Abstract:
A device for connecting and insulating a thermal protector for electrical winding of motors, comprising a tray-like shell made of a plastic material, which contains the protector and is provided with one or more terminals for electrical contact with the power supply of the motor to which it is applied; the contacts protrude from the shell, which has one or more tabs and locators which are applied by anchoring, in suitable and complementary regions of the spools of the windings of the motor enclosed in a plastic cover.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a device for connecting and insulating a thermal protector for electrical windings of motors. 
     It is known that in the mass-production of electric motors, manufacturers have a growing need to automate their processes in order to achieve considerable economies of scale. 
     However, this need clashes with the fact that in the electrical field many technologically developed countries have rather restrictive standards in order to ensure the quality and safety of the product. 
     Accordingly, the need to combine high quality and safety with large production runs induces operators in this field to develop solutions aimed at assembling components on automatic machines. 
     In particular, one very important component of the protection means of an electric motor is the thermal protector and particularly its connection and insulation. 
     The thermal protector is substantially constituted by a component that is sensitive to the temperature variations of the windings of the motor and ensures that said windings, once a preset temperature has been reached, are disconnected from the contacts to the electric power supply. 
     The thermal protectors currently applied to motors are substantially connected by means of clinched or soldered wires which are then insulated by means of heat-shrink sheaths and positioned manually, and therefore it is necessary to provide a specialized operator dedicated to the wiring and to assembling said thermal protector. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to provide a device for connecting and insulating a thermal protector for electrical windings of motors that ensures automated assembly without however sacrificing the safety and quality assurances of the final product. 
     Within this aim, an important object of the present invention is to provide a device for connecting and insulating a thermal protector that ensures complete absence of significant interference regarding the properties of detection and sensitivity to thermal variations of the winding. 
     Another object of the present invention is to provide a device for connecting and insulating a thermal protector whose structure ensures high flexibility of application as regards both the shape and size. 
     Another object of the present invention is to provide a device for connecting and insulating a thermal protector whose structure also allows application to motor types that are already in production and have already been developed. 
     Another object of the present invention is to provide a device for connecting and insulating a thermal protector whose structure allows its easy replacement in case of malfunction and allows to manufacture it through known technologies and systems. 
     This aim and these and other objects that will become better apparent hereinafter are achieved by a device for connecting and insulating a thermal protector for electrical winding of motors, characterized in that it comprises a tray-like shell made of a plastic material which contains the protector and is provided with one or more terminals for electrical contact with the power supply of the motor to which it is applied, said contacts protruding from said shell, said shell having one or more tabs and locators which are adapted to be applied by anchoring, within suitable and complementary regions of the spools of the windings of the motor enclosed in a plastic cover. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further characteristics and advantages of the invention will become better apparent from the description of an embodiment thereof and of various applicative situations, illustrated only by way of non-limitative example in the accompanying drawings, wherein: 
     FIG. 1 is a partially sectional orthographic projection view of a device for connecting and insulating a thermal protector having the structure according to the invention; 
     FIGS. 2 and 3 are two orthographic projection views of the device of FIG. 1; 
     FIGS. 4 and 5 are two partially sectional orthographic projection views of the device of FIG. 1 in a particular applicative situation; 
     FIGS. 6 and 7 are two partially sectional orthographic projection views of the device of FIG. 1 in another applicative situation; 
     FIGS. 8 and 9 are two partially sectional orthographic projection views of the device in yet another applicative situation; 
     FIGS. 10 and 11 are two partially sectional orthographic projection views of the device in yet another applicative situation; 
     FIG. 12 is a view of a component of FIGS.  10  and  11 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With particular reference to FIGS. 1 to  3 , a device for connecting and insulating a thermal protector for electrical windings of motors having the structure according to the invention is generally designated by the reference numeral  10 . 
     The device  10  comprises, within a rigid tray-like shell  11  made of plastics, a thermal protector  12  (a component that is sensitive to temperature variations), which has, in this case, two terminals  13 , described in greater detail hereinafter, for electrical contact with the power supply of the electric motor  15 , as specified in greater detail hereinafter, which protrude from the shell  11 . 
     The shell  11  has, in this case, positioning tabs and locators, as described in greater detail hereinafter, which are suitable to be applied in anchoring within suitable and complementary portions of the plastic cover  16  of the motor  15 . 
     The shell is conveniently placed in contact with the windings  14 , so that the thermal protector  12  is adjacent thereto and can detect its temperature. 
     In this embodiment, the electrical contact terminals  13  are constituted by a corresponding number of laminas  17  that protrude from the shell  11  and are partially accommodated and rest in suitable channels  18  formed in said shell  11 . 
     The shell  11  is shaped, at the edge  19  related to the access opening designated by the reference numeral  20 , so as to form in this case two elastic cantilevered tongues  21  for reversible locking of the thermal protector  12 . 
     In this embodiment, said tabs are constituted by a tooth  22  which protrudes from said shell  11  in the vicinity of said electrical contact terminals  13  and substantially at right angles to the arrangement of the thermal protector  12 ; said tooth is suitable to enter an appropriately provided seat  23  formed in a head  23   a  of the spool  35  for the windings  14  of said electric motor. 
     In this embodiment, the device  10  is further provided with a cover  24  for the reversible closure of the shell  11 . 
     In particular, the cover  24  is substantially monolithic with the shell  11 , to which it is pivoted with a side-hinged movement by way of a longitudinal flexible articulation portion  25 . 
     The cover  24  also has a coupling  26  for reversible engagement with a locking tooth  27 . 
     The cover  24  has a centering locator  28 . 
     In particular, the described embodiment is particularly useful for motors intended for example for vacuum cleaners. 
     In motors intended for example for application in pumps it is instead better to provide the solution without a cover. 
     With particular reference to FIGS. 4 and 5, the device  10  is applied to an electric motor  15 , which is provided with a particular connector  29  (in a plastic cover  33 ), which accommodates electrical terminals  30  for connection to the windings  14 . 
     In particular, the figures show the position of the protector  12 , which is substantially perpendicular to the electrical terminals  30 , to which it is connected by means of the laminas  17 . 
     In this case, the cover  33  of the motor  15  has feet  34 , which keep the thermal protector  12  pressed against the bottom of the shell  11 . 
     The application of a device  10  in a motor generally designated by the reference numeral  115  is described with particular reference to FIGS. 6 and 7. 
     Here, too, attention is called to the particular configuration of the connection between the protector  12  and, inside a connector  131  of the cover  133 , electrical terminals  132  for connection to the windings  114 . 
     In this case, the cover  133  of the motor  115  has feet  134 , which keep the sensor element  12  pressed against the bottom of the shell  11 . 
     The application of a device  10  to an electric motor  215  is described with particular reference to FIGS. 8 and 9. 
     In particular, the above cited figures show the particular shape of the connection between the protector  12  and, within a particular connector  233 , electrical terminals  234  for connection to the windings  214 . 
     With particular reference to FIGS. 10 and 11, the device  10  is applied to an electric motor  315  that has a connector  329  (in a cover  333  made of plastics) that accommodates electrical terminals  330  for connection to the windings  314 . 
     The protector  12  is substantially perpendicular to the electrical terminals  330 , to which it is connected by means of the laminas  17 . 
     FIG. 12 illustrates the spool  335 , which is arranged in a configuration suitable for the winding of the windings  314  of the motor  315 . 
     A plate-like wing  336  protrudes monolithically at the head  335   a  of the spool  335 ; said wing is normally parallel to the protector  12  and lies below the laminas. 
     The wing  336  can be folded so as to be parallel to the electrical terminals  330  because it is connected to the head  335   a  by means of a film hinge  337 . 
     When the wing  336  is folded so as to be parallel to the terminals  330  and the spool  335  is arranged in the active configuration, said wing is interposed between said electric terminals  330 , as shown in FIG. 10, preventing any short-circuit contacts thereof due to the laminas  17  that protrude from the protector  12 . 
     The presence of the wing  336  is particularly important when the electrical terminals ( 30 ,  130 ,  330 ) are substantially aligned with the direction of extension of the laminas  17 . 
     In practice it has been found that the present invention has achieved the intended aim and objects. 
     It is in fact noted that despite the constructive simplicity of the structure of the device according to the invention, a high capacity for automation, even mass automation, is provided without detracting from the safety of the positioning and connection of said protector. 
     The assembly of the protector is in fact substantially guided and substantially free from possibilities of assembly errors owing to its structure. 
     It should also be noted that the particular structure of the protector allows to place said protector in an optimum situation for detecting effectively the temperature variations of the winding. 
     It is also noted that the structure of the shell of the thermal protector allows high flexibility of application both in terms of shape and in terms of size in relation to the motor for which it is intended. 
     Finally, it should be noted that the structure of the device according to the invention allows easy and immediate replacement without particular technical expertise on the part of the operator. 
     The present invention is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. 
     The technical details can be replaced with other technically equivalent elements. 
     The materials and the dimensions may be any according to requirements. 
     The disclosures in Italian Utility Model Application No. PD2001U000016 from which this application claims priority are incorporated herein by reference.