Patent Publication Number: US-2023163544-A1

Title: Electric connection device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present Application is a national stage of International Patent Application No. PCT/IT2021/050097 titled “Electric Connection Device,” filed Apr. 9, 2021, which claims priority from Italian Patent Application No. 102020000008098 titled “Electrical Connection Device,” filed Apr. 17, 2020, the contents of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1) Field of the Invention 
     The present invention refers to an electrical connection device. 
     In particular, the invention refers to an electrical connection device of the rotating type, commonly known as a rotating joint or collector, for the electrical connection of two rotating elements. 
     2) Background Art 
     Rotating electrical connection devices used to transmit current between a fixed part and a mobile part of an equipment, for example of a machine, are known. 
     Such known electrical connection devices comprise a container inside which a sliding contact is inserted, formed by a fixed part and a movable part in contact with each other and each connected to respective electric cables. 
     These known electrical connection devices, however, are not satisfactory since they have the problem of having an excessive bulk, when it is necessary to connect a plurality of electrical cables. 
     Another problem of known electrical connection devices is that of ensuring good contact reliability over time, at reduced costs. 
     CN201122783Y discloses an electrical connection device according to the preamble of claim  1 . 
     SUMMARY OF THE INVENTION 
     Object of the present invention is providing an electrical connection device which has reduced overall dimensions, especially in the longitudinal direction, and which is reliable and inexpensive. 
     The aforementioned and other objects and advantages of the invention, which will emerge from the following description, are achieved with an electrical connection device such as the one described in the main claim. Preferred embodiments and non-trivial variants of the present invention form the subject of the dependent claims. 
     It is understood that the attached claims form an integral part of the present description. 
     It will be immediately obvious that innumerable variations and modifications (for example relating to shape, dimensions, arrangements and parts with equivalent functionality) can be made to what is described without departing from the scope of the invention as appears from the attached claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be better described by a preferred embodiment, provided by way of non-limiting example, with reference to the attached drawings, in which: 
         FIG.  1    shows an exploded view of an electrical connection device according to the present invention; 
         FIG.  2    shows an exploded view of a detail of an electrical connection device according to the present invention; 
         FIG.  3    shows a side sectional view of an electrical connection device according to the present invention; 
         FIG.  4    shows a top view of an electrical connection device according to the present invention; and 
         FIG.  5    shows an exploded view of a detail of an embodiment of an electrical connection device according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     With reference to  FIGS.  1 - 5   , the electrical connection device  10  of the present invention comprises a container  11  comprising at least two seats  12 , each seat  12  being configured to contain an electrical connection element  14  comprising a first sliding contact element  15  and a second sliding contact element  16 , each of the sliding contact elements  15 ,  16  being connectable to a respective electric cable (not shown in the figures). 
     The electrical connection device  10  also comprises a tubular element  21  inserted inside the container  11  so that the tubular element  21  and the container  11  are rotatable relative to each other, the tubular element  21  being shaped to allow the passage of at least one electric cable connected to the electric connection element  14 ; preferably the tubular element  21  comprises at least one longitudinal recess  45  for the passage of an electric cable. 
     The first sliding contact element  15  is integrally connected to the container  11  and the second sliding contact element  16  is integrally connected to the tubular element  21 , so as to rotate relative to each other to make a sliding contact between the sliding contact elements  15 ,  16 . 
     Preferably, each electrical connection element  14  further comprises an elastic element  17 , for example a leaf spring, configured to keep the first sliding contact element  15  and the second sliding contact element  16  in contact, for example by means of at least a protruding flap  18 , for example made so as to have one end connected to the elastic element  17 . 
     Preferably, each sliding contact element  15 ,  16  comprises a tab  25 ,  26  for connecting the sliding contact elements  15 ,  16  to a respective electric cable. 
     Preferably, the first sliding contact element  15  comprises a radial tab  25  for connection to an electric cable, which is inserted in an opening  35  made in the container  11  so as to make the first sliding contact element  15  integral with the container  11 ; the second sliding contact element  16  comprises an axial tab  26  for connection to an electric cable, which is inserted in the longitudinal recess  45  made in the tubular element  21  so as to make the second sliding contact element  16  integral with the tubular element  21 . 
     Preferably, the sliding contact elements  15 ,  16  and the elastic element  17  have an annular shape, for example of a perforated disk, with the tubular element  21  inserted inside them and the sliding contact elements  15 ,  16  can be rotated on their axis and superimposed on each other so as to slide on each other when the tubular element  21  and the container  11  are made to rotate relative to each other; in a known way, the sliding contact elements  15 ,  16  are made of conductive material, such as known brass or bronze alloys. 
     In order to achieve a better electrical contact between the first sliding contact element  15  and the second sliding contact element  16 , at least one contact area  31  projecting from the surface of the second sliding contact element  16  is preferably provided. 
     Each seat  12  comprises two walls  22  for containing an electrical connection element  14  and the openings  35  are formed between the two walls  22 . Preferably, the container  11  comprises a plurality of seats  12 , each containing an electrical connection element  14  inserted in the seat between the two walls  22  so as to compress the elastic element  17  to keep the first sliding contact element  15  and the second  16  sliding contact element  16  in contact; the tubular element  21  comprises a plurality of longitudinal recesses  45  for the passage of a respective electric cable. 
     In an embodiment of the electrical connection device  10  according to the invention, at least one seat  12  of the container  11  is configured to accommodate two electrical connection elements  14  for grounding the device  10 . 
     Preferably, the container  11  comprises two shells  36 , preferably fixed by means of fastening means, for example screws, and the openings  35  are made at the contact surface between the two shells  36 . 
     Preferably, the tubular element  21  comprises an annular protrusion  41  configured to fit into a circular seat  42  obtained in the container  11 , so as to form a guide which allows the tubular element  21  or the container  11  to rotate, one relative to the other. 
     In a first configuration, the electrical connection device  10  according to the invention comprises the fixed tubular element  21 , to constitute a stator, and the mobile container  11 , to constitute a rotor which can be connected to the mobile part of the apparatus to which the device  10  is connected. 
     Preferably, each elastic element  17  comprises a protrusion  27  mounted at the longitudinal tab  26  of each second sliding contact element  16  when the elastic element  17  and the sliding contact elements  15 ,  16  are superimposed to form the electrical connection element  14 , the protrusion  27  being inserted in the longitudinal recess  45  so as to keep the elastic element  17  integral with the second sliding contact element  16  and with the tubular element  21  which do not rotate. 
     In the operation of the electrical connection device  10  according to the invention in the first configuration, when the movable part of the apparatus rotates, the container  11 , connected to it, rotates with respect to the tubular element  21  on its longitudinal axis, dragging in its rotation the first sliding contact elements  15  connected to it by means of the respective radial tabs  25  inserted in the openings  35 , thus maintaining the electrical contact between the sliding contact elements  15 ,  16  thanks to the action of the elastic element  17 . 
     In a second configuration, the electrical connection device  10  according to the invention comprises the fixed container  11 , to constitute a stator, and the movable tubular element  21 , to constitute a rotor which can be connected to the movable part of the apparatus to which the device  10  is connected. 
     Preferably, each elastic element  17  comprises a protrusion (not shown in the figures) mounted at the radial tab  25  of each first sliding contact element  15  when the elastic element  17  and the sliding contact elements  15 ,  16  are superimposed to form the electrical connection element  14 , the protrusion being inserted into the opening  35  so as to keep the elastic element  17  integral with the first sliding contact element  15  and with the container  11  which do not rotate. 
     In the operation of the electrical connection device  10  according to the invention in the second configuration, when the movable part of the apparatus rotates, the tubular element  21 , connected to it, rotates with respect to the container  11  on its longitudinal axis, dragging in its rotation the second sliding contact elements  16  connected to it by means of the respective longitudinal tabs  26  inserted in the longitudinal recesses  45 , thus maintaining the electrical contact between the sliding contact elements  15 ,  16  thanks to the action of the elastic element  17 . 
     In an embodiment of the invention, the electrical connection element  14  further comprises a spacer element  67 , positioned between the elastic element  17  and a sliding contact element  15 ,  16 , preferably positioned between the elastic element  17  and the second sliding contact element  16 , and configured to ensure the correct operation of the elastic element  17  so as to ensure contact between the first and the second sliding contact elements  16 ,  15 , eliminating the play between the elements  17 ,  16 ,  15  of the electrical connection element  14 . 
     Preferably, the spacer element  67  has an annular shape, for example of a perforated disk, and the tubular element  21  is inserted inside it; preferably the spacer element  67  is made of plastic material, for example polyamides or polyamides loaded with glass fiber, polyvinylidene fluoride or polyetherimide. 
     Advantageously, the electrical connection device  10  of the invention allows you to electrically connect a fixed part and a mobile part of an equipment, ensuring good contact reliability over time, with reduced dimensions and costs. 
     A further advantage of the electrical connection device  10  in the embodiment of the invention which comprises the spacer element, is that of ensuring the correct work of the spring, thanks to the presence of the spacer element, without it being able to be packed in any way, and at the same time guarantee the contact between the sliding contact elements, eliminating the play.