Patent Publication Number: US-2007121932-A1

Title: Telephone with a Receiver Operated Reed Hook Switch

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application is a continuation-in-part of copending U.S. utility application entitled, “MAGNETIC HOOK SWITCH,” having Ser. No. 10/685,642, filed Oct. 15, 2003, which is entirely incorporated herein by reference. 
    
    
     TECHNICAL FIELD  
      This invention relates to a telephone having a receiver operated reed switch for placing the telephone in an on-hook state when the handset of the telephone is in the handset cradle and in an off-hook state when the handset is absent from the cradle. The reed switch is located in close proximity to the end of the handset having the receiver with a magnet either as an integral part of the receiver or as a separate component specifically to provide a magnetic flux for operating the reed switch.  
     BACKGROUND OF THE INVENTION  
      Mechanical switches have been used for many years to place a telephone either on-hook or off-hook state. This mechanical switch has typically been a tongue which is used to activate an electrical switch to put the telephone in an on-hook or off-hook state.  
      This tongue assembly is subject to malfunction and abuse by users of the telephone. This is particularly a problem in prisons and jails where telephones are placed for outgoing calls for the benefit of inmates. The tongue of the telephone is frequently abused by prisoners slamming the telephone handset onto the tongue assembly. The tongue assembly is sometimes used by prisoners as a switch to actually make a telephone call. Elimination of the tongue assembly in the telephone housing will significantly reduce the amount of moisture, cleaning fluids and other liquids that previously would have entered the housing through the opening. If the tongue assembly is eliminated then the opening will not be necessary either.  
     SUMMARY OF THE INVENTION  
      The present invention is a telephone having a reed switch for placing the communication line to the telephone in either an on-hook or off-hook state. The telephone of this invention has a handset with two ends with one end having a microphone and the other end having a receiver with an integral magnet which provides a magnetic flux in the operation of the receiver. The reed switch is located in the cradle or in close proximity to the cradle attached to the base unit of the telephone. When the end of the handset with the receiver is placed in the cradle, the magnetic flux provided by the integral magnet of the receiver activates the reed switch. In order to be effected by the integral magnet in the receiver end of the handset, the reed switch must be located in the cradle or in close proximity to the cradle in which the handset rests in the on-hook state. The reed switch can be located inside a cavity on one side of the cradle. Alternatively, the reed switch can be located on the inside of the front of the base unit of the telephone or on a separate plate covering the hole where the tongue of the telephone was previously located. Preferably, the reed switch is encapsulated in a protective material such as a thermoplastic and affixed to a cavity in one side of the cradle.  
      Preferably, the reed switch is located so that it is in the on-hook position when the end of the handset with the receiver is in the handset cradle. However, the reed switch can be positioned in the off-hook position under these circumstances with the circuit board of the base unit designed to place the communication line in an on-hook position in this position. The reed switch is typically sealed in an inert gas ampoule which is encapsulated in a thermoplastic material.  
      The reed switch used in this invention can be used with electronic telephones that do not have a magnet as part of the receiver in the handset. Under those circumstances, a magnet with sufficient power to operate the reed switch is placed in the end of the handset with the receiver.  
      The reed switch can perform the on-hook/off-hook switching of either a conventional or electronic telephone. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
       FIG. 1  is a perspective view of the unassembled telephone of this invention.  
       FIG. 2  is a perspective view of the telephone of this invention in which the cradle has been installed and the handset is in place in the cradle.  
       FIG. 3  is a front view of the telephone of this invention with the handset in the cradle.  
       FIG. 4  is a back view of the telephone of this invention with the reed switch attached to a separate plate prior to assembly of the telephone. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Inmates in prisons frequently abuse the pay telephones made available to them by slamming the telephone handset onto the tongue of the telephone when they are angry. This sometimes damages or destroys the tongue assembly making the telephone inoperable. They also sometimes try to remove the tongue from the telephone to make a utensil or weapon.  
      Clever inmates have discovered that they can call a number without any money being paid for the call by depressing and releasing the tongue in the right sequence and timing to duplicate the dialing of the number on the key pad on an analog telephone. Skilled inmates can dial as fast in this way as with the key pad.  
      The telephone of this invention eliminates the possibility of this abuse of the equipment and defrauding the telephone service provider of revenue. This invention replaces the telephone tongue assembly with a reed switch which connects and disconnects the telephone from the outside communication line based upon the proximity of the receiver of the handset to cradle of the telephone where the reed switch is located. The reed switch is activated by the magnet which is an inherent part of the receiver of the handset of the telephone. Thus, there is no tongue assembly to abuse and it is not possible to dial a number by manipulating the reed switch as it is located within the telephone.  
       FIGS. 1-3  illustrate one embodiment of the telephone of this invention. The telephone  1  includes a conventional housing  3  which has a front wall  5  with a keypad  7 . Attached to the housing  3  is a cradle  9  which has two sides  11 ,  13 . The cradle  9  has threaded holes  15  for use in attachment of the cradle  9  to the housing  3 . A separate plate  17  is installed in the housing  3 . Plate  17  has plurality of holes  19  which are aligned with the threaded holes  15  in the cradle  9 . The cradle  9  is attached to the housing  3  by a plurality of studs  21  which extend through the holes  19  in plate  17  and into the threaded holes  15  of the cradle  9 . The telephone  1  has a handset  25  with a receiver  27  and microphone  29 . The magnet  31  is an integral part of the receiver  27 . This magnet  31  generates a magnetic field around the receiver  27 .  
      A reed switch  33  is installed in one side  11  of the cradle  9 . The reed switch  33  generally consists of two elongated metallic contacts that are sealed in the inert gas of an ampoule. The magnetic field generated by the magnet  31  of the receiver  27  will affect the contacts in the reed switch  33  by either bringing them into contact or breaking the contact depending on how the reed switch is constructed. The reed switch  33  must be placed in close proximity to the magnet  31  of the receiver  27  in order to be affected by the magnetic field of the magnet  31 . One convenient place to locate the reed switch  33  is in a cavity  23  on one side  11  of the cradle  9 . Thus, when the handset  25  is placed in the cradle  9 , the magnet  31  in the receiver  27  is in close proximity to the reed switch  33 . Preferably, the reed switch  33  is encapsulated in a plastic material that secures it and affixes it in the cavity  23  of the cradle  9 . The reed switch  33  has two electrical leads  35  with each being attached to an outside communication line (not shown) and the cord  23  attached to the handset  25 .  
      When the receiver  27  of the handset  25  is placed in the cradle  9  the magnetic effect of the magnet  31  breaks the contact between the contacts in the reed switch  33  which places the telephone in an on-hook status. Alternatively, the reed switch  33  can be constructed so that contact is made when the receiver  27  is in the cradle  9 . A circuit board (not shown) controls the operation of the reed switch so that the telephone is in an on-hook status when the receiver  27  is in the cradle  9  and is in an off-hook status when the receiver  27  is out of the cradle  9 . This telephone houses a conventional circuit board for controlling its operations.  
      It has been learned that the reed switch generally has to be placed approximately ¼ inch from the magnet  31  which is an integral part of the receiver in a conventional telephone.  
       FIG. 4  represents an alternative embodiment for placement of the reed switch  33 . In this case, the reed switch  33  is placed on a separate plate  17  which is installed on the front wall  5  of the telephone  1  in close proximity to the magnet  31  of the receiver  27 . It should be realized that it is not necessary to have plate  17  as the cradle  9  could be installed directly on the front wall  5  of the housing  3 . In this case, the reed switch  33  could be placed on the back surface of the front wall  5  of the housing  3  in close proximity to the receiver  27 . If the reed switch  33  is installed on the plate  17  or on the back of the front wall  5 , it is preferable that it be encapsulated in a plastic material to protect it from damage and corrosion.  
      The reed switch used in the telephone of this invention can also be used with an electronic telephone with a digital microphone and receiver by providing a magnet in the end of the handset having the receiver. This magnet will provide the necessary magnetic field to affect the reed switch  33  located in close proximity to it.