Cordless electrical appliances

Abstract

A cordless electrical appliance includes a male pin connector which engages vertically with a female socket connector mounted in a base for the appliance. The contacts are arranged such that one of the line or neutral connections makes last and breaks first. This connection includes a silver, copper backed contact mounted on a leaf spring with a corresponding male pin being made of copper and having a thin silver plating at least in a region of contact with the copper backed contact.

I claim: 
     
       1. An electrical appliance and base comprising: an electrical appliance including a male pin connector;   a base for the appliance, the base including a female socket connector which is arranged to be engaged by the male pin connector when the appliance is placed on the base; and   at least one electrical connection between the male pin and female socket connectors being formed by a leaf spring mounted silver faced contact with a corresponding male pin, the male pin being made, at least in contact forming region thereof, of copper, the male pin wiping against the silver faced contact during engagement and disengagement of the female socket connector and the male pin connector so that silver from the silver faced contact is transferred to the pin.   
     
     
       2. An appliance and base as claimed in claim 1 wherein the copper is industrially pure copper. 
     
     
       3. An appliance and base as claimed in claim 1 wherein the copper has a hardness of from 70 to 95 HV. 
     
     
       4. An appliance and base as claimed in claim 1 wherein the male pin is punched out of copper. 
     
     
       5. A appliance and base as claimed in claim 1 having line and neutral connections, wherein both the line and neutral connections are formed by leaf spring mounted silver faced contacts, and corresponding male pins, the male pins being made, at least in contact forming regions thereof, of copper. 
     
     
       6. An appliance and base as claimed in claim 1 or 5 having line and neutral connections between male pin and female socket connectors wherein the line and neutral connections are offset in a direction of engagement and disengagement for sequential making and breaking of the line and neutral connections, and at least a connection last to make and first to break includes a silver faced contact mounted on a leaf spring, an associated male pin being made, at least in a contact making region thereof, of copper. 
     
     
       7. An appliance and base as claimed in claim 1 wherein the male pin is provided with a thin coating of silver extending over at least the contact forming region thereof. 
     
     
       8. An appliance and base as claimed in claim 7 wherein the thickness of the coating is from about 3 to about 5 microns. 
     
     
       9. An appliance and base as claimed in claim 1 wherein the appliance further includes a thermally-sensitive control unit having terminal pins extending, during normal use, horizontally from a lower rear part of the appliance. 
     
     
       10. An appliance and base as claimed in claim 9 wherein the female socket connector includes slots in an upper and forwardly facing surface thereof whereby the horizontally extending pins of the control unit are receivable vertically for engagement with spring contacts of the female socket connector. 
     
     
       11. An electrical connector comprising a male pin connector and a female socket connector, the socket connector including at least one spring mounted, silver faced contact, and the male pin connector including a corresponding terminal pin which is formed of copper at least in a region thereof adjacent a point of engagement in use with the socket connector contact, the male pin wiping against the socket connector contact during engagement and disengagement of the female socket connector and the male pin connector so that the silver from the socket connector contact is transferred to the pin. 
     
     
       12. A portable electrical water heating appliance and base comprising: a water heating appliance including a thermally sensitive control unit having terminal pins; and   a base for receiving the appliance, the base including a female socket connector for receiving the terminal pins,   wherein at least one of the terminal pins is formed, in at least a contact forming region thereof, of industrially pure copper, the contact forming region further having a thin silver coating, the female socket connector having a spring mounted silver faced contact for engagement with the contact forming region of the terminal pin, the terminal pin wiping against the silver contact during engagement and disengagement of the female socket connector and the terminal pin so that silver from the contact is transferred to the terminal pin.   
     
     
       13. An appliance and base as claimed in claim 12 wherein, in use, the terminal pins extend horizontally at a lower rear part of the appliance, and the socket connector is configured to receive the pins vertically. 
     
     
       14. An appliance and base as claimed in claim 12 or 13 wherein the coating is between about 3 and 5 microns in thickness. 
     
     
       15. A connector as claimed in claim 11 wherein the terminal pin has a thin coating of silver over a contact forming region thereof. 
     
     
       16. A connector as claimed in claim 15 wherein the coating is between about 3 and 5 microns in thickness. 
     
     
       17. An electrical appliance and base comprising: an appliance including a thermally sensitive control unit including terminal pins;   a base for receiving the appliance, the base including a female socket connector for receiving the terminal pins so that line and neutral connections are made therewith,   wherein an arrangement of the pins and base contacts arranged within the base is offset in a direction of engagement and disengagement such that engagement of the respective pins with the respective base contacts is staggered, a connection making last and breaking first being made between a thinly silver coated copper terminal pin and a leaf spring mounted silver faced contact, the terminal pin wiping against the silver contact during engagement and disengagement of the female socket connector and the terminal pin so that silver from the contact is transferred to the terminal pin.   
     
     
       18. An electrical appliance and base comprising: an electrical appliance including a male pin connector;   a base for the appliance, the base including a female socket connector which is arranged to be engaged by the male pin connector when the appliance is placed on the base; and   at least one electrical connection between the male pin and female socket connectors being formed by a leaf spring mounted copper backed silver contact with a corresponding male pin, the male pin being made, at least in a contact forming region thereof, of copper, the male pin wiping against the silver contact during engagement and disengagement of the female socket connector and the male pin connector so that silver from the contact is transferred to the pin. .Iadd.   
     
     
       19.  An electrical appliance including a housing having a male pin connector and also including a base having a female socket connector which is arranged to be engaged by said male pin connector when the appliance housing is vertically inserted downwardly on the base, the male pin connector comprising line, neutral and earth pins extending generally horizontally at the lower rear part of the appliance housing, and the female socket connector including female contacts comprising a plurality of leaf springs, each extending upwardly through the female socket connector and having an upwardly facing contact surface provided on its upper end for engagement with a corresponding male pin, and vertically offset from one another for sequential engagement and disengagement with the male pins..Iaddend..Iadd.20. An electrical appliance housing an base as claimed in claim 19 wherein the female contact which is last to engage with a male pin is first to disengage with said male pin and comprises a 
     
     
        spring mounted member..Iaddend..Iadd.21.  An electrical appliance housing and base as claimed in claim 20 wherein the female contact which is last to engage with a male pin is first to disengage with said male pin and comprises a contact member mounted on a leaf spring, and further comprising another female contact including a leaf spring without a contact member mounted thereon..Iaddend..Iadd.22. An electrical appliance housing and base as claimed in claim 19, 20 or 21 wherein the male pin connector part of the connection last to make and first to break comprises a silver coated pin..Iaddend..Iadd.23. An electrical appliance housing and base as claimed in claim 19 further comprising a male earth pin which engages with an earth contact in the female socket connector prior to engagement by the male line pin and the male neutral pin with the corresponding line or neutral contacts in the female socket connector when 
     
     
        the appliance housing is placed on the base..Iaddend..Iadd.24.  An electrical appliance housing and base of claim 19 further comprising a centering recess and centering ridge on respective appliance housing and base to align the pins and springs..Iaddend..Iadd.25. An electrical appliance housing and base of claim 19 further comprising walls separating the female contacts..Iaddend..Iadd.26. An electrical appliance housing and base of claim 19 further comprising separate compartments for the female contacts..Iaddend.