GB1561558A

GB1561558A - Wiper motor

Info

Publication number: GB1561558A
Application number: GB19778/78A
Authority: GB
Original assignee: SWF Spezialfabrik fuer Autozubehoer Gustav Rau GmbH
Current assignee: SWF Auto Electric GmbH
Priority date: 1977-06-18
Filing date: 1978-05-16
Publication date: 1980-02-20
Also published as: FR2394739B3; DE2727452C2; DE2727452B1; IT7824441A0; FR2394739A1; ZA782888B; BR7803805A; ES244579U; ES244579Y; IT1096645B

Description

(54) WIPER MOTOR (71) We, SWF-SPEZIALFABRlK FUR AUTOZUBEHOR GUSTAV RAU GMBH, a joint stock Company organised under the Laws of Germany of Stuttgarter Strasse 119, 712 Bietigheim Bissingen, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to an electric motor housing comprising a cylindrical casing and a circular end plate fitting in and closing one end of the casing, the end plate being secured to the casing at a plurality of circumferentially spaced locations, there being at each location a pair of indentations in the casing wall, one on each side of the end plate, there being a gap between them which changes from a width greater than to a width less than the thickness of the end plate as one passes along the gap whereby the edge of the end plate is pinched in the gap by said pair of indentations.

A motor housing of the type mentioned above composed of a cylindrical casing and an end plate is used with advantage in cases where parts have to be installed in it from both ends, as, for example, is the case of a motor vehicle windscreen wiper motor.

Such a motor housing for instance is described in our British Patent Specification No. 1,503,203, and a connection between cylindrical casing and the end plate when the casing is drawn like a cup gives the best results. In comparison with it the connection between cylindrical casings rolled from a metal sheet and their end plates is not completely satisfactory.

Especially under shock conditions it happens again and again that the cylindrical casing bursts open.

It is the object of the present invention to obtain a reliable connection between an end plate and a cylindrical casing which is suitable also for rolled cylindrical casings.

According to one aspect of the present invention there is provided an electric motor housing comprising a cylindrical casing and a circular end plate fitting in and closing one end of the casing, the end plate being secured to the casing at a plurality of circumferentially spaced locations, there being at each location a pair of indentations in the casing wall, one on each side of the end plate, there being a gap between them which changes from a width greater than to a width less than the thickness of the end plate as one passes along the gap whereby the edge of the end plate is pinched in the gap by said pair of indentations, and wherein the indentation adjacent the one end of the casing is inclined at an agle to the longitudinal axis of the cylindrical casing such as to engage the radially innermost edge of the indentation adjacent the gap in the neighbouring surface of the end plate.

According to another aspect of the present invention there is provided a method of making an electric motor housing comprising providing a cylindrical casing having a plurality of slots in the wall thereof adjacent one cylinder end at circumferentially-spaced-apart locations, ' forming respective indentations on one side of each slot, fitting a circular end plate in the casing so that one side of the plate rests against the indentations to close one end of the casing, and subsequently forming at each said location a further respective inclined indentation on the other side of the slot thereat to secure the end plate, the gap between the pertaining indentations at each location changing from a width greater to a width less than the thickness of the edge of the end plate in progressing along the gap whereby the edge of the end plate is pinched in the gap by the pertaining indentations, the further respective indentations being inclined at an angle to the longitudinal axis of the cylindrical casing such that their radially innermost edges at the slots engage in the neighbouring surface portions of the end plate.

By inclining the indentation with respect to the casing and the end plate an additional force component is created vertically to the end plate and the edge of the indentation simultaneously claws in it. Thereby a connection is created which even with rolled housing portions has proved to be sufficient.

An inclination angle with respect to the longitduinal axis of the casing within the limits of 50 and 300 has proved to be especially useful. A further increase in the strength of the connection is achieved if the punched edge of the slot bounding the inclined indentation is designed at an angle to the outer wall of the casing which is larger than 909 An embodiment of the present invention will now be described with reference to the accompanying drawings, in which: Fig. 1 shows a section through a joint between an end plate and a cylindrical casing; Fig. 2 shows the joint of Fig. 1 partially sectioned and as seen from the interior of the casing, and Fig. 3 shows the joint of Fig. 1 as seen looking at the "open" end of the casing which is closed by the end plate.

An electric motor housing comprising a tubular casing 1, which is substantially cylindrical and made of a deformable material, has an open end which is closed by a substantially circular end plate 8. The casing encloses the stator (not shown) of a motor, whilst the end plate is adapted to support a bearing (not shown) of the motor.

The casing 1 can be rolled up from a metal sheet.

The end plate 8 is supported on and secured to the casing 1 at a plurality of locations (joints) around the circumference of the casing adajacent its open end. For each joint a slot-shaped opening 2 is punched out of the casing 1 in the edge zone adjacent the open end of the casing 1. The edge 3 of the slot may be Darallel to the periphery of the casing end when the slot is initially punched out, whereas the edge 4 is pitched or angled as shown. In the embodiment shown in Fig. 1 the punched edge 4 is at an agle 5 of 90 to the outer wall 6 of the casing 1. A possible enlargement of the angle 5 is indicated by the dash-dotted line 15.

The portion 7 of the edge 4 is spaced apart from the edge 3 by a distance greater than the thickness of the edge of the end plate 8, whereas the width of the slot at its ends such as 9 is less than the thickness of the edge of the end plate 8.

Associated with the slots 2 are portions of the casing such as 10 which are approximately triangular as shown (Fig. 2), and are deformed to project into the interior 11 of the casing 1, so that the edges 3 act as supports for the end plate 8 which is inserted from the open end of the casing.

Subsequently portions 12 of the casing 1 arranged between the slots 2 and the periphery of the casing end are deformed to project into the interior 11 of the casing (Figs. 1 and 3). This deformation is such that the portions 12 are at an angle 13 to the axis of the cylindrical casing 1. After a certain amount of deformation the edge 4 rests upon the end plate 8, and after further deformation of the portion 12 into the interior 11 of the casing 1, due to a force P appearing between the end plate 8 resting on the portion 10 and the portion 12, the portion 12 digs or claws into the end plate 8 via its radially-innermost edge 14 at the slot 2. The force P together with the counteracting force A create a connection between the end plate 8 and the casing 1 which is absolutely free from play and' resistant to high loads. The connection is sufficient even with rolled sheet metal casings. The enlargement 15 of the angle 5 shown in Fig. 1 serves to increase the strength of the connection between the end plate 8 and the casing 1 still further.

WHAT WE CLAIM IS: 1. An electric motor housing comprising a cylindrical casing and a circular end plate fitting in and closing one end of the casing, the end plate being secured to the casing at a plurality of circumferentially spaced locations, there being at each location a pair of indentations in the casing wall, one on each side of the end plate, there being a gap between them which changes from a width greater than to a width less than the thickness of the end plate as one passes along the gap whereby the edge of the end plate is pinched in the gap by said pair of indentations, and wherein the indentations adjacent the one end of the casing is inclined at an angle to the longitudinal axis of the cylindrical casing such as to engage the radially innermost edge of the indentation adjacent the gap in the neighbouring surface of the end plate.

2. An electric motor housing as claimed in claim 1, wherein the inclination angle is between 50 and 300.

3. An electric motor housing as claimed in claim 1 or 2, wherein the gap between the indentations is formed by a punched slot on the punched edge of the inclined indentation is at an angle to the outer wall of the casing which is greater than 900.

4. A method of making an electric motor housing comprising providing a cylindrical casing having a plurality of slots in the wall thereof adjacent one cylinder end at circumferentially-spaced-apart location, forming respective indentations on one side of each slot, fitting a circular end plate in the casing so that one side of the plate rests against the indentations to close one end of the casing, and subsequently forming at each said location a further respective inclined indentation on the other side of the slot thereat to secure the end plate, the gap between the pertaining indentations at each

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

An inclination angle with respect to the longitduinal axis of the casing within the limits of 50 and 300 has proved to be especially useful. A further increase in the strength of the connection is achieved if the punched edge of the slot bounding the inclined indentation is designed at an angle to the outer wall of the casing which is larger than 909 An embodiment of the present invention will now be described with reference to the accompanying drawings, in which: Fig. 1 shows a section through a joint between an end plate and a cylindrical casing; Fig.
2 shows the joint of Fig. 1 partially sectioned and as seen from the interior of the casing, and Fig.
3 shows the joint of Fig. 1 as seen looking at the "open" end of the casing which is closed by the end plate.

An electric motor housing comprising a tubular casing 1, which is substantially cylindrical and made of a deformable material, has an open end which is closed by a substantially circular end plate 8. The casing encloses the stator (not shown) of a motor, whilst the end plate is adapted to support a bearing (not shown) of the motor.

The casing 1 can be rolled up from a metal sheet.

The end plate 8 is supported on and secured to the casing 1 at a plurality of locations (joints) around the circumference of the casing adajacent its open end. For each joint a slot-shaped opening 2 is punched out of the casing 1 in the edge zone adjacent the open end of the casing 1. The edge 3 of the slot may be Darallel to the periphery of the casing end when the slot is initially punched out, whereas the edge
4 is pitched or angled as shown. In the embodiment shown in Fig. 1 the punched edge 4 is at an agle
5 of 90 to the outer wall
6. A method of making an electric motor housing substantially as herein described with reference to the accompanying drawings.

6 of the casing 1. A possible enlargement of the angle 5 is indicated by the dash-dotted line 15.

The portion 7 of the edge 4 is spaced apart from the edge 3 by a distance greater than the thickness of the edge of the end plate 8, whereas the width of the slot at its ends such as 9 is less than the thickness of the edge of the end plate 8.

Associated with the slots 2 are portions of the casing such as 10 which are approximately triangular as shown (Fig. 2), and are deformed to project into the interior 11 of the casing 1, so that the edges 3 act as supports for the end plate 8 which is inserted from the open end of the casing.

Subsequently portions 12 of the casing 1 arranged between the slots 2 and the periphery of the casing end are deformed to project into the interior 11 of the casing (Figs. 1 and 3). This deformation is such that the portions 12 are at an angle 13 to the axis of the cylindrical casing 1. After a certain amount of deformation the edge 4 rests upon the end plate 8, and after further deformation of the portion 12 into the interior 11 of the casing 1, due to a force P appearing between the end plate 8 resting on the portion 10 and the portion 12, the portion 12 digs or claws into the end plate 8 via its radially-innermost edge 14 at the slot 2. The force P together with the counteracting force A create a connection between the end plate 8 and the casing 1 which is absolutely free from play and' resistant to high loads. The connection is sufficient even with rolled sheet metal casings. The enlargement 15 of the angle 5 shown in Fig. 1 serves to increase the strength of the connection between the end plate 8 and the casing 1 still further.

WHAT WE CLAIM IS: 1. An electric motor housing comprising a cylindrical casing and a circular end plate fitting in and closing one end of the casing, the end plate being secured to the casing at a plurality of circumferentially spaced locations, there being at each location a pair of indentations in the casing wall, one on each side of the end plate, there being a gap between them which changes from a width greater than to a width less than the thickness of the end plate as one passes along the gap whereby the edge of the end plate is pinched in the gap by said pair of indentations, and wherein the indentations adjacent the one end of the casing is inclined at an angle to the longitudinal axis of the cylindrical casing such as to engage the radially innermost edge of the indentation adjacent the gap in the neighbouring surface of the end plate.

2. An electric motor housing as claimed in claim 1, wherein the inclination angle is between 50 and 300.

3. An electric motor housing as claimed in claim 1 or 2, wherein the gap between the indentations is formed by a punched slot on the punched edge of the inclined indentation is at an angle to the outer wall of the casing which is greater than 900.

4. A method of making an electric motor housing comprising providing a cylindrical casing having a plurality of slots in the wall thereof adjacent one cylinder end at circumferentially-spaced-apart location, forming respective indentations on one side of each slot, fitting a circular end plate in the casing so that one side of the plate rests against the indentations to close one end of the casing, and subsequently forming at each said location a further respective inclined indentation on the other side of the slot thereat to secure the end plate, the gap between the pertaining indentations at each

location changing from a width greater to a width less than the thickness of the edge of the end plate in progressing along the gap whereby the edge of the end plate is pinched in the gap by the pertaining indentations, the further respective indentations being inclined at an angle to the longitudinal axis of the cylindrical casing such that their radially innermost edges at the slots engage in the neighbouring surface portions of the end plate.

5. An electric motor housing substantially as herein described with reference to the accompanying drawings.