FORM -2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
ACTUATORS
Thermax Limited,
an Indian Company of
D-13, MIDC Industrial Area, R.D.Aga Road, Chinchwad, Pune- 411019 Maharashtra, India.
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE INVENTION
The present invention relates to the field of actuators.
In particular, this invention relates to electromechanical actuators.
BACKGROUND
An actuator is a mechanical device for moving or controlling a mechanism or system. Specifically, an electromechanical actuator is used to provide reversible linear motion at a controlled speed. The rotary motion of a motor is converted to linear displacement of the actuator. This can provide a pushing or pulling force of a considerable magnitude. Suitable leverage can enhance its utility in various applications. An electromechanical actuator has several advantages including having identical extending or retracting behaviour, possibility of a position feedback and automated operation. When considering an actuator for a particular application, the most important specifications are typically travel, speed, force, accuracy, available space and lifetime. Electromechanical actuators find application wherein it is required to tilt / pivot, lift / lower, roll / slide, open / close, tension adjustment, periodic position adjustment and the like.
Electromechanical actuators known in the art, especially for tilt applications, typically, in movement mechanisms for focusing parabolic solar dish reflections on a receiver are plagued by challenges including:
• huge manpower requirement;
• cumbersome seasonal adjustments;
• longer time for adjustments;

• tracking accuracy dependent on the skill of the people operating the mechanism; and
• need for infrastructure such as platforms / ladders;
There is therefore felt a need for actuators that address these shortcomings associated with the prior art.
OBJECTS OF THE INVENTION
One object of the invention is to provide an actuator that is not labor intensive.
Another object of the invention is to provide an actuator that can be applied to parabolic solar dish reflectors.
Still another object of the invention is to provide an actuator that can be used for second axis movement control of parabolic solar dish reflectors.
Yet another object of the invention is to provide an actuator whose operational accuracy is independent of the skill of the people operating the actuator.
One more object of the invention is to provide an actuator that does not require cumbersome seasonal adjustments.
Another object of the present invention is to provide an actuator that effects positional changes in a relatively short time.

Still another object of the invention is to provide an actuator that obviates the need for infrastructures such as platforms / ladders.
One more object of the invention is to provide an actuator that is compact.
Still one more object of the invention is to provide an actuator that is cost effective.
Yet another object of the invention is to provide an actuator with automated controls.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an actuator for a mechanism, the actuator comprising:
> a coupler adapted to connect the actuator to the mechanism;
> a telescopic threaded shaft assembly comprising at least one upper shaft with external threads, one intermediate shaft with internal and external threads and one lower shaft with internal threads to lock the shaft assembly in an operative configuration;
> a drive assembly adapted to co-operate with the telescopic threaded shaft assembly to drive the actuator; and
> triggering means adapted to trigger operation of the drive assembly.
Preferably, in accordance with this invention, the drive assembly is an electromechanical assembly comprising a geared motor and a spur pinion gear.

Typically, in accordance with the present invention, the operative configuration is at least one of an extended configuration, a retracted configuration and a partially retracted configuration.
Typically, in accordance with the present invention, the threads are provided with a pre-determined pitch to provide micro movement of the upper shaft and the intermediate shaft.
Preferably, in accordance with the present invention, the external threads of the upper shaft are adapted to self lock with the internal threads of the intermediate shaft, the external threads of the intermediate shaft are adapted to self lock with the internal threads of the lower shaft.
Preferably, in accordance with the present invention, the triggering means co-operates with a feedback system, typically an image processing means.
Additionally, in accordance with the present invention, the triggering means is a pre-calculated time bound input power controlled by a Programmable Logic Controller (PLC) co-operating with a feedback system.
Optionally, the triggering means is a manual push button.
In accordance with the present invention, a dual axis solar tracking reflector utilizes the actuator as described herein above for precise movement of the second axis in a linear direction.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The invention will now be described with the help of accompanying drawings, in which:
FIGURE 1 illustrates a cross sectional representation of an actuator in accordance with the present invention;
FIGURE 2 illustrates details of the gear box and motor assembly designated as part'X'in FIGURE 1;
FIGURE 3 illustrates a cross sectional representation of a side view of the actuator illustrated in FIGURE 1;
FIGURE 4 illustrates details of the gear box and motor assembly designated as part 'Y' in FIGURE 3; and
FIGURE 5 illustrates a retracted configuration of the actuator of FIGURE 1.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The invention will now be described with reference to the embodiments shown in the accompanying drawings. The embodiments do not limit the scope and ambit of the invention. The description relates purely to the exemplary preferred embodiments of the invention and its suggested applications.
The present invention envisages an actuator that addresses the need for accurate position adjustment of the second axis in a dual axis tracker for

focussing parabolic solar dish reflections on a receiver, such an actuator being compact, easy to operate and cost effective.
The actuator in accordance with the present invention will now be explained with reference to FIGURES 1, 2, 3, 4 and 5, wherein FIGURE 1 illustrates a cross sectional representation of an actuator in accordance with the present invention; FIGURE 2 illustrates details of the gear box and motor assembly designated as part 'X' in FIGURE 1; FIGURE 3 illustrates a cross sectional representation of a side view of the actuator illustrated in FIGURE 1; FIGURE 4 illustrates details of the gear box and motor assembly designated as part 'Y' in FIGURE 3; and FIGURE 5 illustrates a retracted configuration of the actuator of FIGURE 1.
The main components of the actuator in accordance with the present
invention as illustrated in the aforementioned figures are generally
referenced as given below:
coupler 10;
upper shaft 12;
intermediate shaft 14;
lower shaft 16;
oil seal 18;
geared motor 20; and
motor shaft 22;
spacer 24;
shaft 26;
washer / socket head / cap screw 28;
spur / pinion gear 30;

hex. bolt with plain washer 32;
spacer 34;
hex bolt 36;
spacer / locking washer / lock nut 38;
socket head cap screw with plain washer 40;
box 42; and
bearing housing 44.
Although the actuator in accordance with the present invention is described herein below with reference to its application to a solar tracking system, the application of the device is not limited to solar tracking. The actuator can be utilized for other tracking applications such as spying devices, CCTV cameras, cameras at traffic signals and the like requiring tracking of a moving object.
The geared motor 22 and the spur / pinion gear 30 are selected based on the application and suitability. The upper shaft 12, the intermediate shaft 14, and the lower shaft 16 are provided with a telescopic arrangement with a plurality of configurations namely, an extended configuration, a retracted configuration, and a partially retracted configuration.
The upper shaft 12 and the intermediate shaft 14 are extended from the lower shaft 16 in the extended configuration whereas the upper shaft 12 and the intermediate shaft 14 are collapsed inside the lower shaft 16 in the
retracted configuration.
The telescopic arrangement as described herein above enables push or pull of the axis of the solar dish reflector which self lock once set and is of a

reciprocating nature. The size of the telescopic arrangement is such that it makes the actuator in accordance with the present invention compact. The actuator in accordance with the present invention is suitable for outdoor installation and because of the compact size, it can be utilized where space is a concern.
Image processing means is utilized for providing a feedback to the electromechanical mechanism of the actuator to maintain focus at the center of the receiver of the solar concentrator. The image processing means also facilitates the flexing of the solar reflector by changing its shape to a desired shape.
The actuator in accordance with the present invention can be utilized for micro movement of any object depending on the capacity of the geared motor 22 that provides a drive for the actuator. The precise movement is achieved through at least one of a time bound input power triggered by a manual push button or a pre-calculated time bound input power controlled by a Programmable Logic Controller (PLC) in conjunction with a feedback system utilizing image processing means.
The device in accordance with one aspect of the present invention provides accurate automated mechanised micro movements of the second axis of parabolic solar dish reflectors in a linear direction through an electromechanical mechanism of size 700mm to 2200mm operated manually by an electrical push button or though a Programmable Logic Controller (PLC) for a solar concentrator of size 7m to 100m .

In accordance with one another aspect of the present invention, the operation of the actuator is automated to control the movement of the second axis of a solar dish reflector based on the solar calendar.
In accordance with yet another aspect of the present invention, a linear scale is provided to measure linear movement.
In accordance with one more aspect of the present invention, the automated movement control is achieved using different types of drives.
TECHNICAL ADVANCEMENTS AND ECONOMICAL
SIGNIFICANCE
The technical advancements offered by the present invention which add to the economic significance of the invention include the realization of:
• an actuator that is not labor intensive;
• an actuator that can be applied to parabolic solar dish reflectors;
• an actuator that can be used for second axis movement control of parabolic solar dish reflectors;
• an actuator whose operational accuracy is independent of the skill of the people operating the actuator;
• an actuator that does not require cumbersome seasonal adjustments;
• an actuator that effects positional changes in a relatively short time;

• an actuator that obviates the need for infrastructures such as platforms / ladders;
• an actuator that is compact;
• an actuator that is cost effective; and
• an actuator with automated controls.
The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
Wherever a range of values is specified, a value up to 10% below and above the lowest and highest numerical value respectively, of the specified range, is included in the scope of the invention.
While considerable emphasis has been placed herein on the particular features of this invention, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiment without departing from the principles of the invention. These and other modifications in the nature of the invention or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We Claim:
1. An actuator for a mechanism, said actuator comprising:
> a coupler adapted to connect said actuator to the mechanism;
> a telescopic threaded shaft assembly comprising at least one upper shaft with external threads, one intermediate shaft with internal and external threads and one lower shaft with internal threads to lock said shaft assembly in an operative configuration;
> a drive assembly adapted to co-operate with said telescopic
threaded shaft assembly to drive said actuator; and
> triggering means adapted to trigger operation of said drive assembly.
2. The actuator as claimed in claim 1, wherein the drive assembly is an electromechanical assembly comprising a geared motor and a spur pinion gear.
3. The actuator as claimed in claim 1, wherein said operative configuration is at least one of an extended configuration, a retracted configuration and a partially retracted configuration.
4. The actuator as claimed in claim 1, wherein the threads are provided with a pre-determined pitch to provide micro movement of said upper shaft and said intermediate shaft.
5. The actuator as claimed in claim 1, wherein the external threads of said upper shaft are adapted to self lock with the internal threads of

said intermediate shaft, the external threads of said intermediate shaft are adapted to self lock with the internal threads of said lower shaft.
6. The actuator as claimed in claim 1, wherein said triggering means is a manual push button.
7. The actuator as claimed in claim 1, wherein said triggering means co-operates with a feedback system.
8. The actuator as claimed in claim 7, wherein said feedback system is an image processing means.
9. The actuator as claimed in claim 1, wherein said triggering means is a pre-calculated time bound input power controlled by a Programmable Logic Controller (PLC) co-operating with a feedback system.
10. A dual axis solar tracking reflector utilizing the actuator of claim 1 for precise movement of the second axis in a linear direction.