US797053A - Pneumatic-despatch-tube apparatus. - Google Patents

Description

PATENTED AUG. 15, 1905.

E. A. FORDYGE. PNEUMATIC DBSPATCH TUBE APPARATUS.

APPLICATION FILED MAY 31,1904.

6 SHEETS-SHEET 1.

PATENTED AUG. 15, 1905.

E. A. FORDYGE. PNEUMATIC DESPATGH TUBE APPARATUS.

APPLICATION FILED MAY 31,1904.

6 SHEETS-SHEET 2.

PATENTED AUG. 15, 1905 E. A. PORDYGB. PNEUMATIC DESPATGH TUBE APPARATUS.

APPLIGATION FILED MAY 31,1904.

6 SHEETS-SHEET 3.

No. 797,053. PATENTED AUG. 15, 1905. E. A. FORDYGE.

PNEUMATIC DESPATGH TUBE APPARATUS.

APPLICATION FILED MAY 31,1904

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PATENTED AUG. 15, 1905.

E. A., FORDYCE. PNEUMATIC DESPATOH TUBE APPARATUS.

APPLIOATION FILED MAY 31,1904.

6 SHEBTS-SHBET 5.

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PATENTED AUG. 15, 1905.

E. A. FORDYGB. PNEUMATIC DESPATGH TUBE APPARATUS.

APPLICATION FILED MAY 31, 1904.

6 SHEETS-SHEET 6.

UNITED STATES PATENT OFFICE.

EDMOND FORDYCE, OF BOSTON, MASSACHUSETTS, ASSIGNOR, BY MESNEASSIGNMENTS, TO LAMSON CONSOLIDATED STORE SERVICE COMPANY, OF NEWARK, NEW JERSEY,A CORPORATION OF NEW-- JERSEY.

PNEUMATIC-DESPATCH-TU BE APPARATUS.

Specification of Letters Patent.

Patented Aug. 15, 1905.

Application filed May 31, 1904.. Serial No. 210,331.

' Tube Apparatus, of which the following is a specification.

My invention relates to new and useful improvements in terminals for pneumatic-despatch-tube apparatus in which a single line is used for the transmission of carriers in both directions and in which pressure is used behind the carriers to drive them from terminal to terminal. a

The main object of myinvention is to economize in the air consumption in pneumatic despatch systems, the air pressure being used only when the carriers are being transmitted through the tube. This and other objects are accomplished by the mechanism shown and hereinafter described. 7

My invention consists of certain novel features hereinafter described, and particularly pointed out in the claims.

In the accompanying drawings, which illustrate a construction. embodying my invention, Figure 1 is a side elevation of the pneumatic-despatch-tube apparatus, partly broken away to show a carrier traveling from the right-hand terminal to the left-hand terminal. Fig. 2 is a longitudinal sectional view through the terminal, with part of the transmissiontube and pressure=tube in full lines, with the parts of both terminals in normal position and no carrier in transit. Fig. 3 is a similar view to Fig. 2, with the left-hand terminal closed and showing a carrier traveling from the lefthand terminal to the right-hand terminal. Fig. 4 is an interior view of the left-hand terminal, showing the interior construction with parts in their normal positions. Fig. 5 is a top plan view of the left-hand terminal with the cover and sliding valve removed to show the interior mechanism. Fig. 6 is an interior view of the left-hand terminal, showing the interior construction, the parts in position immediately after a carrier has been despatched from the left-hand terminal. Fig. 7is a crosssectional view on the line X X, Fig. 6, looking in the direction indicated by the arrow and showing the position of the parts after a carrier has been despatched. Fig. 8 is an untween the two opposite terminals.

der plan view of the slide-valve of each terminal. Fig. 9 is a detail view of the slidevalve with the lever for locking the valve in its closed position. Fig. 10 is adetail view of the mechanism which normally holds the-slidevalve at the right-hand terminal in its open position and is identical with the same mechanism at the right-hand terminal. Figs. 11 and 12 are respectively plan and side views of the lever located in the path of theincoming and outgoing carriers at each terminal. Fig. 13 is a detail view, partly in section, of the elastic circuit controller. Fig. 14 is a diagrammatic view illustrating the circuits be- Fig. 15 is a sectional detail view hereinafter described. Fig. 16 is a plan view of same.

Like characters of reference refer to like parts throughout the several views.

The transmission-tube A for the carriers receives its pressure from the pressure-tube B, connected by the pipe B to any suitable source of air-pressure, and said tube B connects with the transmission-tube A at the right-hand and left-hand terminals D I), respectively, as hereinafter described. The upper ends of the tube A are in alinement with the chutes D D of the terminals D D, respectively, which guide the discharging carriers to a suitable receptacle.

With the parts shown in Figs. 2 and 4 a carrier is inserted for despatch into the lefthand terminal D and passes down into the transmission-tube A and in its travel strikes the lever E, which is connected to the link F by the pin E working in the slot F and moves said lever E downward in the slot A (dotted lines, Fig. 12,) and the motion of this lever E is communicated to the pawl f, which is pivoted at F to the link F and at F* to the piece F secured to the side of the casing. This downward movement of the link F pulls the righthand-end of the pawl f away from the front end of the catch F, pivoted to the slide-valve Gr at F so that the operator taking hold of the handle Cr can move the slide-valve G into its closed position, (shown in Fig. 6,) where it is held closed by the lever G (shown in Fig. 9) against the tension of the springs H which normally tend to open the slide-valve G and hold it in the position shown in Figs. 2 and 4. These springs H are connected to pins H on the under side of the slide-valve G and at the opposite end are secured to a suitable pin in the casing, as shown in Figs. 2, 3, 4L, and 6. The upper end G of. the lever G engages with the recess Gr in the under side of the slide-valve G when the slide-valve G is moved into its closed position, (shown in Fig. 9,) and the spring G normally tends to hold the upper end G in the upper position ready to engage the slide-valve G when the same is closed by the operator for the transmission of a carrier. As shown in Fig. 4, the upper end G of the lever G is in contact with the forward end of the slide-valve G when in its open position.

The spring F, as shown in Figs. 4, 6, 9, and 10, tends to hold the front end of the catch F down, so as to normally engage the righthand end of the pawlf, and when the righthand end of the pawl 7" is pulled down by the link F and away from the catch F the pawl F engages the pawl f and holds the same down under the influence of the spring F", secured around the pin F until the slidevalve G is moved into its closed position, and in the movement of the slide-valve G to its closed position one of the buffers It" on the under side of the rear end of said valve G- rides over the upper end of the pawl F and throws its forward end downward, releasing the pawlf, which moves upward to its normal position under the tension of the spring F" in position to engage the front end of the catch F when the slide-valve G is returned to its normal open position.

Secured to the under side of the slide-valve G are two lugs H, in which is pivoted the finger H, mounted fast on the shaft H and normally held in its vertical position by the spring H secured to the pin H' on the under side of the slide-valve G, (shown in Fig. 8,) and the lower end of said finger H is provided with an antifriction-roller H. This linger H when moved forward is held firmly in its vertical position by the upper square end it engaging the under side of the slide-valve G, so that in the forward movement of the slide-valve G the roller H moves along the top of the lever J, pivoted at K to the casing of the terminal, and depresses said lever from the position shown in Fig. 4 to that shown in Fig. 6 and passes over and beyond the upper curved end of the lever J, as shown in Fig. 6, moving down the rod K pivoted thereto, bringing the contact-point K", mounted on the cross-arm K, into contact with the electric contacts 71? i9, and at the same time this downward movement of the lever J opens the valve K, controlling the flow of air-pressure from the supply-pipe B into the terminal to the transmission-tube A. The lower end of the rod K passes through the guide K and carries on its lower end the valve K. This closing of the electric circuit through the contacts Ink energizes the magnets K K and actfrom the right to the'left hand terminal.

ing on the armature J holds the lever J in its lower position, (shown in Fig. 6,) thereby holding open the valve K until the carrier reaches its destination at the opposite end of the line. The magnets K K being energized draw the armature L to its poles, which in turn throws out into the upper end of the tube A the dogs L, located" in suitable slots at both ends of the line, which prevents a carrier being despatched from the opposite ends of the line while the carrier is in transit toward that end, as an attempt to insert a carrier would bring it into contact with the upper end of the dog L and prevent such insertion. The armature L is mounted on the bracket L by the pins L L Figs. 5 and 7, a slot being provided around the pins L to allow inward and outward movement of the armature L. The armature L at each terminal is pivotally connected by the link If to the dog L, which is'supported on the shaft L and normally held inward by the spring L, connected to said dog, and at its opposite end to the bearing G of the lever G Beyond the collar L of the .dog men the bearing L is a suitable pinfor holding said dog on said bearing. As will hereinafter be shown, when the electric circuit is closed through magnets at one terminal it is closed through the magnets at the other terminal, so that when the armature L at, say, the right-hand station is attracted and throws the dog L out into the upper end of the tube A the same operation takes place at the left-hand terminal, and vice versa, as the armature L being attracted by the magnets at that terminal forces the dog L of that terminal out into the upper end of the tube A at the left-hand terminal into the path of the traveling carrier-moving In respect to the operation of the dogs L* at each end of the line the mechanism is identical and the operation is the same at both terminals, so that when a carrier is despatched from either end to the other the dogs L are thrown out into the upper ends of the transmissiontube Athat is, moving from the inner position (shown in Fig. 4-.) to the outer position (shown in Fig. 6.)

With the slide-valve Gr of the left-hand terminal closed and the parts in the position shown in Figs. 3 and 6 and the pin A between the electric contacts k 70 the current will flow from the battery C through the wire 1, to the binding-post 0, to the magnet K in the lefthand terminal, holding down the armature J, which causes the opening of the valve K Then the current passes through the wire a, through the electric contacts l: 7r, hence through the wire 17 to the binding-post 9, to the wire 8, to the binding-post 7, to the wire 6, through the electric contacts 0 0 and the circuit-controller E then through the wire 5 to the electric contact [6 through the wire 4; to the magnet K, which excites the magnet in the right-hand end of the terminal, so that in both terminals the armature L is drawn to the poles of both magnets, thus throwing out the dogs L in both terminals. Then the current passes through the magnet K to the bindingpost 3, hence to the wire 2, to the battery C.

Now wit-h the parts in the position previously described the carrier A (shown in Fig. 3) is traveling from the left-hand terminal toward the right-hand terminal and upon reaching the right-hand terminal in passing up strikes the lever E in the slot A This lever E is pivotally connected by the pin E to the extended arms E of the rocker-arm E, which is pinned fast on the shaft E by means of the set-screw E and has bearings in the lugs On the outer end of the shaft E* is secured the non-conductive fiber roller E secured fast to the shaft E by the pin E in the inner portion E and in said roller E there is located the metallic strip E, which extends through from side to side. as shown. Normally the metallic strip E bears against the electric contacts a c, mounted on suitable insulating material 0", securely mounted in the base of the terminal. The inner end of the spring E is connected to the roller E and the other extends into one of thelugs E, and

the object of said spring is to keep the rockerarm E in the position shown in fulllines, Fig. 12. Around the pin E is a spring E one end of which extends beyond the rockerarm E and the other extends beyond the lever E, as shown in dotted lines, Fig. 11, and said spring normally holds said lever in the position shown in full lines, Fig. 4, and in the path of the incoming and outgoing carrier. The inner forked ends E of the lever E are squared up on their upper ends, as shown in Fig. 12, so that a carrier inserted strikes the lever E, which swings, as shown in lower dotted lines, Fig. 12, and allows the carrier to continue its travel without ali'ecting the rocker-arm E while an outgoing carrier coming from, say, the left-hand to the right handterminal will strike the lever E and rotate said lever and rocker-arm E in the position shown in upper dotted lines, Fig. 12, because the square end E bears against said rockerarm and causes it to move with the lever E. The rotation of the rocker-arm E causes the rotation of the roller E and said roller is secured fast to the shaft E*, on which the rocker-arm E is also fast. This rotation of the roller E causes the metallic strip E to move from the contacts a e and when the electric circuit is closed causes the same to be broken.

Now the carrier A, previously mentioned, moving from the left to the right hand terminal when it reaches the right-hand terminal will strike the lever E and cause the roller E to rotate (owing to the connections previously described) and break the electric circuit at the contacts 6 e, which will deenergize the magnets K, thus releasing the armatures L, and the dogs If at both terminals will be drawn back into their inner position by the springs L. At the same time the spring M, bearing against the under side of the arm K, and guide M will move the the rod K closing the valve K", and in the upward movement of the rod K the arm J Fig. 5, will strike the lever (i raising .the rear end of said lever upward against the spring G pulling down the front end G from its engagement with the slide-valve G, thereby releasing the valve, which is thrown into its open position by the springs H and as said slide-valve comes to its inner open position the catch F engages the front end ofjthe pawl f, and said slide-valve is thus held securely in its open position ready for the insertion of another carrier into the terminal and cannot be closed until a carrier is inserted into the tube.

The front end (Z of the slide-valve G passes beyond the point (Z of the plate H before the roller H strikes the upper curved portion of the lever J to bring it down into proximity with the magnets K and cause the closing of the electric circuit in the valve K so that the objectionable hissing sound of the air entering the terminal from the supply-pipe B is not heard.

On the lower end of the bracket F is 10- I cated the arm N, with a suitable rubber buffer, against which the lever E in its vertical movement cushions.

The construction and operation of the above terminals are exactly the same. If a carrier is inserted into the right-hand terminal, the course of the electric circuit is as follows: Starting at the battery 0 the current passes through the wire 2 to the binding-post 3, hence to the magnet K, which operates exactly the same as the magnet K previously described for the left-hand terminal, then through the wire at to the electric contacts Z: it, through the wire 16 to the binding-post 15 and wire 14, to the binding-post 13, to the wire 12, to the contacts 6 c,-to the controller E to the contact 0, through the wire 10 to the contact T, through the wire a to the magnet K, which attracts the armature L and throws the dog L* out at the left-hand ter- -minal in the manner previously described.

Hence the current passes to the binding-post c, to the wire 1, to the battery C.

Having thus described the nature of my invention and set forth a construction embodying the same, what I claim as new, and desire to secure by Letters Patent of the United States, is*

1. In a pneumatic-despatch-tube apparatus, acarrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers. a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, and mechanism operated by the closing of said carrierinlet valve for opening said air-inlet valve.

2. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve for opening said air-inlet valve, means for holding said air-inlet valve open, and means at the opposite end of the transmission-tube in the line of travel of the traveling carriers and adapted to be operated thereby to release said air-inlet-holding means to allow said airinlet valve to close.

3. In a pneumatic-despatch-tube apparatus, acarrier-transmission tube havingan inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlr. .t valve for opening said air-inlet valve, means for holding said air-inlet valve open, and means at the opposite end of the transmission-tube for releasing said air-inlet-holding means to allow said air-inlet valve to close upon the discharge of carriers at the opposite end of the line.

4. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrier inlet Valve, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, and mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve.

5. In a pneumaticdespatchtube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrier inlet valve, a source of compressed air, an air-inlet from said source ofcompressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, means for bolding said air-inlet valve open, and means at the opposite end of the transmission-tube in the line of travel of the traveling carriers and adapted to be operated thereby to release said air-inletholding means to allow said air-inlet valve to close.

6. In a pneumatic-despatch-tube apparatus, a earrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrier-inlet valve, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, means for holding said air-inlet valve open, and means at the opposite end of the transmission-tube for releasing said air-inlet-holding means to allow said air-inlet valve to close upon the discharge of carriers at the opposite end of the line.

7. In apneumatic-clespatcl1tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a

vlocking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, and mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve.

8. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a a locking device for normally holding said carrier inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrierinlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, means for holding said airinlet valve open, and means at the opposite end of the transmission-tube in the line of traveling carriers and adapted to be oper: ated thereby to release said air-inlet-holding means to allow said air-inlet valve to close.

9. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmissiontube, a valve controlling said air-inlet, means fornormallyholdingsaid air-inletvalveclosed, mechanism operated by the closing of said carrier-inlet valve after its release for opening said air-inlet valve, means for holding said air-inlet valve open, and means at the opposite end of the transmission-tube for releasing said air-inlet-holding means to allow said air-inlet valve to close upon the discharge of carriers at the opposite end of the line.

10. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inletafter theinsertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve for opening said air-inlet valve, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrier-inlet valve to its normal open position.

11. In a pneumatic-despatch-tube apparatus, acarrier transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube in the line of travel of the traveling carriers and adapted to be operated thereby to release said air-inletholding means to allow said air-inlet valve to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock,

and means for returning said carrier-inlet valve to its normal open position.

12. In a pneumatic-despatch-tube apparatus, acarrier-transmission tubehaving an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, anair-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve for opening said air-inlet valve, means for holding said air-inlet valve open, means atthe opposite end of thetransmission-tube forreleasingsaid air-inlet-holding means to allow said -air-inlet valve to. close upon the discharge of carriers at the opposite end of the line, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrier-inlet valve to its normal open position.

13. In a pneumatic-despatcli-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrier inlet valve, a source of compressed air, an airinlet from said source of compressed air to the transmission-tube, avalve controlling said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrier-inlet valve to its normal open position.

14:. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrierinlet valve, a source of compressed air, an airinlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube in the line of travel of the traveling carriers and adapted to be operated thereby to release said air-inlet-holding means to allow said airinlet valve'to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrier-inlet valve to its normal open position.

15. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrierinlet valve, a source of compressed air, an airinlet "from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube for releasing said air-inlet-holding means to allow said air-inlet valve to close upon the discharge of carriers at the opposite end of the line, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said car rier-inlet valve to its normal open position.

16. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a'source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrierinlet valve to its normal open position.

17. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier t'or operating said-locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve,

means for holding said air-inlet valve open, means at the opposite end of the transmissiontube in the line of the traveling carriers and adapted to be operated thereby to release said air-inlet-holding means to allow said air-inlet valve to close, a lock for holding said carrierinlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said look, and means for returning said carrier-inlet valve to its normal open position.

18. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its release for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube for releasing said air-inlet-holding means to allow said air-inlet valve to close upon the discharge o1 carriers at the opposite end of the line, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrierinlet valve to its normal open position.

19. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube in the line of the traveling carriers and adapted to be operated thereby to release said air-inlet-holding means to allow said airinlet valve to close, a locking-lever for'holding said carrier-inlet valve closed, a spring for holding said locking-lever in engagement with said carrier-inlet valve in its closed position, mechanism operated upon the closing said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier -inlet valve is closed, a source'ot' compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its release foropening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube for releasing said air-inlet-holding means to allow said air-inlet valve to close upon the discharge of carriers at the opposite end of the line, a locking-lever for holding said carrier-inlet valve closed, a spring for holding said locking-lever in engagement With said carrier-inlet valve in its closed position, mechanism operated upon the closing of said airinlet valve for releasing said locking-lever, and springs for returning said carrier-inlet valve in its normal open position.

21. In a pneumatio-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube in the line of travel of the traveling carriers and adapted to be operated thereby to release said air-inlet-holding means to allow said air-inlet valve to close, and a device normally out of the line of travel of the traveling carrier and adapted to be moved into said line of travel to prevent the insertion of a carrier at one. end of the transmission-tube When a carrier is in transit from the opposite end of said transmission-tube.

22. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of.

valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube for releasing said air-inlet-holding means to alloW said air-inlet valve to close upon the discharge of carriers at the opposite end of the line, and a device normally out of the line of travelot' the traveling carrier and adapted to be moved into said line of travel to prevent the insertion of a carrier at one end of the transmission-tube When a carrier is in transit from the opposite end of said transmission-tube. Q

23. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrierinlet valve, a source of compressed air, an air inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmissiontube in the line of travel of the traveling carriers and adapted to be operated thereby to release said air-inlet-holding means to allow said air-inlet valve to close, and a device normally out of the line of travel of the traveling carrier and adapted to be moved into said line of travel to prevent the insertion of a carrier at one end or the transmission-tube when a carrier is in transit from the opposite end of said transmission-tube.

24. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrier-inlet valve, a source of compressed air, an airinlet from said source of compressed air to the transmission -tube, a valve controlling said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said Y release for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube for releasing said air-inlet-holding means to allow said air-inlet valve to close upon the discharge a of carriers at the opposite end of the line, and a device normally out of the line of travel of the traveling carrier and adapted to he moved into said line of travel to prevent the insertion of a carrier at one end of the transmissiontube When a carrier is in transit from the opposite end of said transmission-tube.

25. .I.n a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrierinlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube in the line of the traveling carriers and adapted to be operated thereby to release said air-inlet-holding means to allow said air-inlet valve to close, and a device normally out of the line of travel of the traveling carrier and adapted to be moved into said line of travel to prevent the insertion of a carrier at one end of the transmission-tube when a carrier is in transit from the opposite end of said transmission-tube.

26. In a pneumatic-despa-tcl1-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrierinlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its release for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmission-tube for releasing said air-inlot-holding means to allow said air-inlet valve to close upon the discharge of carriers at the opposite end of the line, and a device normally out of the line of travel of the traveling carrier and adapted to be moved into said line of travel to prevent the insertion of a carrier at one end of the transmission-tube when a carrier is in transit from the opposite end of the trans mission-tube.

27. In a meumatie-despatch-tube appara tus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holdvezosa ing said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed,mechanism operated by the closing of said carrierinlet valve for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmissiontube in the line of travel of the traveling carriers and adapted to be operated thereby to release said air-inlet-holding means to alloW said air-inlet valve to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrier-inlet valve to its normal open position, and a device normally out of the line of travel of the traveling carrier and adapted to be moved into said line of travel to prevent the insertion of acarrier at one end of the transmission-tube when a carrier is in transit from the opposite end of said transmission-tube.

28. In a pneiimatic-despatch-tu'be apparatus, a carrier-transmission tube having an inlot and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normall y holding said air-inlet valve closed,mech anism operated by the closing of said carrierinlet valve for opening said air-inlet valve, means for'holding said air-inlet valve open, means at the opposite end of the transmissiontube for releasing said air-inlet-holding means to allow said air-inlet valve to close upon the discharge of carriers at the opposite end of the line, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrierinlet valve to its normal open position, and a device normally out of the line of travel of the traveling carriers and adapted to be moved into said line of travel to prevent the insertion of a carrier at one end of the transmission-tube When a carrier is in transit from the opposite end of said transmission-tube.

29. In a pneumatic-despateh-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closingof said carrier-inlet valve after its said release for opening said air-inlet valve, means for holding said air-inlet valve open, means at the opposite end of the transmissiontube in the line of the traveling carriers and adaptedto be operated thereby to release said air-inlet-holding means to allow said air-inlet valve to close, a lock for holding said carrierinlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrier-inlet valve to its normal open position, and a device normally out of the line of travel of the traveling carriers and adapted to be moved into said line of travel to prevent the insertion of a carrier at one end of the transmission-tube when a carrier is in transit from the opposite end of said transmission-tube.

'30. In a'pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tn be, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its release for opening said air-inlet valve, means for holdingsaid air-inlet valve open, means at the opposite end of the transmission-tube for releasing said air-inlet-holding means to allow said air-inlet valve to close upon the discharge of carriers at the opposite end of the line, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrier-inlet valve to its normal open position, and a device normally out of the line of travel of the traveling carrier and adapted to be moved into said line of travel to prevent the insertion of a carrier at one end of the transmission-tube when a carrier is in transit from the opposite end of said transmission-tube.

31. In a pneumatic-despatch-tube apparatus, acarrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrier inlet valve, a source of compressed air, an air-inlet from said source of compressed air to the transmissiontube, a valve controlling said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the a closing of said carrier-inlet valve after its said release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrier inlet valve at one end of the transmissiontube to close the circuit, an electromagnet in-' cluded in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, and circuit-breaking means located at the opposite end of the transmission-tube and in the lineof the traveling carriers and adapted to be operated upon the discharge of a carrier to break the electric circuit and release said air-inlet-holding means at the despatch end of the transmission-tube to allow the airinlet valve to close.

32. In a pneumatic-despatch-tube apparatus, acarrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a lockingdevice for normally holding said car- .rier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrierinlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrierinlet valve to hold said air-inlet valve open, and circuit-breaking means located at the opposite end of the transmission-tube and in the lineof traveling carriers and adapted to be operated upon the discharge of a carrier to break said circuit and release said airinletholding means at the despatch end of the transmission-tube to allow the air-inlet valve to close.

33. In a pneumatic-despatch-tube apparatus,a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operatingsaid locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holdingsaid air-inlet valve closedi mechanism operated by the closing of said carrier-inlet valve after its release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrierinlet valve to hold said air-inlet valve open, and circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a'carrier to break said circuit and release said air-inletholding means at the opposite end of the transmission-tube to allow the air-inlet valve to close.

34. In a pneumatic-despatch-tube apparatus,a carrier-transmission tube having an inlet andan outletfor the carriers,a valve forclosing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve for opening said air inlet valve. an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in theline of the traveling carrier and adapted to be operated upon the discharge of a carrier to break said circuit and release said air-inletholding means at the despatch end of the transmission-tube toallow the air-inlet valve to close,,a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrier-inlet valve to its normal open position.

35. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air inlet valve closed, mechanism operated by the closing of said carrier-inlet Valve for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the transmission-tube to allow the air-inlet valve to close, a lock for holding said carrierinlet valve closed, mechanism operated u pon' the closing of said air-inlet valve for releasing saidlock, and means for returning said carrier-inlet valve to its normal open position.

36. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube and having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrier-inlet valve, a source of compressed air, an airinlet from said source of compressed air to the transmission-tube, a valve controlling'said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmissiontube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuit-hreaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a carrier to break said circuit and release said airinlet-holding means at the despatch end of .the transmission-tube to alloW the air-inlet valve to close, a lock for holding said carrierinlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrier-inlet valve to its normal open position.

37. In a pneumatic-despatch-tube apparatus, a carrier-tramsmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrierinlet valve, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to beoperated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energizedupon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a carrier to break said circuit and release said air-inlet-holding means at the despatch end of the transmission-tube to allow the air-inlet valve to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrier-inlet valve to its normal open position.

38. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrierinlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuitbreaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a carrier -to break said circuit and release said air-inlet-holding meansat the despatch end of the transmission-tube to allow the air-inlet valve to close,

-a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of'said air-inlet valve for releasing said lock, and means for returning said carrier-inlet valve to its normal open position.

39. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve,

an electric circuit, circuit closing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said airinlet valve open, circuit-breaking means located at the opposite end of the transmissiontube and in the line of the traveling carriers and adapted to be operated upon the 'discharge of a carrier to break said circuit and release said air-inlet-holding means at the despatch end of the transmission-tube to allow the air-inlet valve to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, and means for returning said carrier-inlet valve to its normal open position.

40. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, asource of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve afterits release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrierinlet valve at one end of the transmissiontube to close the circuit, an electromagnetincluded in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a carrier to break said circuit and release said air-inletholding means at the despatch end of the transmission-tube to allow the air-inlet valve to close, a lock for holding said carrierinlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrierinlet valve to its normal open position, anda device located at each end of the transmissiontube and normally out of the line of the traveling carriers and adapted upon the closing of the electric circuit to move into said line of travel and prevent the insertion of a carrier at the end of the line opposite to that from which the carrier was despatched and to return to its normal position when the circuit is broken.

41. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrier-inlet valve, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, an electric circuit, circuitclosing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a carrier to break the electric circuit and release said air-inlet-holding means at the despatch end of the transmission-tube to allow the air-inlet valve to close,

and a device located at each end of the trans.

mission-tube and normally out of the line of the traveling carriers and adapted upon the closing of the electric circuit to move into said line of'travel and prevent the insertion of a carrier at the end of the line opposite to that from which the carrier was despatched and to return to its normal position when the circuit is broken. a

42. In a pneumatic-despatch-tube apparatus, a earrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier rmoperating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrierinlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, an electric circuit, circuitclosing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit, and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of traveling carriers and adapted to be operated upon the discharge of a carrier to break said circuit and release said air-inlet-holding means at the despatch end of the transmission-tube to allow the air-inlet valve to close, and a device located at each end of the transmission-tube and normally out of the line of the traveling carriers and adapted upon theclosing of the electric circuit to move into said line of travel and prevent the insertion of a carrier at the end of the line opposite to that from which for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its release for opening said air-inlet valve, an 'electric circuit, circuit-closing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a carrier to break said circuit and release said air-inlet-holding means at the opposite end of the transmission-tube to allow the air'inlet valve to close, and a device 10- cated at each end of the transmission-tube and normally out of the line of the traveling carriers and adapted upon the closing of the electric circuit to move into said line of travel and prevent the insertion of a carrier at the end of the line opposite to that from which the carrier Was despatched and to return to its normal position When the circuit is broken.

44. In a pneumatic-despatch-tube apparatus,a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normall y holding said air-inlet valve closed, mechanism operated by the closing of said carrierinlet valve for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmissiontube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, ci rcuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers andadapted to be operated upon the discharge of a carrier to break said circuit and release said air-inletholdingmeans at the despatch end of the transmission-tube to allow the air-inlet valve to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrier-inlet valve to its normal open position, and a device located at each end of the transmissiontube and normally out of the line of the traveling carriers and adapted upon the closing of the electric circuit to move into said line of travel and prevent the insertion of a carrier at the end of the line opposite to that from which the carrier was despatched and to return to its normal position when the circuit is broken.

45. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrierinlet valve for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrierinlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrierinlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a carrier to break said circuit and release said air-inletholding means at the despatch end of the transmission-tube to allow the air-inlet valve to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrierinlet valve to its normal open position, a device located at each end of the transmisiontube and normally out of the line of the traveling carriers and adapted upon the closing of the electric circuit to move into said line of travel and prevent the insertion of a carrier at the end of the line opposite to that from which the carrier was despatched and to return to its normal position when the circuit is broken.

16. In a pneumatic-despatclrtube apparatus, a carrier-transmission tube and having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of thecarriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release, said carrier-inlet valve, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube,a valve controlling said airinlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrierinlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrierinlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a carrier to break said circuit and release said air-inletholding means at the despatch end of the transmission-tube to allow the air-inlet valve to close, a lock for holding said carrier-inlet valve closed, mechanism. operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrierinlet valve to its normal open position, and a device located at each end of the transmissiontube and normally out of the line of traveling carriers and adapted upon the closing of the electric circuit to move into said line of travel and prevent the insertion of a carrier at the end of the line opposite to that from which the carrier was despatched and to return to its normal position when the circuit is broken.

47. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open and operated by an inserted carrier to release said carrierinlet valve, a source of compressed air, an air inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said airinlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrierinlet valve at one end of the transmission-tube to close the circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted l said locking device to release said carrier-inlet to be operated upon the discharge of a carrier to break said circuit and release said air-inletholding means at the despatch end of the transmissiontube to allow the air-inlet valve to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrier-inlet valve to its normal open position, and a device located at each end of the transmission-tube and normally out of the line of the traveling carriers and adapted upon the closing of the electric circuit to move into said line of travel and prevent the insertion of a carrier at the end of the line opposite to that from which the carrier was despatched and to return to its normal position When the circuit is broken.

18. In a pneumatic-despatch-tube appara tus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said'carrierinlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet Valve, means for holding said locking device in its released position until the carrierinlet valve is closed, a source of compressed air, an air-inleti'rom said source of compressed air to the transmission-tube, a valve controlling said air-inlet, an electric circuit, circuitclosing means adapted to be operated upon the closing of the carrier-inlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrier-inlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers to break said circuit and release said air-inlet-holding means at the despatch end of the transmission-tube to allow the airinlet valve'to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrier-inlet valve to its normal open position, and a device located at each end of the transmission-tube and normally out of the line of traveling carriers and adapted upon the closing of the electric circuit to move into said line of travel and prevent the insertion of a carrier at the end of the line opposite to that from which the carrier Was despatched and to return to its normal position when the circuit is broken.

49. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally'holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating valve, means for holding said locking device in its released position until the carrier-inlet valve-is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its said release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrierinlet valve at one end of the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrierinlet valve to hold said air-inlet valve open, circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be operated upon the discharge of a carrier to break said circuit and release said air-inletholding means at the despatch end of the transmission-tube to allow the air-inlet valve to close, a lock for holding said carrier-inlet valve closed, mechanism operated upon the closing of said air-inlet valve for releasing said lock, means for returning said carrierinlet valve to its normal open position, and a device located at each end of the transmissiontube and normally out of the line of the traveling carriers and adapted upon the closing of the electric circuit to move into said line of travel and prevent the insertion of a carrier at the end of the line opposite to that from which the carrier Was despatched and to return to its normal position When the circuit is broken.

50. In a pneumatic-despatch-tube apparatus, a carrier-transmission tube having an inlet and an outlet for the carriers, a valve for closing said inlet after the insertion of the carriers, a locking device for normally holding said carrier-inlet valve open, mechanism operated by an inserted carrier for operating said locking device to release said carrier-inlet valve, means for holding said locking device in its released position until the carrier-inlet valve is closed, a source of compressed air, an air-inlet from said source of compressed air to the transmission-tube, a valve controlling said air-inlet, means for normally holding said air-inlet valve closed, mechanism operated by the closing of said carrier-inlet valve after its release for opening said air-inlet valve, an electric circuit, circuit-closing means adapted to be operated upon the closing of the carrierinlet valve at one endof the transmission-tube to close the circuit, an electromagnet included in said circuit and energized upon the closing of said circuit by the closing of the carrier- ,inlet valve to hold said air-inlet valve open,

circuit-breaking means located at the opposite end of the transmission-tube and in the line of the traveling carriers and adapted to be oper-

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