The present invention relates to an electrical connecting device with a spring connecting element, in particular an electrical connecting terminal for the connection of one or more electrical conductors, equipped with a compact actuator. In particular, without excluding other embodiments of the invention, the electrical connecting element is in the form of an electric contact element, either male (plug) or female (socket).
In particular, the electrical connecting device in question may also be suitable to be housed in the insulating body of a multipole connecting device, such as an electrical connector, for connecting an electrical conductor either of a type with a plurality of strands (flexible conductor) or of the single-wire type (rigid or flexible but prepared with a crimped ferrule termination).
Elements of electrical connection and electrical connection terminals suitable for connecting one or more electrical conductors through the action of a tension spring are known.
Among the most common forms of tension spring for said elements there is one described in DE 2706482 (Wago), in particular made from a strip of resilient material shaped in the manner of a ring.
In DE 102007009082 (ILME) an evolution of such connecting devices with spring contacts is described which provides for the presence, for each terminal, of an actuator in the form of a sliding pin that operates the closing or opening of the tension spring and consequently the connection or the release of the conductor to/from the terminal without the use of a tool (e.g. with a screwdriver with slot shaped tip) for closing the connection terminal for the realization of the electrical connection between the conductor and the contact, making said tool necessary only for any subsequent reopening. This invention has rendered the wiring operation independent of the operator, i.e. from the level of training and expertise of the operator.
In IT MI2012A00001974 (ILME), not yet published, a further evolution of the invention previously invoked is described, in which the actuators of the spring connecting elements are provided with a longitudinal groove adapted to allow, for example, the introduction of a metal probe to perform electrical measurements.
The electrical connecting devices with spring contacts and actuator of the prior art, based on the typical ring shape of the spring referred to in the aforementioned DE 2706482, suffer the inconvenience of determining a rather remarkable transverse dimension: the actuator pin, frontwards shaped with a cam profile, so as to operate the opening and closing of the spring terminal by acting on the so-called “leg” of the spring, has by necessity, upon connecting element in the “open” position, a transverse dimension, rearwards of the spring itself, which yields to a limitation of the density of the spring connecting elements with actuator, implementable on adjacent parallel rows, for example in multipole compact terminal blocks or in multipole electrical connectors.
For the relevant slots in the insulating body of the multipole terminal block or of the multipole connector, consistent transverse dimensions are hence required, such as to prevent the adoption of such electrical spring connecting elements with actuator in multipole devices with a high contact density, in particular when e.g. the multipole connector insert is limited in its maximum size by the useful internal size of the respective protective housing.
An alternative embodiment of the actuator pin in the prior art devoid of transverse dimensions posteriorly to the spring, while not varying the shape of the latter with respect to the classic one of the prior art, provides a greater overall width of the actuator pin itself, which embraces the spring to the sides, but for a connecting device equipped with such an electrical spring-type connecting element with actuator, it involves a greater width dimension due to the necessarily increased lateral dimension of the actuator pin. This makes it inconvenient to use such a connecting element in preexisting multipole connecting devices, for the increase of pitch that would be required between such connecting elements arranged side by side.
An alternative of spring-type connecting element with actuator based on a different spring design, with a spring element with a sleeve shape, is described in DE 10145324 (EP 1294053) (Harting). This technique, although more compact, suffers however from serious drawbacks: (1) it is still necessary a tool (e.g. screwdriver with slot shaped tip) for the closure of the terminal, because of the small size of the actuator pin and (2) it is only suitable for stranded flexible conductors, thus not for conductors prepared with insulated crimp ferrule (a solution much appreciated by the manufacturers of wiring harness for electric panels) or single-pole conductors, either solid or stranded, the use of which is still widely diffused in many countries for the wiring of fixed electrical installations.
The purpose of the present invention is therefore to eliminate the drawbacks of the above described prior art, in particular to provide an electrical connecting device with a spring-type connecting element as described in DE 2706482, provided with actuator as foreseen in DE 102007009082, which has a compact shape, so as to reduce the transverse dimensions of the device, and to increase the density of the connecting elements in case of use of the same in multipole connectors, while keeping all the advantages offered by the spring-type connecting element with a ring-shaped spring. Another purpose of the invention is to provide such an electrical connecting device suitable for both flexible and rigid conductors and suitable to accommodate even more than one conductor.
Further object of the invention is to provide such an electrical connecting device which is simple and economical to produce.
The electrical connecting device according to the invention has the characteristics of independent claim 1.
Advantageous embodiments of the invention are set forth in the dependent claims. Basically, the electrical connecting device according to the invention, comprising a body that houses the spring-type connecting element and the actuator, presents a reshaping of the tension spring of the connecting element, in particular in a limited portion of the so-called “leg” of the ring-shaped spring (also known as cage), which acts as a lever arm for the closure of the portion which operates as the veritable spring, constituted by a lower portion curved in a semicircle.
The portion of the above mentioned “leg” is suitably symmetrically tapered on the sides and the corresponding profile of the actuator pin is specularly hollowed in such a way to completely wrap the aforementioned tapered rear portion of the tension spring, when the spring-type connecting element is in fully closed terminal position (and the cage spring is at its maximum extension).
Thus, compared to the known technique, the overall transverse dimensions of the actuator pin becomes usefully reduced down to zero in the closed terminal position (the position of maximum transverse dimension).
It is therefore made possible to house an electrical spring-type connecting element with actuator such as this e.g. in compact multipole terminal blocks or in high density multipole connectors which foresee more rows of adjacent and close together contacts. In particular, for use in multipole connectors, one obtains maintaining the maximum transverse footprint of the spring-type connecting element with actuator equal to that required in similar multipole connectors with spring-type connecting devices without actuator. Hence, the same mating interface (thus the same contact density) of the existing multipole spring-type connectors without actuator can be kept in the spring-type versions with actuator.
Further characteristics of the invention will appear more clearly from the detailed description that follows, referring to a merely exemplary, and therefore non-limiting, embodiment, illustrated in the enclosed drawings, in which:
a), b), are similar to those of
In
The connecting element 30 has a terminal 31 with ring-shaped tension spring (also known as cage) 32 and, in the example reported, a pin-shaped male electric contact element 33 downwardly protruding from the insulating body 20. Alternatively, the electric contact element 33 may be of the socket female type.
The tension spring 32, known per se, as described in DE 2706482, is a leaf spring that has just a closed ring conformation, with a curved lower portion, substantially in a semicircle 34 which acts as the veritable spring, a back ascending portion that will be called “leg” 35 and an upper portion 36 with a slot 37 housing in an upper protrusion 38 of the connecting element 30 or of a portion of spring opposite to the leg 35, to allow the flexing of the spring as a result of an external stress, and therefore the opening and closing of the terminal.
The actuator pin 40 is of prismatic shape with vertical longitudinal development and can slide in the respective seat 24 to actuate the spring 32 and open or close the terminal. In particular, the actuator pin 40 has at the bottom a front profile of the cam type with a projecting portion 41 adapted to interfere with the said spring 32 to operate the opening and closing of the terminal, and a depression 42 adapted to house said leg 35 of the spring 32 in the closed terminal condition and in absence of the conductor.
The actuator pin 40 also presents an upper side seat 43 for a manual tool such as a screwdriver with slot shaped tip 50 (see particularly
The actuator pin 40 also presents a longitudinal aperture 44 facing in the direction of the spring 32, adapted to allow the insertion of the probe of a testing device for making electrical measurements, as described in the aforesaid not yet published IT MI2012A001974 patent application.
The substantial differences of the connecting device according to the present invention compared to the one described in the document DE 102007009082, which allow to reduce the device's internal transverse dimensions, and thus to obtain an increase of the density of connecting elements in case of multipole terminal blocks or connectors, consist in the fact that the aforementioned depression 42 formed in the actuator pin 40 is a recessed seat in the thickness of the pin, delimited by two opposite vertical walls 45 (best seen in
With reference to
By leveraging on the suitably relieved upper edge of the cover 22 of the body 20 a downward rotation of the screwdriver 50 is operated causing the lifting up of the actuator pin 40, whose protruding portion 41 of the cam profile operates the compression of the spring 32 with the corresponding opening of the connection and the release of the conductor 60 which can be extracted, as shown in
In particular, in the example shown in
From the foregoing, the advantages of the invention appear evident, which is not however limited to the particular embodiment previously described and illustrated in the appended drawings, but which can be subject to numerous modifications of detail within reach of the technician skilled in the art, without departing from the scope of the invention defined by the appended claims.
Number | Date | Country | Kind |
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M12013A0200 | Feb 2013 | IT | national |
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Number | Date | Country |
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27 06 482 | Aug 1978 | DE |
10145324 | Apr 2003 | DE |
102007009082 | Sep 2007 | DE |
1294053 | Feb 2014 | EP |
06-215810 | Aug 1994 | JP |
Entry |
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European Search Report dated Oct. 2, 2013; IO 37508 IT M20130200. |
Number | Date | Country | |
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20140227914 A1 | Aug 2014 | US |