Pneumatic carrier system with station control

Claim 2

In a station-controlled pneumatic carrier system having at least two spaced-apart stations a control system comprising, in combination: a destination selector at each station, physically independent of a carrier, for selecting the destination for a carrier inserted into the pneumatic carrier system at the station; a central controller associated with at least said two stations for controlling the pneumatic carrier system; signal means at each station for signalling said central controller when a carrier is ready to be sent from the station; and said central controller including an interrogation circuit for determining the destination station to which a carrier is to be sent pursuant to selection thereof by its associated destination selector, said interrogation circuit being operative to transmit to said associated station selector an interrogate signal and monitor the response thereto to thereby determine the identity of said destination station selected by said associated station selector, said central controller including a selector circuit for selectively connecting to said interrogation circuit only one station at a time in response to a signal from said signal means at a station.

Claim 3

The control system of claim 1 additionally including a receiving station activation means responsive to said interrogation cirCuit for conditioning for carrier receipt the destination station indicated by the destination selector of the station to which the interrogation circuit is connected by the selector circuit.

Claim 4

The control system of claim 2 additionally including dispatch means for transmitting the carrier from said connected station to the station indicated by the destination station selector at said connected station when said destination station has been conditioned for receipt of a carrier by said activation means.

Claim 5

A pneumatic system for transmitting carriers between remotely located stations comprising, in combination: a first pneumatic loop with a plurality of stations disposed along the length of said first loop; a second pneumatic loop with a plurality of stations disposed along the length of said second loop; a pneumatic interconnection between said first and second loop permitting carriers to be transmitted from one loop to the other; a first independent loop controller to control the pneumatic transfer of carriers between stations on said first loop; a second independent loop controller to control pneumatic transfer of carriers between stations on said second loop; interconnection controls in said first and second loop controllers for communicating between said controllers to control said first pneumatic loop, said second pneumatic loop and said interconnector to permit transfer of carriers from a station on one loop to a station on the other loop; station selector means at each station to select the destination for carriers transmitted from the station; and an interrogation circuit at each controller for determining, from an interrogate signal transmitted to a station, the station selected on said station selector means at the station receiving said interrogate signal.

Claim 6

A pneumatic system for transmitting carriers between remotely located stations comprising, in combination: a first pneumatic loop with a plurality of stations disposed along the length of said first loop; a second pneumatic loop with a plurality of stations disposed along the length of said second loop; a pneumatic interconnection between said first and second loop permitting carriers to be transmitted from one loop to the other; a first independent loop controller to control the pneumatic transfer of carriers between stations on said first loop; a second independent loop controller to control pneumatic transfer of carriers between stations on said second loop; interconnection controls in said first and second loop controllers for communicating between said controllers to control said first pneumatic loop, said second pneumatic loop and said interconnector to permit transfer of carriers from a station on one loop to a station on the other loop; station selector means at each station to select the destination for carriers transmitted from the station; and an interrogation circuit at each controller for determining, from an interrogate signal transmitted to a station, the station selected on said station selector means at the station receiving said interrogate signal.

Claim 7

The pneumatic system of claim 4 wherein each controller includes a receiving station activator circuit to condition for receipt of a carrier the station determined by said interrogation circuit to receive a carrier.

Claim 8

The pneumatic system of claim 5 wherein each controller includes a sending station activator circuit to dispatch a carrier from a station after the desired destination station has been conditioned to receive a carrier.

Claim 9

A control system for a single loop station controlled pneumatic carrier system comprising, in combination. a plurality of stations disposed around the pneumatic loop, each station including a destination address selecting means and a signalling means to signal that the station is conditioned to send a carrier; a sender control unit; a control wire uniquely associated with said said station for connecting said signalling means at the station with said sender control unit; an interrogate wire for connecting said destination address selecting means with said sender control unit; an address reader; and a common control wire connected at one end to said sender control unit and at its other end to said address reader; said sender control unit being operative to connect the destination address means at only one station to said common control wire when said signalling means at said one station signals on said associated control wire that said one station is conditioned to send a carrier; said address reader including an alternating current signal source connected to said common control wire, said alternating current source producing an output having an amplitude stepwise increasing with time and means to detect predetermined current levels for said alternating current signal, the setting of said destination address selection means at the station connected to said address reader by said sender control unit being operative to control the amplitude of said alternating current signal at which said predetermined current level occurs.

Claim 10

A control system for a single loop station controlled pneumatic carrier system comprising, in combination. a plurality of stations disposed around the pneumatic loop, each station including a destination address selecting means and a signalling means to signal that the station is conditioned to send a carrier; a sender control unit; a control wire uniquely associated with said said station for connecting said signalling means at the station with said sender control unit; an interrogate wire for connecting said destination address selecting means with said sender control unit; an address reader; and a common control wire connected at one end to said sender control unit and at its other end to said address reader; said sender control unit being operative to connect the destination address means at only one station to said common control wire when said signalling means at said one station signals on said associated control wire that said one station is conditioned to send a carrier; said address reader including an alternating current signal source connected to said common control wire, said alternating current source producing an output having an amplitude stepwise increasing with time and means to detect predetermined current levels for said alternating current signal, the setting of said destination address selection means at the station connected to said address reader by said sender control unit being operative to control the amplitude of said alternating current signal at which said predetermined current level occurs.

Claim 11

The control system for a single loop station-controlled pneumatic carrier system of claim 7 wherein each said destination address selectiNg means comprises, in combination: a plurality of single pole, single throw electrical switches normally open-circuited, each said electrical switch including two switch contacts, one of said switch contacts being connected to said interrogate wire; said plurality of electrical switches including a pair of electrical switches each having its other contact wired to ground through a unidirectional current conducting element, the direction of current flow permitted from said interrogate wire through said pair of electrical switches being opposite in direction due to opposite arrangement of said unidirectional current conducting elements; said plurality of electrical switches including other pairs of electrical switches each having its other contact wired to a unidirectional current conducting element arranged to permit different direction of current flow through each electrical switch in each said other pair, the other lead of each unidirection current conducting element associated with a given other pair of electrical switches being connected to ground through a resistance path, the resistance path associated with each other pair of switches having a different electrical resistance from other said resistance paths.

Claim 12

The control system for a single loop station-controlled pneumatic carrier system of claim 8 wherein said destination address selecting means comprises in combination an additional address selecting means as defined in claim 2 and an additional switch means controllable from the sender control unit to select which destination address selecting means is connected to said interrogate wire.

Claim 13

The control system for a single loop station-controlled pneumatic carrier system of claim 7 wherein said alternating current source for producing a signal with an amplitude stepwise increasing with time comprises: an alternating current source; a plurality of signal clipping elements for clipping the signal from said alternating current source to form a plurality of square wave signals with different amplitudes; and a time base selector for connecting the outputs of each signal clipping element to said alternating current source output in sequence to provide said alternating current signal with an amplitude stepwise increasing with time.

Claim 14

The control system for a single loop station-controlled pneumatic carrier system of claim 10 wherein each said signal clipping element comprises a pair of back-to-back connected Zener diodes with one lead of said connected pair of Zener diodes being connected to said alternating current source and the other lead providing one said square wave signal.

Claim 15

The control system for a single loop station-controlled pneumatic carrier system of claim 7 wherein said predetermined current level detector comprises, in combination: a positive pulse current monitor and a negative pulse current monitor; and a current level switch responsive to each current level monitor, each said current level switch being activated when the connected current monitor detects a predetermined current.

Claim 16

The control system for a single loop station-controlled pneumatic carrier system of claim 12 wherein each said current monitor comprises a photosensor.

Claim 17

The control system for a single loop station-controlled pneumatic carrier system of claim 13 wherein each said current level switch comprises a Schmitt trigger circuit responsive to one said photosensor.

Claim 18

The control system for a single loop station-controlled pneumatic carrier system of claim 7 additionally including a destination address storage means responsive to said address reader for storing the address read from the station destination address selecting means by said address reader.

Claim 19

The control system for a single loop station-controlled pneumatic carrier system of claim 15 including a destination station selector responsive to said destination address storage means for conditioning the destination station defined by the destinAtion address to receive a pneumatic carrier from the pneumatic loop.

Claim 20

The control system for a single loop station-controlled pneumatic carrier system of claim 7 wherein said destination address selection means at each station includes a group selection means and a unit selection means, said group selector for selecting the group in which the destination is located and said unit selector for selecting the unit within the selected group.

Claim 21

The control system for a single loop station-controlled pneumatic carrier system of claim 17 additionally including a destination address storage means responsive to the address reader for storing the group number and the unit number read from the destination address selector means by the address reader.

Claim 22

The control system for a single loop station-controlled pneumatic carrier system of claim 18 including a destination station selector responsive to said destination address storage means for conditioning the destination station defined by the destination address to receive a pneumatic carrier from the pneumatic loop.

Claim 23

The control system for a single loop station-controlled pneumatic carrier system of claim 19 wherein said destination station selector includes a pair of code wires connected to each station in each group, a code generator responsive to the unit number stored in said storage means and a selector switch responsive to group number stored in said storage means to connect said code generator to the pair of code wires corresponding to the group numbers stored in said storage means.

Claim 24

The control system for a single loop station-controlled pneumatic carrier system of claim 20 wherein each station in a group of stations includes a receiver responsive to said pair of code wires to energize the receiver station upon recognizing a unique code on said pair of code wires.

Claim 25

The control system of claim 19 additionally including a second control system like that defined by claim 13 for controlling a second pneumatic loop, the group numbers associated with stations on one pneumatic loop being different from the group number for stations on the second pneumatic loop; a loop interconnector circuit for transmitting the unit number from the storage means of one loop to the pair of code wires at the other loop having a group number corresponding to the group number stored in the storage means for said one loop.