Title of Invention	A CENTRIFUGAL CLUTCH
Abstract	A centrifugal clutch for transmitting power driver means to driven means in an automobile comprising at least two clutch shoes mounted on a carrier plate assembly fixed on to the crank shaft of the engine of the automobile; a clutch housing freely floating on the crank shaft connected to the driven means to trasmit power to the driven means whenever the said clutch shoes engage with the housing, said clutch shoes being pivotably mounted on the carrier plate and held in position by springs, each said shoe being bonded with friction liner and incorporating an insert of higher density than that of the clutch shoe.

Title of Invention

A CENTRIFUGAL CLUTCH

Abstract

A centrifugal clutch for transmitting power driver means to driven means in an automobile comprising at least two clutch shoes mounted on a carrier plate assembly fixed on to the crank shaft of the engine of the automobile; a clutch housing freely floating on the crank shaft connected to the driven means to trasmit power to the driven means whenever the said clutch shoes engage with the housing, said clutch shoes being pivotably mounted on the carrier plate and held in position by springs, each said shoe being bonded with friction liner and incorporating an insert of higher density than that of the clutch shoe.

Full Text	Technical Field: This invention relates to a " Centrifugal Clutch" and more particularly to a . 'centrifugal clutch for transmitting power from the driver means to driven means for automobiles. Background: As known in the art, for a single speed automobile transmission application, a conventional centrifugal clutch is employed to transmit the dynamic torque of mechanical rotary power from drive shaft to a driven shaft through centrifugal action. In such; conventional centrifugal clutch types; power from the engine is transferred; from the . drive shaft to a clutch shoe, carrier assembly rotating along with the . drive shaft The carrier assembly is secured to the drive shaft using A my or spleens or by other known means. The clutch carrier assembly carries 2 or 3 identical mass shoes, which are pivoted thereon and on the outer cylindrical surface of each of which a friction liner is bonded. These clutch short are held at normal radial position with a spring or springs. When the engine runs at idling speed, the shoes are still at normal radial position, and do not Engage with the clutch housing. The clutch housing, which is freely floating on the crankshaft, is operatively connected to the driven shaft by known way so as to impart motion thereto. When the angular speed of crankshaft is increased due to increase in engine speed the centrifugal force experienced by each clutch shoe will lie increased. resulting in the extension of the clutch shoes against the spring force to engage with the clutch housing. Once sufficient centrifugal force has been imparted due to j still higher angular speed, the shoes fully engage with the clutch housing so that the housing rotates together with clutch carrier assembly thereby i , i transmitting the maximum possible part be engine torque to the housing which in turn drives the driven shaft through a gear or a chain drive, The speed at which the clutch engages with the housing depends upon the mass of each shoe, or with the position of its mass center and the spring force or the retaining moment of the spring force. When the speed reduces the clutch disengages from the housing thereby disconnecting the transmission. Hence depending upon the engine torque and sjpeed at which the maximum torque is produced, the weight of the clutch shoes and the spring rating are optimized so the shoes can transmit the engine torque at the desired speed to wheel without .any slipping. This torque carrying capacity Gf the clutch will change depending upon the rated engine torque and also the weight of the clutch shoes. In other words a clutch designed If or transmitting the maximum torque at a specific speed will not neqessarily work efficiently to transmit the higher i engine torque. Accordingly structural modification for increase the capacity of the centrifugal clutch is indispensable. £uch structural modification known in the art are; change in the outer* shape lof the clutch shoe, or change in the thickness thereof etc. Such structural modification can be said to be a natural choice, in view of,the fact that the base material of such conventional clutch shoe is a single homogenous material of high-density alloy. However the structural modification consisting in a change of the outer shape of the clutch shoe for the modification of the capacity of the centrifugal clutch leads to increase in the size of the centrifugal clutch, which is not appropriate selection in view of the arrangement o,f the clutch in the limited available space. Further since the increase in weight of the high density alloy will increase the material cost. Adding to this here is a limitation to increasing the density of the alloy. Accordingly there is a demand for an appropriate measure of increasing the Clutch capacity for transmitting torque without increasing the size of the centrifugal clutch and cost. Objects of Invention: The present invention relates to an improvement of the centrifugal clutch for solving the above-mentioned problems, and particularly to an improvement of the clutch shoe weight. Another objective of the invention to use! thecavailable space to provide a clutch, which has higher torque capacity. Another objective of the present inventionjis to provide a clutch capacity with lower cost. The accompanying drawings illustrate by Way of example and not by way of limitation one of possible embodiments of the centrigugal clutch proposed herein, Fig. 1 illustrating sectional view of clutch shoe with housing Fig. 2 illustrating the clutch shoe at View X in Fig. 1 without housing Fig. 3 illustrating the clutch shoes with metal insert Two clutch shoes C mounted on a carrier plate assembly A fixed on to the crank shaft of the engine of the automobile. A clutch housing H freely floats on the crank shaft connected to the driven means to transmit power to the driven means whenever the said clutch shoes engage with 1he housing. The clutch shoes are pivotably mounted at P on the carrier plate and held in position by springs S. The outer cylindrical surface of each of the clutch shoes is bonded with friction liner F and incorporates an insert J of higher density than that of the cast alloy of which the clutch shoe is made. The insert has an aperture B formed in it for locating the same during casting. In view of the aforementioned arrangement the overall weight of the shoes is increased thereby increasing the torque carrying capacity, while not increasing the size of the clutch. We Claim: 1 A centrifugal clutch for transmitting power from driver means to driven means in an automobile comprising at least two clutch shoes mounted on a carrier plate assembly fixed on to the crank shaft of the engine of the automobile; a clutch housing freely floating on the crank shaft connected to the driven means to transmit power to the driven means whenever the said clutch shoes engage with the housing, said clutch shoes being pivotably mounted on the carrier plate and held in position by springs, each said shoe being bonded with friction liner and incorporating an insert of higher density than that of the clutch shoe. 2. A centrifugal clutch as claimed in Claim 1 wherein the insert has at least two apertures formed in it for locating the same during casting. 3. A centrifugal clutch as claimed in Claim 1 or Claim 2 wherein the said inserts are made by sheet blanking or laminating sheets joined together. 4. A centrifugal clutch substantially as herein described with reference to, and as illustrated in, the accompanying drawings.

Full Text

Technical Field:
This invention relates to a " Centrifugal Clutch" and more particularly to a
. 'centrifugal clutch for transmitting power from the driver means to driven
means for automobiles.
Background:
As known in the art, for a single speed automobile transmission application, a
conventional centrifugal clutch is employed to transmit the dynamic torque of
mechanical rotary power from drive shaft to a driven shaft
through centrifugal action. In such; conventional centrifugal clutch types;
power from the engine is transferred; from the . drive shaft to a clutch shoe,
carrier assembly rotating along with the . drive shaft The carrier assembly is
secured to the drive shaft using A my or spleens or by other known means.
The clutch carrier assembly carries 2 or 3 identical mass shoes, which are

pivoted thereon and on the outer cylindrical surface of each of which a friction
liner is bonded. These clutch short are held at normal radial position with a
spring or springs. When the engine runs at idling speed, the shoes are still at
normal radial position, and do not Engage with the clutch housing. The clutch
housing, which is freely floating on the crankshaft, is operatively connected to
the driven shaft by known way so as to impart motion thereto. When the
angular speed of crankshaft is increased due to increase in engine speed the
centrifugal force experienced by each clutch shoe will lie increased. resulting
in the extension of the clutch shoes against the spring force to engage with
the clutch housing. Once sufficient centrifugal force has been imparted due to
j

still higher angular speed, the shoes fully engage with the clutch housing so that the housing rotates together with clutch carrier assembly thereby
i , i
transmitting the maximum possible part be engine torque to the housing which in turn drives the driven shaft through a gear or a chain drive, The speed at which the clutch engages with the housing depends upon the mass of each shoe, or with the position of its mass center and the spring force or the retaining moment of the spring force. When the speed reduces the clutch disengages from the housing thereby disconnecting the transmission. Hence depending upon the engine torque and sjpeed at which the maximum torque is produced, the weight of the clutch shoes and the spring rating are optimized so the shoes can transmit the engine torque at the desired speed to wheel without .any slipping. This torque carrying capacity Gf the clutch will change depending upon the rated engine torque and also the weight of the clutch shoes. In other words a clutch designed If or transmitting the maximum torque
at a specific speed will not neqessarily work efficiently to transmit the higher
i
engine torque. Accordingly structural modification for increase the capacity of the centrifugal clutch is indispensable. £uch structural modification known in the art are; change in the outer* shape lof the clutch shoe, or change in the thickness thereof etc. Such structural modification can be said to be a natural choice, in view of,the fact that the base material of such conventional clutch shoe is a single homogenous material of high-density alloy.
However the structural modification consisting in a change of the outer shape of the clutch shoe for the modification of the capacity of the centrifugal clutch leads to increase in the size of the centrifugal clutch, which is not appropriate

selection in view of the arrangement o,f the clutch in the limited available space. Further since the increase in weight of the high density alloy will increase the material cost. Adding to this here is a limitation to increasing the density of the alloy. Accordingly there is a demand for an appropriate measure of increasing the Clutch capacity for transmitting torque without increasing the size of the centrifugal clutch and cost.
Objects of Invention:
The present invention relates to an improvement of the centrifugal clutch for
solving the above-mentioned problems, and particularly to an improvement of
the clutch shoe weight.
Another objective of the invention to use! thecavailable space to provide a
clutch, which has higher torque capacity.
Another objective of the present inventionjis to provide a clutch capacity with
lower cost.
The accompanying drawings illustrate by Way of example and not by
way of limitation one of possible embodiments of the centrigugal
clutch proposed herein,
Fig. 1 illustrating sectional view of clutch shoe with housing
Fig. 2 illustrating the clutch shoe at View X in Fig. 1 without
housing
Fig. 3 illustrating the clutch shoes with metal insert
Two clutch shoes C mounted on a carrier plate assembly A fixed on to the crank shaft of the engine of the automobile. A clutch housing H freely floats on the crank shaft connected to the driven means to transmit power to the driven means whenever the said clutch shoes engage with 1he housing.

The clutch shoes are pivotably mounted at P on the carrier plate and held in position by springs S. The outer cylindrical surface of each of the clutch shoes is bonded with friction liner F and incorporates an insert J of higher density than that of the cast alloy of which the clutch shoe is made.
The insert has an aperture B formed in it for locating the same during casting.
In view of the aforementioned arrangement the overall weight of the shoes is increased thereby increasing the torque carrying capacity, while not increasing the size of the clutch.

We Claim:
1 A centrifugal clutch for transmitting power from driver means to driven means in an automobile comprising at least two clutch shoes mounted on a carrier plate assembly fixed on to the crank shaft of the engine of the automobile; a clutch housing freely floating on the crank shaft connected to the driven means to transmit power to the driven means whenever the said clutch shoes engage with the housing, said clutch shoes being pivotably mounted on the carrier plate and held in position by springs, each said shoe being bonded with friction liner and incorporating an insert of higher density than that of the clutch shoe.
2. A centrifugal clutch as claimed in Claim 1 wherein the insert has
at least two apertures formed in it for locating the same during
casting.
3. A centrifugal clutch as claimed in Claim 1 or Claim 2 wherein the
said inserts are made by sheet blanking or laminating sheets joined
together.
4. A centrifugal clutch substantially as herein described with
reference to, and as illustrated in, the accompanying drawings.

Documents:

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Patent Number

269405

Indian Patent Application Number

613/CHE/2007

PG Journal Number

44/2015

Publication Date

30-Oct-2015

Grant Date

20-Oct-2015

Date of Filing

26-Mar-2007

Name of Patentee

TVS MOTOR COMPANY LIMITED

Applicant Address

JAYALAKSHMI ESTATES NO. 24 (OLD NO.8) HADDOWS ROAD, CHENNAI 600 006

Inventors:

#	Inventor's Name	Inventor's Address
1	KRISHNABHATTA NAGARAJA	RESEARCH & DEVELOPMENT, TVS MOTORS COMPANY LIMITED JAYALAKSHMI ESTATES NO. 24 (OLD NO.8) HADDOWS ROAD, CHENNAI 600 006
2	DEEPAK DAGADE	JAYALAKSHMI ESTATES NO. 24 (OLD NO.8) HADDOWS ROAD, CHENNAI 600 006
3	SRINIVASAN SAMPATH	JAYALAKSHMI ESTATES NO. 24 (OLD NO.8) HADDOWS ROAD, CHENNAI 600 006

PCT International Classification Number

F16D7/06

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA