Publishing Venue
Motorola
Related People
Authors:
Christopher R. Long
•
Michael Bent
Abstract
The smaller size of today's pagers also reduces their weight proportionately. Traditional charger and progmm- mer devices have always relied on gravity to provide suffkient resistance force to spring loaded z-axis inter- connect pins that access electrical contacts on the bot- tom of the pager housing. The number of these interconnect pins has increased as more products utilize these pins for hmctions other than charging only (B+ and GND). Data transmission and external antenna porting through these contacts is also now common. Typical pagers now weigh less than 95 grams. Dividing this weight among three or more pins puts the force per pin at an unacceptably low level, less than the recom- mended loo-125 gram minimum for low current, point contact connectors. This device provides a means to lock a pager into the housing so that contact forces can be increased. Other methods of locking a unit into a charger require two handed operation to remove the pager since one hand is required to push back a latch while the other removes the pager. This device allows one handed oper- ation to remove the pager.
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MOTOROLA INC. Technical Developments Volume 16 August 1992
ONE HANDED LOCK MECHANISM FOR CHARGERS
by Christopher R. Long and Michael Bent
The smaller size of today's pagers also reduces their weight proportionately. Traditional charger and progmm- mer devices have always relied on gravity to provide suffkient resistance force to spring loaded z-axis inter- connect pins that access electrical contacts on the bot- tom of the pager housing. The number of these interconnect pins has increased as more products utilize these pins for hmctions other than charging only (B+ and GND). Data transmission and external antenna porting through these contacts is also now common. Typical pagers now weigh less than 95 grams. Dividing this weight among three or more pins puts the force per pin at an unacceptably low level, less than the recom- mended loo-125 gram minimum for low current, point contact connectors. This device provides a means to lock a pager into the housing so that contact forces can be increased. Other methods of locking a unit into a charger require two handed operation to remove the pager since one hand is required to push back a latch while the other removes the pager. This device allows one handed oper- ation to remove the pager.
The device relies on a pin and track mechanism sometimes found in push button switches. In the inte-
rior of the charger housing cavity, a spring loaded pin protrudes. On the back of the pager housing, there is a series of grooves and channels (Figure 1) of varying depth. As the pager is inserted into the charger housing, the pin aligns with the beginning of the channel system at point 'A" (Figures 1 and 2). As the unit is pushed fur- ther into the cavity, the pin travels up the channel fol- lowing the designed routing. As the pager bottoms out in the cavity, the pi...
