Claims
- 1. In a conical camstack of the type having a hub rotatable about a central axis, the improvement comprising cam means for opening and closing a plurality of switches in a direction at an angle to said central axis and to the lines normal to said central axis.
- 2. A camstack comprising:
- a first cam surface aligned along a first cone formed about a central axis of revolution of said camstack, wherein a projection of a locus of points from said first cam surface forms a first included angle with said central axis of revolution at a first vertex;
- at least one other cam surface aligned along a second cone formed about said central axis of revolution, wherein a projection of a locus of points from said one other cam surface forms a second included angle with said central axis of revolution at a second vertex; and
- surface means for connecting portions of said first cam surface and portions of said one other cam surface to provide cam lobe means for opening and closing an electrical switch in a direction at an angle to said central axis and to the lines normal to said central axis.
- 3. A camstack comprising:
- a first cam surface aligned along a first cone formed about a central axis of revolution of said camstack, wherein a projection of a locus of points from said first cam surface forms a first included angle with said central axis of revolution at a first vertex;
- at least one other cam surface aligned along a second cone formed about said central axis of revolution, wherein a projection of a locus of points from said one other cam surface forms a second included angle with said central axis of revolution at a second vertex; and
- surface means for connecting portions of said first cam surface and portions of said one other cam surface to provide cam lobe means for opening and closing an electrical switch at an angle normal to said first and one other cam surfaces.
- 4. A camstack according to claim 3 wherein the projection of said first cam surface and the projection of said one other cam surface are equidistant between each other along their lengths.
- 5. A cam-switch assembly comprising a camstack as recited in claim 3 and switch means for engaging said cam surfaces provided by said camstack to be opened and closed thereby.
- 6. A timer comprising:
- a support;
- a camstack mounted on said support and rotatable about an axis of rotation;
- means for rotating said camstack about said axis;
- electrical switch means mounted on said support; and
- cam means on said camstack for opening and closing said electrical switch means in a direction at an angle to said axis and the lines normal to said axis.
- 7. A timer as in claim 6 wherein said cam means includes a plurality of cam surfaces and wherein a projection of points along one cam surface and intersecting said axis is parallel to a projection of points along another cam surface and intersecting said axis.
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of application Ser. No. 07/048,497, filed 05-08-87 now abandoned, which was itself a continuation-in-part of application Ser. No. 06/932,606, filed 11-20-86, now abandoned.
The present invention relates to a camstack and more particularly to a camstack that is useful for actuating individual switches that are carried by a single common support.
Camstacks of the type of the present invention are used extensively in timing mechanisms to open and close electrical switches which in turn make and break electrical circuits to an appliance to control the appliance's functions. As the operation of appliances becomes more complicated, the need for more control cycles on the camstack becomes necessary. It is at the same time desirable, however, that the timing mechanisms remain small and compact. To this end, ways and means are continually being sought to keep the camstack as small as possible.
In U.S. Pat. No. 3,142,730 there is described and claimed a stepped cam wherein the steps decrease in diameter in going from the bottom of the camstack to the top. This arrangement aided in reducing the size of the camstack. The camstack of the present invention also aids in reducing the size of the camstack and in addition makes it easier to use individual switches carries by a single common support. This aids in reducing the size of a complete cam switch assmebly and in addition, aids in reducing manufacturing costs.
In accordance with the invention there is provided a camstack which, in general, comprises a hub having an outer surface traced by a moving straight line passing through a fixed vertex and a plurality of ribs extending from the outer surface, each of the ribs having a cam surface substantially parallel to the first outer surface. In other words, the invention provides in a conical camstack of the type having a hub rotatable about a central axis, the improvement comprising a means for opening and closing a plurality of switches in a direction at an angle to the central axis and to the lines normal to the central axis. Framed in terms of the geometry of the camstack, the invention provides a camstack comprising: a first cam surface aligned along a first cone formed about a central axis of revolution of the camstack, wherein a projection of a locus of points from the first cam surface forms a first included angle with the central axis of revolution at a first vertex; at least one other cam surface aligned along a second cone formed about the central axis of revolution, wherein a projection of a locus of points from the one other cam surface forms a second included angle with the central axis of revolution at a second vertex; portions of the first cam surface and portions of the one other cam surface cooperating to provide cam lobe means for opening and closing a switch means in a direction at an angle to the central axis and to the line normal to the central axis. Preferably the projection of the first cam surface and the projection of the one other cam surface are equidistant between each other along these lengths. Preferably, the invention also provides a switch means engaging the cam surfaces. The invention further provides a timer comprising: a camstack rotatable about an axis of rotation; means for rotating the camstack about the axis; electrical switch means; and cam means on the camstack for opening and closing the electrical switch means in a direction at an angle to the axis and the lines normal to the axis. Preferably the camstack includes a plurality of cam surfaces and a projection of points along one cam surface intersecting the axis is parallel to a projection of points along the other cam surface(s) intersecting the axis.
The camstack according to the invention not only provides a more compact camstack assembly, but can be manufactured more reliably and accurately than prior art camstacks. Numerous other features, objects and advantages of the invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.
US Referenced Citations (2)
| Number |
Name |
Date |
Kind |
|
3142730 |
Slonneger et al. |
Jul 1964 |
|
|
3657493 |
Horsley |
Apr 1972 |
|
Foreign Referenced Citations (1)
| Number |
Date |
Country |
| 1196755 |
Jul 1965 |
DEX |
Continuation in Parts (2)
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Number |
Date |
Country |
| Parent |
48497 |
May 1987 |
|
| Parent |
932606 |
Nov 1986 |
|
Patent Grant
4814556
