to completely annihilate tube 3 must exist and is carried out retort follows: T-10 is
 EMI12.1
 fully positive pCiT 'compared to T-7 (130 volts). T-6 is 75 volts po # positive compared to 1-7. Circuit R-5, R #, R-8 (one pass for branch circuit), if calculated for 150 volts, indicates that point T- is at; 117
 EMI12.2
 volts, and T-3, at t 9 'volts. So the G-1 grid is 23 volts negc.ti with respect to the K-7 cathode which is connected
 EMI12.3
 at T-2. All this takes place under static conditions.

   Knob section 5b of the tube works, this condition (considered atatically) is reversed, so that T-3 and G-1 become 32.5 volts positive with respect to T- and K-7, as explained more high.



   The actual conditions when the GN regulator
 EMI12.4
 works are such that the section ib of the tube undergoes continual modifications, the grid potential in CI-1 compared to K-7 of the tube 1 can function :, with a difference of only 3 volts rather than for large values imdigated
We will now consider again the fact that the
 EMI12.5
 base derivation: when at rest is' 1'-3 to 1'-, G-1 to K-7,, 13 negative volts and such a base derivation, under running conditions, is T-3 T-2, positive volts, nominally a difference of 55.5 volts.

   Conne, well
 EMI12.6
 as explained above, the real operating conc.iti <ns @baise the latter, we will admit that this difference is such that it returns the voltage distributed to 9.5 flights during 1 run and the adjustment . It's here
 EMI12.7
 the distribution between the absolute values é..5.:; 1.:, C .: 1,1- ti; .ls: 0, tc.Jt, q'.les. l..a v.; ia;: io u? bise os; ar = t and. ', UtJ:' 2 of zero is not even 23.5 volts negative to 32.5 volts positive. This requires, that turning the potentiometer
PA in the direction of a lower speed, there will not be an instantaneous transfer measured in degrees of the displacement of the potentiometer arm.

   For example, since all the rheostats or potentiometers are inactive, a very small movement or imperfection of the contact will result in. difficulties for instantaneous brake application. Nevertheless, by means
 EMI12.8
 of the aforementioned irregular bypass, it becomes necessary to move the potentiometer at least enough to correspond to 5 or 10 revolutions per minute of variation of 12 speed of the regu
 EMI12.9
 regulator (and hence its voltage) so that, in ordinary operation, an intentional variation on the part of the operator alone will activate the braking effect.



   Section 5a is also used as an action stabilizer at very low drive speeds. When the speed '-; the motor shaft drops to low values, for example 10% of the maximum, the load may in some cases be so low as to cause the motor to fail.

 <Desc / Clms Page number 13>

 bility of regulation by the regulator circuit.

   In this case, it is desirable for stabilization to apply the brake in order to add a small braking load to the mechanical load. When the PA arm is turned to a small amount, as in position 25 in FIG. 3, the cathode K-1 of section 5a reaches a potential for which section 5a of the tube can work (a small negative difference between K-1 and G-3 will be needed), so that the following action occurs : electrons leave from K-1 and, through the anode of section 5a, wire W-12, go to cathode K-6 of tube 1.



  Thus, K-6 becomes more negative than before compared to G-2 and T-5. This amounts to making G-2 positive with respect to K-6, so that tube 1 ignites, applying a load.



   When the arm. Is moved .. further towards T-16, this effect increases. In this way it is possible to achieve a tightly regulated speed reduction, from 60 to 1, for example, on the drive shaft of the eddy current clutch, producing stable rotation at these low speeds. and this action can furthermore be adjusted by hand. , by moving the PA arm.



   Another particular feature consists in that any movement of the PA arm towards a lower speed position is accompanied by a thinning effect by automatically causing a rapid slowdown. This is a valuable result for many manufacturing machines other than grinding machines. When the inertia of the machines is important, this slowing down effect can lead to substantial savings in time and a reduction in cost prices.

   For example, in textile machines, the time for slowing down has been reduced for successive periods of rapid slowing down from 12% to 1.6% of the total time of operation. '
The trade names of the tubes described above are as follows:
 EMI13.1
 
<tb> Tubes <SEP> Designations
<tb>
<tb>
<tb>
<tb> let <SEP> 3 <SEP> EL <SEP> CL <SEP> B
<tb>
<tb>
<tb> 2and <SEP> 4 <SEP> EL <SEP> a'c
<tb>
<tb> 5 <SEP> 7N <SEP> 7G
<tb>
<tb>
<tb> 6 <SEP> 6X <SEP> 5GT
<tb>
<tb> 7 <SEP> 6X <SEP> 5GT
<tb>
<tb>
<tb> 8 <SEP> VR <SEP> -105
<tb>
 
Another interesting application of the circuits described here is shown in fig 4.

   This is shown in the internal combustion engine tests using a combination of absorption dynamotors and motors. The absorption and motor elements of the machine can form one or more groups, but the first is shown in fig. 4. In fig. 4 AD is a polar field stato which can rotate on bearings 161 in a frame 103. The resistive moments of this stator are applied to a recording scale 105 by an arm 107. The excitation windings are shown in Bl.

   The shaft driven in

 <Desc / Clms Page number 14>

 this case is here again designated by SH It turns the sta-
 EMI14.1
 tor AD and entered by the motor under test E. On the same shaft SH, inside the stator AD, an eddy current armature EA is coupled. When the B-1 inducers are
 EMI14.2
 energized, a polar chemp of AD surrounds B-1 in .nd: they ('1nt magnetically reactive eddy currents in EA and!' echâüPtn.3. Thus, energy can be taken on E and measured at 105 The heat can be removed by any conventional method (not shown).



   Inside the EA arpature is an FM polar field member on a Da control shaft which carries the RT rotor of a MAC induction motor. FM field windings are shown in FD. When FD is excited,
 EMI14.3
 a polar field resulting from FM embraces the arm: .. tèire EA, giving rise to reactive eddy currents, thus
 EMI14.4
 can be driven by its electric sliding coupling with FM. The FC inductor of the HAC motor is fixed on the
 EMI14.5
 stator AD. We propose to do this between injecting the inductor tll at a constant speed by the armature RT, but to let enter
 EMI14.6
 run the EA armatue at any speed necessary on the SH shaft because it is driven by the E motor.

   Thus, when the winding B-1 is supplied (FM not excited), AD and EA constitute an absorption dynamometer having the effect of a braking action on EA.



   When FD is energized (B-1 not excited) "there is a slip coupling between RT and EA. Cuckle the MAC motor has its stator supported inside the stator AD, it
 EMI14.7
 can be pa training. t dl], 1ote il 'and the reaction torque due to the drive measured at 105. These elements then constitute an engine dynamometer.



   With devices of this type, it is possible to charge the motor E by means of the elements AD, EA of the absorption dynamometer when B-1 is suitably supplied and the motor RT not excited. When activated, the absorption system AD, EA can be omitted and the driving elements EA, FM can be used to drive the motor E by RT through the shafts SH and DS, the ele- ments dynamometers' not being supplied under these conditions.



   Very often, engine testers need to know the exact friction of an engine that has been running for some time at a determined load and speed.
 EMI14.8
 mined and given temperature and grilling conditions. For example, if an engine capable of operating at a minimum speed of 2,800 rpm at 2,000 horsepower has been running at full speed in a period of one hour, it is very important to know as certain and precisely as possible. how large are the friction losses under these operating conditions.

   If the engine can be detached from its running on the dynamometer AD and instantly driven by the electric motor, the calculations deduced from the reaction torque on AD will provide the frictional power at the instant and under the conditions existing at the time. where the engine was under full load.
 EMI14.9
 clearly that if the B-ballast coil is the iifigL4, we can see

 <Desc / Clms Page number 15>

 The engine is still running at full load and at full speed, it will be very valuable to be able to operate the.

   RT motor without supplying the FD inductors and to prepare it thus for a quick test of the friction power by passing codes
 EMI15.1
 of absorption to those of running in motor, Thus the armature EA oontin # ra toirner without stopping during the operation of the combination EA, AD of the dynamometer
 EMI15.2
 absorption but there will be no coupling between to and the FM inductor system. By using an electronic comoame of the kind described, a simple element will be available in the hands of the operator to cut off the ignition and
 EMI15.3
 the gasoline and at the same time the excitation of the coil B "'l.



  Then the DIiG motor drives the machine E to. a speed practically the same as that at which it was running under load This involves the same problem as in the example described above, in particular because the system is suddenly held without load, except for the power taken by the
 EMI15.4
 frotiaments, conditions under which it is desired to transfer controlled and regulated in a substantially instantaneous manner, between absorption and driving conditions.

   Thus the en-
 EMI15.5
 bearings B-1 and FD in 3a: fig. 4 are the equivalents of coils B and L respectively of 1'ig.l, with regard to the circuits of fig. 2 and 3
 EMI15.6
 It must be understood from the point of view m, 6oa nique, some or all of the elements represented in fig. 4 of the absorption dynamometer can be separated from the parts of the engine dynamometer.



   May figure 5 is a diagram of the connections of the main rectifier circuits I and I-A for
 EMI15.7
 accelerate the transfer of the excitation between the coils L and B. The same numbers designate the same parts. This variant is especially useful for the use of the type of device.
 EMI15.8
 reils represented and described in fig. 4 where one seeks the rapid transfer of the excitation, It consists of a re-
 EMI15.9
 sistor R connected to the two electric charges L and B which must be exchanged between them by the c3.roui., The purpose of the resistance is to apply a potential to the coils B and L which is higher than the normal voltage of the coils .



    This results in the dissipation of a certain current which. otherwise would be useful, but this does not matter besides the advantages resulting from the transfer speed.



   For example, if: the voltage drop on one and the other of the coils is 80 volts, as it is indicated then, with the 40 volts applied to the resistance R, we will have in all 120 volts, that is to say on B and R is on L and R. Usually, B and L can have the same resistance. Assuming that a current of two amperes passes through the system
 EMI15.10
 Bi R or the system la, Ri, it is clear that before this current begins to flow a potential of 120 volts is applied to L or B as appropriate, This abnormally high voltage reduces the time constant of the coil L or B so that the magnetization time is significantly reduced,

   It is thus seen that the load resistance R becomes a means to accelerate the full magnetization after the charge transfer has occurred, Dams the example visible in fig. 5.resistance

 <Desc / Clms Page number 16>

 total of a load L and R (for example) is 60 ohms with 40 ohms on L and 20 ohms on R. With 120 volts, 11 will pass two amps * The -'Watts lost in the coil L will be 160 and in the resistance R, of 80. This loss is compensated functionally by the accelerated transfer.



   The term "brake" is to be understood as meaning any apparatus having a resistive effect on a controlled member and it includes devices such as dynamometric elements AD and B-1 of FIG. 4 as well as items such as BR and B from fig 1.


    

Claims (1)

CLAIMS. 1 - A transfer mechanism for adjusting the operation of clutches, brakes, magnetic slip dynamometers or other similar devices. This mechanism comprising a driving member, actuates a driven member by means of an electric coupling or clutch and an electric brake with means responsive to the speed of the driven member to actuate the coupling or the 'clutch and brake. 8 - A mechanism according to claim 1 and comprising a generator mounted on the driven shaft and controlling the operation of the coupling and the brake. 3- A mechanism according to claim 2 and wherein an electronic circuit controlled by the generator, tightens the electrical coupling in response to the drop in speed of the driven member and energizes the brake in response to the increase in speed of the same organ. 4. A mechanism according to claim 3 and in which a bridge circuit is used to prevent sudden variations in the application of energy using either the coupling or the brake. 5 - A mechanism according to the preceding claims and having a potentiometer for predetermining by hand the speed of the driven member above which the brake comes into action and below which the driving power is applied. 6- A mechanism according to claim 5 and wherein the electronic circuit is characterized in that if the driven member begins to sepralemntir from a predetermined speed, the driving member exerts by means of the clutch, an action increased on the driven member thanks to the electrical excitation of the clutch, and by the fact that if the driven member starts to accelerate from said predetermined speed, a retarding force is applied to the driven member by energizing said brake, so as to keep the speed of the driven member substantially constant, the clutch having its excitation removed when the brake is energized and vice versa. 7 - A mechanism according to claims 3 and 5 and wherein the electronic circuit comprises an inductor winding energizing the clutch and a second inductor winding energizing the brake with rectifier tubes having a cathode, an anode and a grid for igniting the tube connected to the first winding when the speed starts to drop below a normal driven body speed, or to turn on the tube connected to the second winding when the driven body speed starts to increase. be above said normal speed, the potentiometer determining the value of the normal speed for any of the various values. 8 - A mechanism according to the preceding claims and having an adjustment voltage circuit supplied by the generator, a reference voltage circuit <Desc / Clms Page number 18> connected to the regulating circuit, a circuit for alternately energizing the windings and a voltage inversion bridge circuit connecting said regulating and reference voltages to said excitation circuit and arranged in response to the speeds of the generator below a predetermined value to cause the excitation of the first winding by suppressing that of the second, and EMI18.1 at higher generator speeds above said predetermined value to cause suppression of the excitation on the first winding and the excitation of the brake winding; circuits being provided for distributing current in one or the other following winding EMI18.2 vant 1 eacitation, 9 - A mechanism according to the preceding claims and in which a transfer circuit connects the EMI18.3 refezencs aircuit and the adjustment circuit with the excitation circuit so that variations in the speed of the driven member above an optimum value remove the power supply to the clutch winding and an excitation. progressive reduction of the brake winding, and that the variations in speed below said optimin value suppress the excitation in the brake coil and gradually establish the excitation of the 1 winding clutch. winding excitation EMI18.4 10 - A mechanism according to the preceding claims and in which the electronic circuit is controlled by an adjustment section supplied by the manager and having an adjustable connected section of voltage preferably and also a transfer section connected to the generator and a section of reference voltage responding to deviations EMI18.5 speed from dtum optimum value determines circuit speed deviations by: optimum value determined by the adjustment of the reference vehicle circuit, by the reference transportJS e transfer, the said transfer carrying 1 excitation from one of the other said windings and vice versa, n to the other the generator speed is above or below speed is above or below the optimum speed; means acting from the life are optimally set relatively low so as to achieve some excitation of the brake coil under the conditions of controlled excitation in the clutch coil. 11 - A mechanism according to claims pre- circuits and wherein the transfer circuit connects the tubes, responding reference and adjustment to the grids EMI18.6 of a corresponding to 1 increase in potential above a predetermined value in the control circuit µ. remove the grid from the potential clutch winding tube 1 which passes through it and responds to decreasing potentials in the tuning circuit below the predetermined value to bring the grid of the crossmember. brake to remove the current flowing through it. <Desc / Clms Page number 19> The - A mechanism according to the preceding claims and wherein the potentiometer is provided with a selector arm for determining relatively positive and negative potentials and connected to the cathode of the tube in the grein circuit, and in the adjustment circuit and to the grid of the last named pipe element. 15. A mechanism according to the preceding claims. And characterized by a rectifier tube without grill. Having a cathode connected to the secondary of a transformer an anode connected to a load coil, the tube without grid functions as a bypass of current in relation to the grid-regulated tube and to the secondary for the circulation of currents due to the inductive action of the charge coil when the grid-regulated tube is annihilated 14. A mechanism according to the preceding claims. And having direct current induotive load coils with a half-wave grid-regulated rectifier connected to each coil, an AC cathode supply transformer being provided for the two cathodes having a common connection with the two coils, the anodes of each tube being connected by separate secondaries of an anode transformer to the two coils and a gridless rectifier tube being connected to each grid-tuned tube so as to feed thereon and having a cathode supplied by the cathode supply transformer and the cathode being connected to one of the coils dump.