Title of Invention

A GENERAL PURPOSE D.C MOTOR

Abstract

A general purpose d.c. motor having permanent magnets. brush and commutator assembly. comprising a motor housing provided with a first end for electric power supply and a second end for mechanical power take off. characterised in that the first end has an insulated cap irrem ovably fixed to the housing. the electric power supply leads being connected to term inals partly embedded in the cap and partly passing into the interior of the housing for connection to the brush and commutator assembly.

Full Text

This invention relates to a general purpose permanent magnet d.c. motor. At one end of the said motor is the mechanical power take off, while the other end receives electric power supply. In the known d.c. permanent magnet general purpose motor, the end which receives electric power supply has a removable insulated cap which fits on to the motor housing in a snap fit. The cap has electrical power supply connectors which, when the cap is fitted to the housing, come into electrical contact with terminals provided on the exterior of the housing, to supply electric power to the interior of the motor housing, that is, to the brush-commutator assembly. The known arrangement described above is cumbersome. Electrical contact is established through one set of terminals on the exterior of the housing and another set of terminals inside the cap. Having the terminals on the exterior of the housing results in the accumulation of dust and dirt thereon. Frequent removal of the cap and re-fixing thereof on to the motor housing, for maintenance purposes, ultimately creates a loose fit between the terminals and consequently poorer performance. This invention therefore proposes to eliminate or, at least greatly minimise the above mentioned drawbacks associated with the known motor by reason of the construction defined below. The general purpose d.c. motor having permanent magnets, brush and commutator assembly, according to this invention, comprises a motor housing provided with a first end for electric power supply and a second end for mechanical power take oif, characterised in that the first end has an insulated cap irremovably fixed to the housing, the electric power supply leads being connected to terminals partly embedded in the cap and partly passing into the interior of the housing for connection to the brush and commutator assembly. One of the modes of making the cap integral with the housing is to crimp the former to the latter. This invention will now be described with reference to the accompanying drawings which illustrate by way of example, and not by way of limitation, one of possible embodiments of the motor proposed herein Fig. 1 illustrating a known general purpose motor And Fig. 2 illustrating the embodiment above referred to. Referring to Fig. 1 the motor known to the art will be seen to have a motor housing HI provided with a first end El for electric power supply md a second end E2 for mechanical power take off The first end El is provided with a removable insulated cap CI which forms a snap fit with the housing at T. One end of the electric power supply terminals of the motor are connected to the brush-com mutator assembly within the housing HI and the other end of the terminals J are located outside the housing. The electric power leads LI for supplying power to the motor come into electrical contact with the terminals J when the cap is closed over the housing in a snap fit and thus electric power to the motor is established. However, such electrical contact is a "touch" contact and can work itself loose over passage of time, as the cap is removed and fitted back, from time to time, for maintenance and other purposes. Loosening of contact cm lead to sparking and other undesirable results. Referring to Fig.2 the motor housing H2 is provided with a first end Ell for electric power supply and a second end E22 for mechanical power take off. The first end Ell has an insulated cap C2 irremovably fixed to the housing H2. The electric power supply leads L2 are connected to terminals J2 ptu'tly embedded in the cap and partly passing into the interior of the housing H2 for connection to the brush and commutator assembly. The electrical contacts are therefore no longer "touch" contacts and cannot work themselves loose inasmuch as the cq) is not removable. Consequently, no sparking resulting from loose contacts can arise. Electric terminals are no longer exposed and the entire assembly is m integral unit. One of the modes of making the cap integral with the housing is to crimp the former to the latter.WV ^. The terms and expressions herein are of description and not of limitation, since various embodiments of the motor proposed herein are possible without departing from the scope and ambit of this invention. We Claim: L. A general puq)Ose d.c. motor comprising permanent magnets, brush and commutator assembly, and a motor housing provided with a fu-st end for electric power supply and a second end formechanical power take off characterised in that the first end has an insulated ct^ irremovably fixed to the housing, the electric power supply leads bemg connected to term inals partly embedded in the c^ and partly passing into the interior of the housing for connection to the brush and commutator assembly. 2. A general purpose d.c. motor as claimed in Claim 1 wherein the cap is crimped to the housing to irremovably fix the former to the latter. 3. A general purpose d.c. motor substantially as herein described with reference to, and as illustrated in, Fig. 2 of the accompanying drawings.

Documents:

450-che-2004-abstract.pdf

450-che-2004-claims duplicate.pdf

450-che-2004-claims original.pdf

450-che-2004-correspondnece-others.pdf

450-che-2004-correspondnece-po.pdf

450-che-2004-description(complete) duplicate.pdf

450-che-2004-description(complete) original.pdf

450-che-2004-drawings.pdf

450-che-2004-form 1.pdf

450-che-2004-form 19.pdf

450-che-2004-form 26.pdf