DE2049020C2 - Hanging switch - Google Patents

Description

'"ζ" hanging switch according to claim 1, characterized in that the contact surfaces (a) are arranged at a shorter distance than the interrupting pins (b) from the driver shaft (8)''ι hanging switch according to claim 1, characterized in that the Drive shaft (8)

Polygon bar is. ^ ,. rrh

4. Suspension switch according to claim 1, characterized in that the cam disks (3, 4, a, o) ^ suspension switch according to claim 4, characterized in that the NockeitAeiben (3 4 5, b) on both sides of symmetry except for the contact ( a) and interruption areas (b) have one or more rest points (c) .

6. Pendant switch according to claim 1, characterized in that one of the on the driver shaft (8) arranged cam disk (4) with a Toothed ring (7) is provided for the connection to the slide switch (1). ,

7 slopes switch characterized according to claim 6., that the slide switch (1) is provided with a recess (Iaj for engagement of a two-armed shift lever (2). The above its axis of rotation (2ajmit its toothed segment (2b) mh the ring gear (7) of Cam disk (4) is in engagement

8 hanging switch according to claim 7, characterized in that the switching lever (2) in the Recess (IaJ of the slide switch (1) is rotatably and displaceably mounted.

9. Pendant switch according to claim 1./furch ap indicates that the cam disks (3,4,5, ft) Segments of a circle with an angle of about 90 dis Are 180 °.

10. Suspended switch according to claim 1, characterized in that each of the cam disks (3.4,

5, 6) is arranged in a separate switch housing (9). ,

11. Suspended switch according to claim 10, characterized in that each switch housing (9) has at least one recess (9b ) on one side and at least one projection (SaJ ) fitting into the recess (9b) on the other side.

12. Pendant switch according to claim 11, characterized in that each switch housing (9) has one or several through bores (10) for a haler according to claim 12 thereby t that the through hole (10) Sll (8) has a bearing stop

⁽¹ ° fUngehält according to claim 10, characterized in that itnnreichnet at the end of the HangeschalfetsrÄischaltgehäuse (9) with a cover!

^ according to claim 14 thereby

«Indicates that each pendant switch side erne Sr all switch housings (9) right Kontaktle.ste for the on both sides of the switch housing (9) p pressed by the spring (13) to produce the against the cam (A)

^ iiSiffiich claims 1 and 9, characterized in that. that the return springs £ 5 between the switch housing (9) and segment limiting surfaces (e) of the cam disc (3, 4, d,

3 °

35 ^ 5ärÄier according to claim 7, characterized in that the return springs (19) on the hubs (Q de, ^ «* ensch« ben. (3. 4, 5, 6) rotatably mounted strips (20) stirred are.

19 hanging switch according to claim 18, characterized in that the strips (20) m the The neutral position of the pendant switch is in contact with a stop (9c; of the switch housing (9).

The invention relates to a pendant switch with a plurality of 'slide switches' when actuated switch positions that can be achieved for controlling electric motors for hoists.

Due to legal regulations, a so-called dead man's circuit is required for hoists, which switches off the motor of the hoist when the operator does not turn the switch on of the possible control positions.

In the case of a pendant switch, the lower part is designed as a handle in which the slide switch is mounted. He depending on the desired direction of rotation of the electric motor, the thumb or a finger depressed. Such a pendant switch is easy to use, if not more than two switch positions, z. B. for lifting and lowering, are required. The possibility of incorrect control is with some Care excluded because the operator does not know the position of the hand encompassing the pendant switch needs to change. By pushing the slide switch harder, the Feinhub can be switched to normal stroke. To hold the slide switch in the switching stages, however, is a considerable effort required, which leads to fatigue of the operator.

It is also known to arrange several pressure switches in a common housing of a pendant switch. Such a pendant switch is not always recommended for controlling a hoist motor because the Operator mostly on a hoist

the hanging load is observed and the pressure switches are only actuated by feeling. Imprinting a wrong one Pressure switch is not excluded and leads to incorrect switching that can cause accidents. the The latter pendant switch is also so large that the operator can use it while switching must hold on with one hand while the other hand depresses the pressure switch. So it's not a hand for Guide the load hanging on a rope freely.

Various rotary switches with several cam disks are known, the contact surfaces of which are equally steep. Further, a Rastvo ^r is directional; -rg for an electrical rotary switch bek "·· 'f ng a steep and a flat contact surface \ \ _u' ■ Vsren cam differently steep .- · t η has Upon rotation of the cam plate. '.. A known electrical switching device has a lever which, when it hits an object via a shaft, rotates a cam disc with contact surfaces of different steepness, which actuates the plunger of a microswitch Dead man circuits.

In all known switches, one has due to the requirement for one of the operating speed the operator independent separation speed of the contacts a momentary switching in the type provided that a spring is biased over a certain actuation path, which when When a tipping point is exceeded, the contacts are suddenly separated or switched. Switches of this type have the disadvantage that the moving contacts have very high contact speeds occur, which with the relatively large mass of the contacts have a high kinetic energy cause which has an unfavorable effect on the bouncing behavior of the contacts. Reduce contact bruises the service life or increase the risk of wear and tear on the contacts.

The control of hoists is mostly a heavy load or mixed operation from heavy and normal loads. During heavy-duty operation, the motor's starting current is switched on and off, z. B. in tipping mode. At normal load, the starting current is switched on and the rated current of the motor is switched off. If the contacts become welded due to the high bounce times, this is the case with the known pendant switches not possible or only possible to a very limited extent, the contacts by introducing additional to open again to external forces. There is an increased risk of accidents if this is unintentional given control command can no longer or only belatedly be undone.

Cine Λ-citEre Risk of knowledge of the contacts and the course of the actuation force over the actuation travel thus creates a risk of accident. The well-known pendant switches have the characteristics of a helical spring in their force-displacement curve, i. H. steady increase in force up to the switching points. A spring is also pretensioned up to Tipping point at which the contacts are suddenly separated or switched. The tipping point is almost identical to the switching point. The preload of the spring results in a sinusoidal decrease in the Contact force until it becomes zero at the tipping point.

The object of the invention is to provide an easy-to-use pendant switch with a long service life several sound positions for controlling electric motors for hoists are created in which Incorrect switching due to carelessness or signs of fatigue on the part of the operator and by welded contacts are largely excluded. This object is achieved in that the Slide switch with several, arranged on a common drive shaft, differently shaped Cam disks is connected, the cam tracks with contact and interruption f'ä surfaces for rollers loaded by springs to actuate contact bridges and with between the contact and interruption surfaces are provided with differently steep contact surfaces for the rollers, and that return springs acting on the cam disks are arranged in the switch housing. Through the Different arrangement of the contact and interruption surfaces will make the roles of the different make contact surfaces driven back against the pressure of the springs to separate the contact bridges, or they are pressed into the recesses of the cam track and cause the Contacts.

The contact surfaces are narh another feature of the invention at a shorter distance than that Interrupting surfaces arranged away from the driver shaft. The number of cams will be determined by the number of desired switch positions.

The drive shaft can be a polygonal rod, preferably a square rod, which is of the Slide switch transmits initiated movement to all cam switches that are symmetrical. The contact surfaces are freely arranged with the various cams so that when you press the Slide switch usually only one spring is tensioned and the opposite one is relaxed. This is a easy operation of the slide switch guaranteed. The run-up surfaces can last before and after the dpr Switching step run so steep that even an inexperienced operator quickly notices when the last Switching stage is reached. The contact surfaces can also be designed so that the switching positions are powerless or can only be held with little force. This can be done by using some or all of the cams on both Symmetry sides apart from the contact and interruption surfaces have locking points.

When using the pendant switch according to the invention, incorrect switching due to carelessness or fatigue of the operator thanks to the physiologically favorable force-displacement curve of the Slide switch largely excluded.

According to a further feature of the invention is one of the cam disks arranged on the driver shaft provided with a ring gear for the connection to the slide switch, which has a recess for the A two-armed shift lever engages with its toothed segment above its axis of rotation with the. «Gear rim of the cam disk in engagement. The shift lever is in the recess of the Slide switch rotatably and displaceably mounted. With this arrangement, the displacement curve of the Shift lever can be selected from the point of view of ease of use.

According to other features of the invention, the cam disks are circular segments with an angle of approximately 90 to 180 °. Each of the cam disks is arranged in a separate switch housing and thus as a a structural unit can be produced, of which as required

several can be strung together. For this purpose, each switch housing has at least one recess on one side and at least one projection that fits into the recess on the other side. In addition, each switch housing has one or more through bores for one or more screws and for the drive shaft. In the case of suspension switches of different sizes, only the length of the screws and the drive shaft need to be adapted to the number of cam disks. The through-hole for the drive shaft can have a bearing stop, which is only required for the switch housing located on the end of a pendant switch. So all switch housings can be the same. The hl bfidlih Shlthä switch housing 9 protrude with their projections 9a in recesses 9b of the respectively adjacent switch housing. From FIG. 3 it can be seen that the pendant switch is also held together by two further screws 11 at the bottom on both sides. In this figure, the square driver shaft 6 can also be seen, which according to FIG. 1 is mounted at its ends via bearings 22 in the form of ball bearings in the outer switch housing 9 and the cover 12. The bearing 22 rests in the switch housing 9 on the bearing stop 10 a of the through hole 10. The driver shaft 8 is guided with a sliding fit through recesses g of the cam disks 3, 4, 5 and 6.

The introduction of the external force for actuation

is. ts can aiso aue ai'uaiigciiau » b · ^" - " ο .... ·. ^ _uo "."".—. _O

The switch housing 15 of the pendant switch located at the end of a pendant switch takes place via the slide switch i.

se can be provided with a cover that has the same through-holes as the switch housing for the screws and the drive shaft.

In the outer shell and the cover are

According to a further feature of the invention, bearings for toothed segment 2b located in the axis of rotation 2a are arranged in the drive shaft. The bearing of the ring gear 7 engages, which is a part of the cam disk

4 is. On each cam track 4 of the cam disks 3, 4,

of the pendant switch takes place via don S which is mounted in the protective housing 26 indicated by dashed lines. The slide switch 1 has a recess la for a switch lever 2 provided with a roller 2c , the above its

The driving shaft is therefore statically determined and only causes low frictional resistance. the The drive shaft is so strong that it can also be used in a pendant switch with many cam disks at the same time Occurrence of multiple impacts when switching does not sag.

According to an additional feature of the invention, each side of the pendant switch has a contact strip that extends over all of the switch housings for the contact bridge which is arranged on both sides of the switch housing and is pressed by the spring to establish contact against the cam track. This is connected to the roller that rolls on the cam track of the cam disk. The already mentioned return springs can be arranged between the switching housing and the segment boundary surfaces of the cam disks and attached to the. be guided on the hubs of the cam discs rotatably mounted strips. The strips in FIGS. 5 and 6 run from a roller 15 on each side, which is mounted in a slide 23. This is fixed on both sides in each switch housing 9 and carries a contact bridge 14, which is acted upon by a spring 13 in the direction of two contact strips 16 that are continuous over the entire length of the pendant switch. In FIG. 3 it can be seen that the unwinding of the rollers * 5 carrying the contact strips 14 on the cam track A ensures that the contacts are properly opened and closed.

Connection contacts 21 which are angled in such a way that they are parallel to the contact strips 16 run upper area run parallel to each other. At this part of each terminal contact 21 is. as in the F i g. 1 to 3 can be seen, a connecting disk 24 fastened by means of a socket head screw 25. The upper Area of the connection contact 21 is designed so that

stored ledges be tunn, uic i ^ ci ^ ti. m. ₆ <., i ... _u *. · *. »... ^ c ^ .. ^ ... uu.», ·. ».. *» ....... *> ^ —-Β--

the zero position of the pendant switch can be plugged onto a 40 commercially available plug

impact of the switch housing and thus limit the spring deflection of the return springs. Any return spring the opposing return spring only counteracts it until the zero position is reached.

The invention is explained in more detail with reference to the drawings

F 1 g. 1 a longitudinal section through a pendant switch,

2 shows the top view of FIG. 1,

Fig. 3 the section III-III through Fig. 1 through dashed lines indicated slide switch, switch lever and protective housing.

F i g. 4 schematically several cams in the various switch positions for two motor speeds,

have tightly spaced connection contacts 21 the advantage that they are clear and enable quick and perfect installation of the supply lines. Because of the continuous contact strips 16, there are additional connecting lines to the connection contacts 21 not required for many pendant switches and only partially required for others.

For cooling the arcing that occurs between the contact strips 16 and the during switching Contact bridge 14, cooling plates 18 are present. This increases the service life of the pendant switch The cooling plates 18 are resiliently clamped and can be retrofitted or for the Inspection of the contact bridges 14 and the contact lines

speeds, ■ ■ · --- 7

Fi e 5 the four cam disks are repeatedly dismantled to a larger extent.

To vary the actuation force

To vary the actuation force, the cam disks are located between the segment boundary surfaces e 3, 4, 5 and 6 and the switch housing return springs 19 inserted. They are in the upper part guided by strips 20, which are supported in the rest position on stops 9c of the switch housing 9 and on the hubs / the cam disks 3, 4, 5 and 6 are rotatably mounted. The hanging switch shown has

jcu uiiu uit ^^ ... vuv, ... each cam disc on each side a bar 20 and

According to FIG. 1, four identical disk-like 65 are a return spring 19. The strips 20 can also over Shift housing 9 in the upper area with a pass through all cam disks and from one or Passage bore 10 is provided for a screw 11 to which the several return springs 19 are acted upon. Switch housing 9 with a cover! 12 connects the From Fig.4 it can be seen that at the zero position

Rod,

F i g. 6 the calculated force-switching angle diagrams »Switch on« for the four cam disks,

F t g. 7 the calculated force-switching angle diagrams "Switch off" for the four cam disks,

F i g. 8 the characteristic curve of the return spring,

F i g. 9 the measured force / switching angle diagrams "Switch on" and "Switch off", resulting for the four cam disks and the return springs.

ne er Al M sii A B.

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urchmit
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supply ext. eten lhat

ment only the contacts actuated by the cam disk 3 by connecting the contact strips 16 via d'c contact bridge 14 are closed. In the first stage “lifting”, in addition to the contacts actuated by the cam disk 3, the right contact of the cam disk 4 and the left contact of the cam disk 5 are closed. Unintentional turning of the cam disks is prevented by the cam disks 4 and 5, in the locking points of which rollers, not shown in FIG. 4, engage. In the second stage, "lifting", the contacts of the cam disk 3 are open compared to the first stage and those of the cam disk 6 are closed. The roller then engages in the outer left locking point of the cam disk 4. In addition, the contact surfaces d of the cam disk 6 act as locking points against unintentional rotation in the direction of the zero position.

In FIG. 5, the different cam tracks A of the cam disks 3, 4, 5 and 6 can be clearly seen. All contact areas a have the same distance to the square openings g for the milnehmerwelle 8. The interruption areas b are also the same distance from the openings ^. The contact surfaces d of the cam disk 6 are flatter in the outer region than in the inner. The cam disks 4, 5 and 6 have pronounced locking points c. Since the cam disk 3 only causes the contacts to loosen in the second stage, it is wary that when the second stage is switched on, a greater resistance has to be overcome than when the first stage is switched on. Therefore, the contact surfaces d of the cam disk 3 are steep and act as one-sided latching stops dl in front of the output stage.

Due to the different design of the cam tracks A, it is possible to vary the switching program on the one hand and to configure the operating force and the actuation travel for operating the slide switch on the other hand in such a way that the electric motor can be controlled easily and with little fatigue and thus accident-proof.

In the F i g. 6 and 7 show the calculated force-switching angle diagrams for the four cam disks. The forces are plotted on the ordinates and the switching angles on the abscissas. It can be seen that e.g. B. to rotate the cam 6 in the direction of the first stage "lifting" because of the steep contact surfaces d as a limitation of the locking points c cumulative large forces have to be overcome. The rotation of the cam disks 4 and 5 causes lower resistance to drive up the roller 15, which is caused by the resistance running down to the contact surfaces a

ίο roles are reduced. For turning the cam disc 3 initially only rolling resistance has to be overcome. To overcome the rest areas the increases Theoretically, the shifting force rises suddenly and suddenly without changing the shifting angle.

The measured switching force resultant from the cam disks 3, 4, 5 and 6 is plotted in FIG. 8 is shown, / u is added to the individual forces. The F i g. 9 it can be seen that the switching force decreases as soon as the rollers 15 in the cam disks 4 and 5 have overcome the contact surfaces d and roll down into the locking points c or down on the contact surfaces d to the contact surfaces a . At the same time, the cam disk 6 causes low resistance because of the flat upper course of the contact surfaces d.

To switch to the second stage »lifting«, two steep contact surfaces d ^{must be overcome for df r} cam disk 3, and one flat contact surface c / each for cam disks 4 and 5.

The second stage is mainly held by the left latching point c of the cam disk 4. The outer left contact surface d 1 of the cam disk 3 makes it difficult to continue turning from the second stage "lifting", the contact surfaces d of the cam disk 6 make it difficult for the cam disks to return to the zero position.

From Fig. 9 also shows that the force curve when switching off is similar to when switching on However, the switching force to be applied by the operator is lower because it is controlled by the return spring 19 is supported.

In addition 5 sheets of drawings

609685/441

Claims (1)

or several screws (Π) and for taking ^{) t} Patent claims: 20th ,. Suspension switch with several switch positions caused by the recovery of a slide switch for controlling electric motors for hoists, characterized in that the slide switch (1) has several differently shaped cam disks (3, 4, 5, 3, 4, 5, 6) ιη is connected, the cam tracks (A) with contact (a) and interruption * laugh > (b) for rollers (15) loaded by springs (13) for actuating contact bridges (14) and with between the contact ( a) and interruption areas (b) arranged, different steüen contact surfaces (d) are provided for the role * and that in the switch housing (9) on the cam disks (3, 4, 5, 6) acting return springs (19) are arranged