DE347534C - Device to prevent the formation of sparks at the current connection pieces of a shift drum - Google Patents

Description

\ ■■ (ISSUED
ON JANUARY 13, 1922

The invention relates to devices for preventing sparking the current connection pieces of a shift drum, by laying the current interruption an auxiliary switch in series with the switching drum. At a known facility this type is the crank with the auxiliary switch inevitably allied and the well-known facility suffers accordingly

ίο at the disadvantage that the crank handle very much becomes difficult to move as soon as the shift drum for reasonably large engine outputs is built. The invention aims, one also for relatively large performances to create useful device of the type mentioned, which is characterized by simple and functional design and is free from the stated disadvantages.

In the drawing, Fig. 1 illustrates the subject matter of the invention in part embodiments shown in section, while Fig. 2 shows the associated circuit diagram.

To the fixed current connection pieces a ^{2 of} a switching drum A provided with a hand crank a ¹ , two lines C and C ¹ connected to the poles of a direct current source, the armature B and the exciter winding S ¹ are in the manner shown in the drawing (Fig. 2) a main current motor B, B ¹ and series resistors JV, 'N ¹ and N ^{2 are} connected.

In the course of the line C connecting the switching drum A to the positive pole of the power source, there is the interruption point of an electromagnetic circuit breaker, the current connection pieces D and D ^{1 of} which are provided with horns d ~ and d * in the manner of a lightning rod. In the course of the line C there is also a magnet winding d ⁱ , which is designed as a blower coil for extinguishing the sparks or arcs occurring at the interruption point D, D ^X. Of the two current connection pieces D and D ^x , one, D ¹ , is attached to 4-5 the pot-shaped housing E (Fig. 1) of an electromagnet designed as a contactor, the magnet winding Ji ^{1 of} which is attached to the in the manner shown in Fig. 2 Lines C and C ^{1 is} connected. The other current circuit piece D of the circuit breaker D, D ¹ is articulated by means of a two-armed lever F, the pivot f ¹ of which is mounted on the housing E of the contactor, with a magnet core G guided in the housing £. On one arm of the Hebeis F , a tension spring H attached to the housing E engages, which seeks to approach the current circuit piece D to the current ^{circuit piece D 1.} A collar g ² prevents the magnetic core G from exceeding a certain stroke when the switch is opened.

In the housing J3, coaxially to the magnetic core G, an auxiliary magnetic core / provided with two collars i ^z and i ^{3 is} arranged, on the end of which protruding from the housing E a roller K is mounted. One with

their ends in each of a bores g ¹ and i ^{1 of} the two magnetic cores G and / laying compression spring M seeks to maintain the magnetic core / in the position shown, in which it is located inside the housing B with its collar i ³ against the magnet housing B applies. The relationships are chosen so that when the magnetic cores G and / with their collars g ² and i ^{z are} in contact with the housing jB, there is still a small air gap between the magnetic cores. The roller K is in engagement with a detent disk a ^a , which is attached to the crankshaft α ^{4 of} the shift drum A. The arrangement is such that in each case a position in which (as shown in Fig. 1) the roller K rests in a detent of the disk a ³ , a switching position of the shift drum A corresponds.

ao Inside the magnet winding E ¹ enclosed by the magnet housing B there is also a metal hollow cylinder E ² which surrounds the magnet cores G and / or which represents a damping winding consisting of a single, short-circuited turn.

If, as a result of a rotation of the crank α ^τ, the shift drum A begins to change from one switching position to another, the detent disk a ^{3 sitting on the crankshaft α 4} rotates, and the roller K is driven by a tooth of the detent disk a ³ under compression of the spring M. lifted out of their rest. The auxiliary magnetic core / the main magnetic core G of the contactor is approached. As a result of the resulting reduction in the air gap between the magnetic cores G and 7, the magnetic tensile force of the contactor 4.0 increases to such an extent that the tensile force of the spring H is overcome and the magnetic core G is drawn into the housing E up to its collar g ^2. The current connection pieces D and D ¹ are separated from each other 4-5, so that the current flowing through the lines C and C ^{1 is interrupted.} Any arc that occurs in the process is quickly torn off by the combined action of the horns d ² , d ³ and the blow-out coil ^{d 4.} Immediately after caused by the separation of the current end pieces D and D ¹ interruption of the current flowing in the lines C and ^C1-stream of the shift drum starts in the interior of the intended switching, z. B. a reduction in the voltage supplied to the motor B, B ¹ by connecting one of the resistors N to N ² . The occurrence of a spark on a part of the shift drum intended to pass the current on is excluded, since at the moment of the beginning of the changeover the entire shift drum A is already disconnected from the power source; is. The switching process in the shift drum

is finished and the shift drum Ά takes ι after what was said earlier, its new shift position: when the shift crank α ^τ and! so that the detent disk α ³ by one pitch; has turned.

When the current connection pieces D and D ^{1 are separated} , in addition to the lines C, C ^x , the magnet winding E ^{1 of} the contactor has also become de-energized. Nevertheless, the magnetic cores G and T do not immediately return to the position shown, because the disappearance of the magnetic tensile force is delayed by the hollow cylinder E ^{2 acting as a damper winding.} The magnetic cores G and / rather go under the action of the springs M and H only then again in their position shown in the drawing, and the current circuit pieces D and D ¹ accordingly only return to their contact position when after a rotation of the detent disc a ³ by one division the Schaltwalzet assumes its new switch position. At the moment of re-contact of the current circuit pieces D and D ¹ , the previously interrupted circuits are closed again and the shift drum A and the motor B ₁ B ¹ again flowed through by the current.

The main advantage of the device described over the known device consists in the avoidance of the mandatory connection between the crank handle and auxiliary switch. By arranging a contactor, the opening movement of which is triggered by a the shift drum positively connected organ is initiated, it becomes possible the Build shift drum for any large performance without making it difficult to operate would.

Another advantage is that the delay time of restarting by changing the smallest distance between the magnetic cores G and /, z. B. by interposed cardboard disks, can be regulated within certain limits.

Claims (2)

Patent Claims: i. Device for preventing the formation of sparks on the current connection pieces of a switching drum by laying the current interruption on an auxiliary switch lying in series with the switching drum , characterized in that an element (K, J) which can be driven by the switching drum (A) causes the magnetic pulling force of a contactor to move (E, E ¹ ) brings it into effect in such a way that that the Efilfsschalter (D, D ¹ ) is transferred to the switch-off position against the action of an energy store (H). 2. Device according to claim i, characterized in that the contactor (E, B ¹ ) has two coaxial magnetic cores (/, G) held apart by a spring (M) , one of which (G) with the movable current circuit piece (D) of the auxiliary switch ιό is inevitably connected and the other (/) is connected to the switching drum (A) in such a way that each rotation of the switching drum by one switching step results in a temporary approach of the two magnetic cores (G and /). 1 sheet of drawings.