The advantage of being able to remove the hook switch bodily from the other portions arises mainly in connection with the shipment or transportation of instruments.  The projecting hooks cause the instruments to take up more room and thus make larger packing boxes necessary than would otherwise be used.  Moreover, in handling the telephones in store houses or transporting them to the places where they are to be used, the projecting hook switch is particularly liable to become damaged.  It is for convenience under such conditions that the Dean hook switch is made so that the switch lever may be removed bodily and placed, for instance, inside the telephone box for transportation.

Desk-Stand Hooks.  The problem of hook-switch design for portable desk telephones, while presenting the same general characteristics, differs in the details of construction on account of the necessarily restricted space available for the switch contacts in the desk telephone.

[Illustration:  WEST OFFICE OF HOME TELEPHONE COMPANY, SAN FRANCISCO Serving the General Western Business and Residence Districts.]

Western Electric. In Fig. 86 is shown an excellent example of hook-switch design as applied to the requirements of the ordinary portable desk set.  This figure is a cross-sectional view of the base and standard of a familiar type of desk telephone.  The base itself is of stamped metal construction, as indicated, and the standard which supports the transmitter and the switch hook for the receiver is composed of a black enameled or nickel-plated brass tube 1, attached to the base by a screw-threaded joint, as shown.  The switch lever 2 is pivoted at 3 in a brass plug 4, closing the upper end of the tube forming the standard.  This brass plug supports also the transmitter, which is not shown in this figure.  Attached to the plug 4 by the screw 5 is a heavy strip 6, which reaches down through the tube to the base plate of the standard and is held therein by a screw 7.  The plug 4, carrying with it the switch-hook lever 2 and the brass strip 6, may be lifted bodily out of the standard 1 by taking out the screw 7 which holds the strip 6 in place, as is clearly indicated.  On the strip 6 there is mounted the group of switch springs by which the circuit changes of the instrument are brought about when the hook is raised or lowered.  The spring 8 is longer than the others, and projects upwardly far enough to engage the lug on the switch-hook lever 2.  This spring, which is so bent as to close the contacts at the right when not prevented by the switch lever, also serves as an actuating spring to raise the lever 2 when the receiver is removed from it.  This spring, when the receiver is removed from the hook, engages the two springs at the right, as shown, or when the receiver is placed on the hook, breaks contact with the two right-hand springs and makes contact respectively with the left-hand spring and also with the contact 9 which forms the transmitter terminal.