DE2724754C2 - Brush holder with screw cap - Google Patents

Description

The invention relates to a brush holder with a screw cap according to the preamble of the patent claim.

Such a brush holder is known from US Pat. No. 2,449,764. With this brush holder the U-shape of the contact plate formed by two guide lugs connected to one another via a yoke. At the yoke flat tongues are formed at right angles to the guide tabs as contact parts that are attached to come to rest on the face of the guide sleeve. Through the guide tabs that are slightly spread outwards the contact plate should be clamped to the guide sleeve so that the screw cap after the Insertion of the carbon brush can be screwed on without difficulty. When inserting the guide brackets into the guide shaft, these must be due to the expansion are slightly compressed so that they are even introduced into the guide shaft can. In practice, however, it has been shown that the guide tabs are often compressed too much and then no longer have enough tension to counteract the force of the coil spring against the contact plate to hold securely on the guide sleeve. The guide tabs are used in the known brush holder only the holder of the contact plate, thus only represent a holding part and not a contact part.

From US-PS 33 13 966 a brush holder is known in which a dovetail cap is pushed onto the trapezoidal widened end of the guide sleeve. This way the cap becomes held by positive locking on the guide sleeve.

The invention is based on the object of designing a brush holder so that one of the spring pressure with Safety withstanding clamp connection / wipe the guide sleeve and the Kontakf.cil of the Kontukbleche is achieved.

The solution of the given task ('dings me the Invention by the features specified in the characterizing part of the claim.

The yoke connecting the two legs is pressed outwards by the helical spring, whereby the legs are pressed accordingly firmly against the guide sleeve. Due to the resilient Curvature of the yoke increases the contact pressure. In addition, such a bulge can cause manufacturing inaccuracies be balanced because of it

ίο indenting the bulge the distance between the both legs is changed and the two legs thus also with imprecise manufacture of the Kontaklblechcs can be pushed over the end of the guide sleeve in any case.

i ^r ) The subject of the application is described in more detail below with the aid of an embodiment shown in the drawing. It shows
F i g. 1 a U-shaped contact plate,
2 shows the arrangement of a contact plate together with a spiral spring and carbon brush,

F i g. 3 shows a view of the arrangement according to FIG. 3 rotated by 90 °. 2,

F i g. 4 a complete brush holder.

The contact plate 1 shown in Fig. 1 is U-shaped and the yoke 4 connecting the two legs 2 and 3 is arched outward. A guide 5 for a spiral spring is also provided on the yoke. By d '_; e curvature of the yoke 4, the contact plate 1 receives a certain elasticity, through which the up-

This makes it easier to press the contact plate 1 onto a guide sleeve of the brush holder. Also will due to this curvature, better pressing of the legs 2 and 3 against the guide sleeve of the brush holder reached because the yoke 4 after pressing the

! 5 contact sheet 1 springs back again and thus the presses both legs 2 and 3 against the guide sleeve.

Rei the arrangement according to FIG. 2 and 3 is the contact plate 1 connected in an electrically conductive manner to a carbon brush 7 via a stranded wire 6. Between the contact plate 1 and the carbon brush 7 a spiral spring 8 is clamped through which the carbon brush 7 after insertion is pressed into the guide sleeve of a brush holder against the collector of the electrical machine. That Contact sheet 1 has in the case of FIG. 2 and 3 arrangement shown opposite the legs 2 and 3 around Guide tabs 9 and 10 offset by 90 °. These guide tabs 9 and 10 grip when the carbon brush is inserted into the guide sleeve also into the guide sleeve and thus lead the contact plate 1 at

so pushing on. This facilitates the assembly of the contact plate.

In the case of the FIG. The brush holder shown in FIG. 4 is the carbon brush 7 with the spiral spring 8 and the contact plate 1 inserted into a guide sleeve 10. The guide sleeve 10 itself is surrounded by an insulating body 11, by which the brush holder is isolated from the machine housing 12. On the insulating body 11 is a screw cap 13 is screwed on. The carbon brush 7 is pressed against the collector 14 by the spiral spring 8

bo an electric machine pressed. As from the representation can be seen, the two legs 2 and 3 overlap the axially protruding end of the guide sleeve 10. Due to the spring action of the outwardly curved yoke 4, the two legs 2 and 3 are against

fv "> the guide sleeve 10 is pressed. Nc '.; en a good Clamping connection is thereby also a good electrical contact for the Slri> intranstrans; i} 'unj! achieved. the Sironi überlragung achieved via a .in the lülinirigs-

sleeve 10 connected line 15, the two legs
and 3 as well as with the Koniaktblech 1 and the
Carbon brush 7 connected pigtail 6.

1 sheet of drawings

2 (1

30th

40

^r i0

bO

Claims (1)

Claim: Brush holder with screw cap, with one on top of the screw cap in an insulating body facing side from this axially protruding guide sleeve for a carbon brush is arranged, which is coupled with one end to one end of a helical spring and with a pigtail is connected, which inside the coil spring to one at the other end of the coil spring adjacent U-shaped contact plate is guided, which has a transverse to the axis of the guide sleeve running and lying in front of the end face of the guide sleeve contact part, which Konlaktblech also stand in electrical contact with the guide sleeve and on the guide sleeve can be clamped, characterized in that that the contact part of the contact plate (t) is U-shaped and that the two Legs (2 and 3) connecting yoke (4) of the U-shaped contact part is curved outward, that further the two axially protruding from the insulating body (11) Guide sleeve (10) on two opposite sides overlapping legs (2 and 3) are pressed against the guide sleeve (10) by the spring action of the curved yoke (4).