Clamp meter with rotary mechanism for clamp jaws

[0001] The present invention relates generally to electric and electronic testing and measuring instruments for measuring electric current, and in particular relates to multimeters comprising clamps for measuring electric current.

Background Art [0002] Multimeters are used to measure various electrical parameters, such as alternating voltage, alternating current, direct voltage, direct current, and resistance. Clamp meters are a type of multimeters equipped with clamps that detect electric current.

[0003] Clamp meters are designed to measure current without interrupting the current path and usually have two clamp jaws that open and close in a fixed position relative to the body and display of the clamp meter. Current is measured by opening the jaws and closing them around the conductive element. The clamps contain electric coils inside. In the closed position of the clamp jaws, the current flowing through a conductive element (such as a rail or wire) of the electric circuit induces a current in the coils that is proportional to the current flowing through the conductive element. There must be no electrical contact between the wire and clamp for measuring the electric current.

[0004] Conventional clamp meters have a rectangular housing designed to be held in one hand. A pair of clamp jaws protrudes from one end of the housing. The jaws are in a fixed plane that is substantially parallel to the plane of the front of the housing. The meter display is usually located in the front of the housing, as shown in US Patent Nos. 6,975,104 and US6456060.

[0005] A disadvantage of existing clamp meters is their inconvenient use in many situations where conductive elements requiring monitoring are placed in densely packed installations. In these cases, when the clamp jaws are closed around the guide, the display and buttons may be in a position that makes display reading and key operation extremely difficult or impossible. This makes measuring and monitoring the process cumbersome. Conductors that are either overhead or placed in tight spaces such as electrical cabinets are examples of this.

[0006] The clamp meter operator may in such conditions try to read the result risking his own safety or give up the measurement due to the lack of safe access to the measured element.

[0006] Accordingly, there is a need for an improved clamp meter in which the clamp jaws can be easily adapted so that the operation of the clamp meter and display readings become easy.

[0007] US 4,283 677 discloses a clamp galvanometer.

Objects and advantages of the invention [0008] Accordingly, one of the objects of the present invention is a clamp meter having rotatable clamps that can be rotated at different angles to allow access to conductive elements such as rails, wires or other conductors that are arranged in physically uncomfortable or relatively inaccessible places for measuring current.

[0009] Another object of the present invention is a clamp meter that can be rotated to facilitate the measurement of current in conductive elements such as rails, wires or other conductors placed in physically uncomfortable or relatively inaccessible places, visualizing the display of the clamp meter by turning the clamp jaws.

[0010] Still another object of the present invention is a clamp meter whose buttons and function selector switch are easy to operate in the field.

[0011] Another object of the present invention is the clamp meter, which is divided so that the measuring part is separated from the control part.

Brief description of the drawings [0012]

Fig. 1 is an axonometric view from above which shows a clamp meter with a rotary clamp mechanism according to the invention in a normal position.

Fig. 2 is an axonometric bottom view showing a clamp meter with a rotary clamp mechanism according to the invention in a normal position.

Fig. 3 shows the clamp meter with the clamps in a rotated position.

Fig. 4 shows the clamp mechanism in the measurement configuration with the clamps in a rotated position.

Fig. 5 shows the opening and turning mechanisms of the clamp jaws.

Fig. 6 shows several views of the rotary mechanism.

Fig. 7 is an exploded view of rotary and opening mechanisms.

Fig. 8 shows a gear with a ratchet of a rotating mechanism for locking the position of the clamp jaws at a different angle.

Figures 9 and 10 show different variants of the ball end of the pusher.

Figures 11 and 12 show the arrangement of the separate products of the present invention.

Summary of the invention:

[0013] The subject of the invention is a clamp meter as defined in claim 1. Preferably, the position of the clamping jaws is adjustable in different planes for different predetermined angles to assist the user in measuring current in conductors that are arranged in tight physical spaces such as electrical cabinets or electrical panels or are placed in an unusual position, such as overhead locations. The present invention allows the user to operate the device and read the display in all clamp positions.

List of parts:

[0014]

Body (1)

Housing cover (2)

Housing base (3)

Display screen (4)

Function selector switch (5)

Button set (6)

Two input terminals (7)

Clamps cover (8)

Clamps (9)

Rotating sleeve (10)

Rotating screw (11)

Peg (12)

Trigger (13)

Pusher (14)

Ball end of the pusher (14a)

Compression Springs (15)

Shield (16)

Appearances (17)

Grooves (18)

Locking springs (19)

Ball (20)

Eye (21)

Variant of the spherical end (14b)

Detailed description of the invention [0015] Fig. 1 shows the clamp meter according to the invention with the clamps in a normal position.

[0016] The current measurement process with a typical clamp meter is given below:

a. Selection of the measurement function, such as AC voltage, DC voltage, resistance, diode, AC voltage, by means of a rotary function selector switch;

b. Access to the guide;

c. Setting the clamp jaws position around the conductor;

d. Using the buttons: turn ON and OFF the digital clamp meter to select optional additional functions, such as automatic range selection, manual range setting, minimum reading, maximum reading, latching data hold function; and selection of alternative functions such as frequency, circuit continuity;

e. Reading on the display.

[0017] The clamp meter of the present invention allows to perform all these functions, as shown in Fig. 3. One of the main features of the present invention is that some or all of the above operations can be performed in any rotated position of the clamp.

[0018] Referring to Figs. 1 and 2, the body (1) of the clamp meter according to the present invention has a housing cover (2) and a housing base (3) that surround the measuring circuit of the clamp meter. The display screen (4), the function selection switch (5) and a set of buttons (6) for parameter selection are located in two parts of the housing and are electrically connected to the measuring circuit. The two input terminals (7) are intended for connecting test leads.

[0019] The clamp protector (8) includes the clamp jaws (9). The clamp jaws (9) are connected to the clamp cover (8) by a system comprising for each clamp a rotary sleeve (10) and a rotary screw (11). The two jaws (9) are connected to each other by means of a central articulated system, in which each jaw has an eye (21), and the eyes of both jaws (9) are arranged axially. A dowel (12) located in the mesh openings made of metal or other suitable material such as hard plastic, hard rubber or wood forms a central articulated system.

[0020] Referring to Fig. 5, the trigger (13) is used to close and open the clamp jaws (9). When pushing, the articulated end of the trigger (13) pushes the spherical end (14a) from the articulated side, also known as the pusher trigger end (14). The pin (12) is permanently attached to the other end of the pusher (14). When the trigger (13) is pressed, the pusher (14) moves along its axis, thus moving the pin (12) in the same direction. The pin (12), through the central articulated system, opens the clamp jaws (9) by turning them in its plane. This is possible by rotating each jaw around its own sleeves (10), thereby opening them around the pin (12) as a pivot point. In the open position, the clamp jaws (9) press on the compression springs (15). After releasing the trigger (13), the compression springs (15) return the clamp jaws (9) back to their closed position, again by turning each clamp jaw around the pin (12) as a pivot point.

[0021] As shown in Figs. 9 and 10, the end of the pusher trigger (14) is pushed by the trigger (13). The articulated end of the trigger (13) may be of a non-spherical shape and of a non-solid type, and its shape may be selected from the group consisting of a wedge, multi-wedge or many other curvilinear shapes or combinations thereof, so that the trigger pushes the pusher effectively without slack.

[0022] The clamp jaws (9) contain electric coils which are electrically connected to the current measuring system in the conductor. The measurements are displayed on the display screen (4).

[0023] In conventional clamp meters, the clamp jaws (9) and the body (1) of the clamp meter are in the same plane constant. As shown in Fig. 3, one of the main features of the present invention is the rotary mechanism by which the clamp jaws (9) can rotate together in different planes relative to the plane of the clamp meter body (1), allowing the clamp meter operator to access densely packed measurement areas. The clamp jaws (9) together rotate about the longitudinal axis of the pusher (14). The innovative rotary mechanism allows the clamp jaws (9) to be turned in both the open and closed positions.

[0024] In an embodiment of the present invention, the clamp jaws (9) may be permanently located in a plane other than the plane of the clamp meter body (1); in this case it is an option to make the product of the present invention without the rotary mechanism.

[0025] The novel rotary mechanism is now described. Various parts of the rotary mechanism are shown in Figs. 6, 7, and 8. The disc is integrally formed with the clamp housing (8) as shown in Fig. 8. The rim of the disc is shaped so as to have alternately projections (17) and grooves ( 18) in the plane of the shield.

As shown in Fig. 8, in a preferred embodiment of the present invention, the two balls and the gripping system are on opposite sides of the disk. Each ball (20) cooperates with a locking spring (19) to ensure that the ball (20) is positioned in the groove when no rotational force is applied. Instead of locking springs (19), an elastic material such as rubber or special polymers can be used. After applying a rotational force to the clamp, the ball (20) in the gripper system will be pressed to the nearest projection and will slide along its profile. When the projection hump passes, it is pressed into the next groove, as a result of which the clamps remain in a rotated position relative to the body (1) of the clamp meter. Many rotation steps are possible, which corresponds to each wheel groove. For continuous rotation of the clamp jaws (9), the rotating force is applied continuously, the ball (20) traveling through the grooves (18) and the protrusions until the clamp cover (8) reaches the required position. At this moment the rotational force is stopped and the clamp jaws (9) are locked in the rotated position.

[0027] In an embodiment of the invention, the two balls and gripper systems may be located anywhere along the periphery of the disc, not necessarily on opposite sides.

[0028] In another embodiment of the present invention, the number of balls and gripper systems may be one or greater than two.

[0029] The size of the grooves and protrusions (17) is determined depending on the desired minimum angle by which the clamp jaws (9) are to be rotated. It is also possible to use a system that allows continuous rotation of the meter body (1). This may result from the use of a ball bearing mechanism so that the jaws of the clamps (9) can be effectively locked at any angle to the body (1). [0030] The shape of the grooves (18) and protrusions may be round, elliptical or any other such that does not impede the movement of the ball (20) along the edge of the disc.

[0031] As can be seen from the above discussion and as shown by the arrows the movement in Fig. 3, the novel rotary mechanism disclosed in the present invention ensures that the clamp protector (8) can freely rotate clockwise and counterclockwise relative to the body (1). ) clamp meter. It is therefore possible to keep the clamp cover (8) at various predetermined angles in order to gain access to conductors that are located in uncomfortable places or which are inaccessible to existing clamp meters. It is also obvious that all the functions of typical clamp meters are possible to perform with the rotary clamp meter according to the invention in any position of the clamp jaws (9).

[0032] The present invention also has another significant advantage. Electricians or other people who would ignore conductor measurements in hard to reach or inaccessible places can now take measurements in such uncomfortable places. This makes it possible to detect conductors in which a dangerous current flows or to make measurements in conditions where the safe values ​​of voltage, current, etc. are exceeded. This in turn is a great preventive step against any future threats leading to damage or loss of property as a result of electrical failures, fires caused by overheating of wires, etc.

[0033] In another embodiment of the present invention, the trigger (13) can be located anywhere, such as the side of a clamp meter, or any other place that allows the clamp jaws (9) to work properly and can be positioned asymmetrically relative to the center of the meter body (1) clamp.

[0034] In yet another embodiment of the present invention, the disk (16) can be made of electrically non-conductive hard or semi-hard material.

In yet another embodiment of the present invention, the disk (16) may not be an integral part of the clamp housing (8). The disc (16) can be made separately and can be permanently attached to the clamp guard (8) in any way, such as gluing, welding, welding, etc.

[0036] In yet another embodiment of the present invention, the rim profile of the disc (16) may be one that allows the ball (20) to easily move through the grooves (18) and protrusions while applying rotational force and blocks the ball (20) securely. ) in the grooves (18) when no rotational force is applied.

In yet another embodiment, as shown in Figs. 11 and 12, the trigger (13) and clamp jaws (9) can be enclosed together in a jaw assembly (or measuring assembly) which is separated from the control system comprising the display, a selection switch functions (5), parameter measuring instruments, etc. In this embodiment, the jaw assembly is connected wirelessly or physically to the measuring system. The jaw assembly includes jaws that are rotatable relative to the body (1) or are fixed at any angle.

[0038] In yet another embodiment of the present invention, the clamp jaws (9) may be locked in a specific position with respect to the plane of the clamp meter body (1).

[0039] In yet another embodiment of the present invention, the lever material, clamp jaws, cover, and housing base may be made of any material selected from the group consisting of metals, metal alloys, plastics, rubber or other suitable material or a combination of these materials .

[0040] Although the invention has been described with reference to certain embodiments, the invention is not limited to these embodiments. Changes to the described embodiments are possible without departing from the scope. However, the above description of the device is only intended to illustrate it, and the novel features of the present invention may be incorporated into other structures without departing from the scope of the invention.