DE464332C - Control for bucket and two-rope gripper winches - Google Patents

Description

GERMAN EMPIRE

ISSUED ON AUGUST 15, 1928

R EIC H S PATE NT OFFICE

PATENT LETTERING

CLASS 35 b GROUP

General Electricity Society in Berlin *)

Control for bucket and two-rope gripper winches

Patented in the German Empire on July 7, 1926

When operating the gripper, two motors are usually used, one of which is the closing rope and the other drives the tether drum. The two motors are among each other equal, and their total capacity is dimensioned for lifting the full grapple. When gripping and emptying, only the Closing cable motor switched on. The previously common control consists of two shift drums, of which only one is used for gripping and emptying, while for Raising and mostly also when lowering both shift drums are switched on. To at the Lowering of the open gripper despite various types of gripper A mechanical coupling can be used to achieve the same speed of the two motors as possible under load. which brings the two drums together when lowering. Man

So far, however, ao has not switched on the clutch when lifting, because two are mechanical Coupled motors easily become one when controlled by two different control units unequal power consumption are forced

The subject matter of the invention now avoids this inconvenience and ensures the same load in that both motors are switched on by the same control unit when lifting and lowering, while a second control unit is used for gripping and emptying. Compared to a known arrangement, where all the control movements, including the gripping and emptying may be controlled by a single roller, the new arrangement has the -part Before ¹ of freedom of movement with respect to the sequence of control movements, and the usability for all control modes. With the new control, each control unit and each side of the control can be provided with a circuit that best suits the particular purpose, whereas with the two-motor controls that have been used up to now, the control usually had to perform two different tasks . With the new control set up the control device for lifting and lowering in the first positions with three-phase current for cascade connection, with direct current for series connection, where, as is well known, two mechanically coupled motors only need half the current for half the speed simple starter circuit required for one motor alone. Only the simple starter circuit is used for emptying. In the previous controls, in which the control unit is also used for emptying, the so-called lowering force circuit with external regulation must be used in order to prevent excessive gripper lowering with direct current ng of the main current field can be used

*) The patent seeker indicated the following as the inventors: Dipl.-Ing. Carl Schiebeier in Berlin and Dr.-big. Walther Engel in Berlin-Lichterfelde *

those that, when used at the same time for emptying, consume unnecessarily high electricity which is greatly reduced with the new control.

Compared to a known gripper control with a planetary gear, the new Control has the same operational reliability and ease of use, but has a more favorable degree of efficiency, since the power-consuming piano rivet gear is no longer needed comes and is replaced by an ordinary clutch. There is also a special one coming Motor for grapple opening and emptying no longer necessary. The system costs are therefore lower, as is the power consumption becomes cheaper by avoiding the planetary gear.

The new control has the further advantage that it is not only for the gripper, but also can also be used for the bucket operation in the same way. Since it often happens that the same leader is on the the same crane has to work with both grab and bucket operation is uniformity valuable to the service.

Fig. 1 shows the arrangement of the gripper drive. m _t is the one with the tether drum, m ₂ is the motor that is connected to the closing part drum. ttih and m _s are the associated brake release magnets , ttik the magnet that releases the coupling between the motor shafts when switched on, while it is closed by weight or spring when the magnet is de-energized.

Fig. 2 shows an embodiment of the circuit, specifically for three-phase current. The control roller α is used for lifting and lowering. The upper part of the control drum switches the MOtOrWz ₁ and the associated brake magnet mn, the lower part the motor / K ₂ and the magnet m _s . The control roller b ar beitet only on the closing cable motor ιη ₂ and the magnet m _s and switches at the same time, the Entkupplungsmagneten rtik- While the control roller β on the lowering side on the first positions for counter-current braking and on the last positions for over synchronous sink set is, has the Control roller b only simple reverse circuit. By means of the control roller α , the motor Hi ₁ can only be switched on for lifting when the control roller b is in the zero position or in the first "gripping" positions. To achieve this, the circuit for the coil of the lifting contactor H ₁ for the motor m _i is guided via locking contacts d of the control roller δ, which are only closed in the positions ο and gripping 1,2. As a result, if the operator wants to switch on the tether motor m _x hi at the end of the gripping process, he must switch back to the zero position or to the first positions of the gripper control, -walzeö. The latter is necessary if he wants to go from gripping to lifting without interruption and want to prevent lifting of the gripper with the motor / K _{2 aEein.}

As soon as the gripper is hanging on both ropes, the driver switches the control roller δ to the zero position, the decoupling magnet m ^ is de-energized and the clutch closes. This is possible without a great deal of friction work and shock, since both motors have approximately the same speed. If the operator would erroneously switch the control roller α to "lower" while the control roller & is set to "gripping", there will be no disturbances in the circuit, since in the first positions of the control roller α the motors are not switched to lowering in the sense of force, but rather on brake circuit in the lifting direction. If emptying is to take place during lowering, control roller b is switched to "emptying" while control roller α is on "lowering".

In order to prevent the gripper from falling into the ropes when the magnet has released the holding rope brake and the clutch is released at the same time, a contact e is provided in the circuit of the uncoupling magnet m.] _T , which only ttih des Holding rope drive is closed. So you can only decouple when the brake m / _t holds the rope drum. Instead of direct switching, contactors can also be used for this blocking.

The control also allows a good distribution of the engine load. You can z. B. on the first or all lowering positions only turn on one motor, for example the tether motor m _v , which is not used when gripping and emptying. This also saves on magnetizing current, which improves the power factor, and requires fewer ohms, so you save on resistance material. If a lot is lowered with a full gripper, the closing cable motor will also be switched on, but only in the lowering force positions.

The control can be designed in a similar way for direct current, the control drum α then being provided with the known combined braking and power circuit. If you want to save energy with high power, you can set up the first positions of the control roller α for three-phase current for cascade connection, with direct current for series connection of the two motors.

You can increase funding - 120. sturag train the control in such a way that on the first positions the

Control wake α one motor is switched on alone and the last one is switched on alone, although the motors must be selected to be larger than the total power required to lift the full gripper. The motor switched on in the first positions must be designed for the power of the full gripper and the second is expedient for the

ίο Lifting the empty gripper with increased Measured speed. Is z. B. a three-phase asynchronous motor to lift the full gripper of 80 P. S. selected at 600 synchronous revolutions, the second motor is used to lift the empty gripper loaded with about 60 0/0 torque, and if it is used for 1000 synchronous revolutions If the connection is the same, the result is again a power of 80 P. S. With the same connected load for the network, however, the delivery rate is much higher. With this combination you can also use the Quick lowering regains more power because 1.66 times the speed with short-circuited Starting resistance is achievable. The transition from one engine to the other can be carried out in a known manner without interrupting the torque cause bumpless and overload the faster running Prevent motor.

Claims (5)

Patent claims: i. Control for bucket and two-rope gripper winches, the closing rope and holding rope drums of which are each driven by a special motor, characterized in that the two control devices are designed so that one (a) is only used for lifting and lowering and both motors are used simultaneously controls, while the other (&) alone controls the motor for driving the closing cable drum when gripping and emptying. 2. Controller according to claim 1, characterized in that the stroke positions of the a control unit (ß) only in the zero position or one of the first positions of the other control device (δ) set to »gripping« can be switched on. 3. Control according to claim 1, characterized in that the two motors are designed for different speeds and the slower running at first, the faster running one on the last positions of the first control device (ß) is switched on. 4. Control according to claim 1, characterized in that on all or part of the lowering positions of the control roller (ö) only one of the two motors, for. B. the tether motor (tn-i) is turned on. 5. Control according to claim 1, characterized in that the control roller (ß) on the first positions with three-phase current for cascade connection, with direct current is set up for series connection. 1 sheet of drawings