STRAP OVER INSULATING TIMER HOUSING FOR GROUNDING A MOTOR

TRESSE DE MISE A LA TERRE POUR MINUTERIE DE MOTEUR A BOITIER ISOLANT

English Abstract

STRAP OVER INSULATING TIMER
HOUSING FOR GROUNDING A MOTOR
Abstract of Disclosure
A metal strap is connected to a metal motor housing and to a
metal mounting plate for a timer having an electrically insulative
housing and which carries the motor to electrically ground the
motor to the mounting plate.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a combination of a timer and motor carried by a housing
for said timer and driving same, said housing being made from an
electrically insulative material, a means to electrically ground said
motor comprising:
(a) a metal strap,
(b) securing means securing an end of said strap to a housing
for said motor including spring tabs lanced from said strap
and engaging said housing for said motor and an aperture in
said end engaging a dimple protruding from said housing for
said motor, and
(c) a fastener securing another end of said strap to a timer
mounting plate carried by said housing for said timer.
2. In the combination according to claim 1 wherein said metal strap
conforms to an outer shape of said housing for said timer.

Description

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Generally speaking, the present invention pertains to a combi-
nation of a timer and a motor carried by a housing for the timer and
driving same, the housing being made from an electrically insulative
material, a means to electrically ground the motor comprising a metal
strap, securing means securing an end of the strap to a housing for the
motor, including spring tabs lanced from the strap and engaging the hous-
ing for the motor and an aperture in the end and engaging a dimple
protruding from the housing for the motor, and a fastener securing
another of the strap to a timer mounting plate carried by the housing for
the timer.
As well known in the timer art, electrical motors, such as
synchronous motors, are used in combination with timers to drive the
timer, the timer thèn being used to actuate devices according to a
programmed sequence. An example of such combination is a motor used
to drive a timer which in turn controls sequentially the elements
of an appliance such as a dishwasher.
Because of the electric current being used by the motor and
the timer it is essential that both the timer and the motor be
electrically grounded. In the case of the timer, it is usually grounded ii
through a mounting plate which mounts the timer to the appliance. In
the case of the motor, it is usually grounded through a lead wire
connecting the motor to the timer. Because of safety reasons, pains ;
must be taken to insure that such connections are securely made and
therefore this method of grounding the motor is costly.
Accordingly it is a feature of the invention to provide a
means to electrically ground an electric motor which is used in combi-
nation with d timer. Another feature of the inventlon is to provide such
a means which is relatively inexpensive. Another feature of the invention
is to provide a means of electrically grounding a motor to a mounting
plate for a timer carrying the motor through a metal strap. Yet another
feature of the invention is to provide such a metal strap which is secured
at one end to the motor through spring tabs engaging a housing for the
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motor and at another end through a fastener. Still another feature of the
invention is the provision of such a metal strap wherein the strap is
additionally secured at the spring end through an aperture in the strap
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engaging a dimple extending from the motor housing. These and other
features of the invention will become apparent from the following des-
cription taken in conjunction with the accompanying drawings wherein:
Figure 1 is an exploded pictorial view showing a motor and a
timer utilizing the invention; and
Figure 2 is a side view of the motor timer combination of Figure
1 with portions thereof being removed.
Referring now to the drawings there is shown a timer 10 carrying
a motor 11. This combination is well known in the industry and therefore
will not be described in detail. Suffice it to say that the usual
timer includes a housing 12 in which are carried rotatable cams and
switching means which open and close in response to the cams rotation to
open and close electrical circuits to devices or elements to be actuated,
the currents being completed through electrical terminals 14. Typical
of such timers is that disclosed in U. S. patent 3,582,582 issued June
1, 1971 to Kurt Pauker, et al. Motor 11 is generally of the synchronous
type and for the purposes of the invention includes a gear reduction
means enclosed in a housing 15, the rotor, stator, and energizing means
of the motor being encased in housing l6, the two housings together ~
providing a complete housing 18 for the motor. The above noted U. S. ;
3,582,582 references a synchronous motor and illustrates its connection
to a timer. The details of a synchronous motor for which the present
invention could be used is described and illustrated in U. S. patent
3,676,725 issued July 11, 1972 to Joseph E. Wiser, et al.
In accordance with the present invention, motor 11 is electrically
grounded to timer mounting plate 20 through a metal strap 22. The metal
strap lS secured to the motor housing 18 through a first securing means 24
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and to the mounting plate through a second securing means 26. First
securing means 24 includes spring tabs 28 and 30 which are lanced from an
end of the strap. Such tabs engage an edge 32 to hold the end in place.
First securing means also includes an aperture 34 in the same end of the
strap which engages a dimple 36 protruding from the motor housing.
Second securing means 26 includes a fastener such as a screw
38 extending through an'aperture 40 provided in boss 41, in the opposite
end of the strap and threading through an aperture 42 into the timer
'housing 12. The opposite end also includes a tab which is bent over boss
41 to further aid i'n holding the strap in place.
~- As shown, when the metal strap is in'place it conforms to the
outer shape of the housing for the timer.
' As is well known in the art, the timer with the motor is
mounted to a plate 44 through'mounting plate 20 and fastener 46, plate
- 44 being a structural element of an appliance.
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