|Title of Invention
CLAMP METER WITH TRIGGER MECHANISM
|This invention provides a clamp meter with safe trigger mechanism which allows an operator to take electrical measurements of the conductors safely, particularly in case of the electrical conductor elements situated in congested or awkward locations and positions, in the preferred embodiment of the present invention, the trigger is placed at the underside of said clamp meter so as to allow convenient access to it for the fingers of a hand while the clamp meter is held in the hand. The trigger mechanism of the invention may be operated with single or multiple fingers. The invention also allows the hand to maintain its ‘clinched-fist’ position throughout the measurement process, thereby eliminating the need to open the hand any time during the process. The invention thus makes the electrical parameter measurement operation using clamp meters safer than for the conventional meters.
THE PATENTS ACT 1970
(39 of 1970)
The Patent Rules, 2003
(See section 10 and rule 13)
Clamp meter with safe trigger mechanism
Rishabh Instruments Pvt. Ltd
Indian company registered under the Indian Companies Act, 1956.
F:31, MIDC, Satpur, Nashik 422 007, Maharashtra State, India
The following specification describes the invention:
CLAMP METER WITH SAFE TRIGGER MECHANISM
Field of the invention
This invention relates generally to electrical and electronic test and measuring instruments for measuring electrical current and particularly relates to multi meters that include clamp meters for the electrical current measurement.
Background of the invention:
Multimeters are used to measure a variety of electrical parameters such as AC voltage, AC current, DC voltage, DC current, and resistance. Clamp meters are a type of multimeters with a current sensing clamp.
Clamp meters are designed to measure current without breaking the current path and typically have two clamp jaws which open and close at a fixed position with respect to the body and display of the clamp meter. Current is measured by opening the jaws to close them around the conductor element carrying the current. The clamps are provided with electrical coils inside them. In the closed position of the clamp jaws, the current flowing in the conductor element (such as a busbar or a cable), of an electrical circuit creates a magnetic field in the coils. The current is measured by measuring the magnetic field. For measuring the electrical current, there does not need to be a electrical contact between the conductor element and the clamps.
The conventional clamp meters have a rectangular housing designed to be held in one hand. A pair of clamp jaws extends from one end of the housing. A trigger is provided to operate the opening and closing of the clamps in order to access the conductor whose measurement is to be taken. In conventional clamp meters, the clamp jaws can be opened and closed with a thumb operated lever which is
present just below one of the two clamp jaws that are present in these clamp
meters. The opening of clamp jaws may require substantial force. This can cause fatigue to the hand of the operator as all the force required to open the clamp jaws for enclosing the conductor is sustained by the thumb.
A drawback of the existing clamp meters is they are awakward to use in many circumstances. For example, there are many situations where the conductor elements that need monitoring are tightly and awkwardly placed in congested physical configurations, or placed overheads thereby making it awkward to work with them. Under these circumstances, when the clamp jaws are placed around conductor, the display and the keys might be orientated into a position which makes reading the display and operation of keys very difficult if not impossible.
The operator of the clamp meter tries, under such circumstances, either to take a reading by putting at risk their personal safety or they may not take any measurements at all on the grounds of lack of safe access to the conductor element.
As a further drawback of the existing clamp meters, as the thumb operated lever is very close to the clamps, user is exposed to dangerous high voltage when measuring the current in the live and often bare conductor element. When accessing conductors situated in congested or awkward locations, there is also a possibility that the clamp may slip accidentally and user may touch the live conductor and get electrocuted leading to serious injuries or fatality. This poses a definite risk to the property which houses the electric panels that contain such electric conductor elements.
There is therefore a need to provide a mechanism by which it will be possible for the operator to operate a clamp meter with the use of lesser hand movement than required by the existing clamp meters, thereby enabling them to operate the clamp meter with greater safety than in case of the existing clamp meters. There is also a
need to provide a clamp meter that can be operated with lesser force than required for the existing clamp meters, thereby reducing the fatigue that the operator experiences under such working conditions.
Clamp meter with safe trigger mechanism invention relates to measurement of current in the live bare conductor with trigger mechanism at the bottom side and away from the clamps to reduce the possibility of electric shock and operation of the trigger with more than one finger for reducing the fatigue to the operator.
Objects & Advantages of the invention
The primary object of the present invention is a to provide Clamp meter with safe trigger mechanism for taking current measurements with great amount of safety and low fatigue to the user.
One advantage of the present invention is that this invention, the clamp jaws can be opened or closed with the trigger at the bottom side which is safe location far away from the Live conductors. The danger of exposing the Human beings to electric shocks is minimized due to such construction.
Another advantage of the present invention is that as the trigger mechanism is at the bottom side, it can be opened or closed with more than one finger. The operation of trigger becomes easy as the force required to open the clamp jaws is taken by the fingers. This greatly reduces the user fatigue.
Brief Description of Drawings
FIG. 1 is a perspective view showing one embodiment of a Clamp meter with safe trigger mechanism of the present invention with clamps closed and trigger at normal position.
FIG. 2 is a rear view showing one embodiment of a Clamp meter with safe trigger mechanism of the present invention with clamps opened and trigger pressed.
FIG. 3 is a rear view showing one embodiment of a Clamp meter with safe trigger mechanism of the present invention with clamps opened, clamps rotated at an angle (Clock wise) and trigger pressed
FIG. 4 is a cut view showing trigger mechanism.
FIG. 5 is a partial view showing at an angle.
FIG. 6 is an exploded view of rotary Clamp mechanism
Summary of the invention:
This invention provides a clamp meter with safe trigger mechanism which allows an operator to take electrical measurements of the conductors safely, particularly in case of the electrical conductor elements situated in congested or awkward locations and positions. The trigger is placed at the underside of main body of the clamp meter so as to allow convenient access to it for the fingers of a hand while the clamp meter is held in the hand. The trigger mechanism of the invention may be operated with single or multiple fingers. The invention also allows the hand to maintain its 'clinched-fist' position throughout the measurement process, thereby eliminating the need to open the hand any time during the process. The invention
thus makes the electrical parameter measurement operation using clamp meters safer.
List of parts:
Pivot sleeve (10) Pivot screw (11) Pin (12) Trigger (13) Pusher(14) Hinge screw (15) Hinge C-clip (16)
Main body (1) Cover Housing (2) Base housing (3) Display screen (4) Function selection switch (5) Set of push buttons (6) Two input terminals (7) Clamp housing (8) Clamp jaws (9)
Detailed description of the invention:
The present invention provides a safe trigger for operating the clamps of a clamp meter. The trigger mechanism may be used in the current non-rotary type clamp meters, where the clamp jaws do not rotate out of their own plane. The trigger mechanism of the present invention may also be used in the rotary type clamp meters where the clamp jaws are able to rotate out of their own plane.
Referring to Figure 1, the main body of the clamp meter of the present invention is made of cover housing and a base housing, the two housings enclosing the measurement circuitry and some of the other parts of the clamp meter. A display screen, a function selection switch, and a set of push buttons to select testing parameters are housed within the housings and electrically connected to the measurement circuitry. Two input terminals are also provided for connecting the test leads.
A clamp housing houses clamp jaws. Clamp jaws are connected to the clamp housing through an arrangement comprising a pivot sleeve and pivot screw for each of the clamps. The two jaws are connected to each other through a central hinge arrangement wherein each of the jaws have a loop that are positioned axially, through which a pin passes to form the hinge arrangement.
A trigger is used to operate the clamp jaws into their open and close positions. The trigger is hinge connected to the main body of the clamp meter by connecting it with a hinge to the base housing. A hinge screw and a hinge C-clip is used for this purpose. The protruding end of the trigger is used by the operator to activate the trigger. The hinge end of the trigger is in contact with the ball end of a pusher . The other end of the pusher is connected to the clamp jaws with the help of a metal pin that operates the clamp jaws.
When pressed, the trigger pushes the spherical end of a pusher. The pin is fixedly attached to the other end of the pusher. When the trigger is pressed, the pusher gets pushed along its axis, thereby moving the pin in the same direction. The pin, through the central hinge arrangement, makes the clamp jaws rotate in their own plane, thereby opening them. In their open position, the clamp jaws press against the compression springs. Upon the release of the trigger, the compression springs push the clamp jaws back into their closed position.
Although the invention has been described with reference to certain preferred embodiments, the invention is not meant to be limited to those preferred embodiments. Alterations to the preferred embodiments described are possible without departing from the spirit of the invention. However, the apparatus described above is intended to be illustrative only, and the novel characteristics of the invention may be incorporated in other structural forms without departing from the scope of the invention.
Dated This 18th Day of May, 2007
Mr. Vijay Sharatchandra Tase Patent agent for the applicant Registration number: IN/PA 987
The Controller of Patents
The Patent Office, Mumbai Branch
Antop Hill, Mumbai
|Indian Patent Application Number
|PG Journal Number
|Date of Filing
|Name of Patentee
|RISHABH INSTRUMENTS PVT LTD.
|F:31, MIDC, SATPUR, NASHIK
|PCT International Classification Number
|PCT International Application Number
|PCT International Filing date