US574965A - watson - Google Patents

Description

(No Model.) 3 Sheets-Sheet 1 J. A. WATSON.

. VACUUM DBSPATGH SYSTEM. No. 574.965. Patented Jan. 12,1897.

3 Sheets-Sheet 2.

(no Moder.

J A. WATSON. VACUUM DESPATGH SYSTEM.

No. 574,965; Patented Jan. 12, I897.

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UNITED STATES PATENT OFFICE.

JAMES A. WATSON, OF IVASHINGTON, DISTRICT OF COLUMBIA.

VACUUM DESPATCH SYSTEM.

SPECIFICATION forming part of Letters Patent No. 574,965, dated January 12, 1897.

Application filed February 18, 1893. Serial No. 462,901. (No model.)

To all whom it may concern.-

Be' it known that I, JAMES A. WATSON, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Vacuum Despatch Systems, of which the following is a specification.

This invention is denominated a vacuum despatch system.

The object of the invention is to provide means for the carriage of mail and express matter and light freight at a high rate of speed and with a minimum expenditure of power.

In the apparatus of the invention there is a tube which is closed at the ends by suitable valves or gates and one or more air-exhaust pumps (arranged at regular intervals along the tube, when it is a long one) for exhausting the air from all portions of the tube and maintaining within it a vacuum as nearly perfect as is possible. At the initial end of the tube there is a lock-chamber, by means of which cars or carriers may be inserted in the tube without permitting the atmospheric air to enter. Means are provided for pro pelling the carriers within the tube, the preferred means being electricity, and the preferred arrangement being to place the dynamos in the pumping-stations, so that they may be operated from the same source of power as the pumps.

The invention further consists of the details of the lock-chambers and the means for receiving and stopping the carriers at their destinations.

The term tube is used in this specification in a sense broad enough to include any hollow trunk, whether square, round, or of any other section. The term vacuum will be understood to include the attenuated or rarefied atmospheres attainable with mechanical air-pumps, and the term carrier, as used, will include any cars or conveyances adapted to travel within a tube.

I may propel the carriers within the vacuum-tubes by any suitable means, such as a cable, but I prefer electricity, and in the accompanying drawings I have illustrated two ways of propelling them by this form of force.

Rapid transit for mail and express matter has been heretofore accomplished in one or the otherof two methods. One of these methods is to provide a railway with rails so placed as to prevent the car from leaving them, and then to provide powerful motors, usually electrical, to force the cars forward at the highest practicable speed. \Vith this method a very high rate of speed cannot be attained for the reason that the resistance of the air to the movement of the car increases nearly as the square of the speed of the car and becomes enormous for high speeds, thus rendering it costly to maintain a moderatelyhigh speed and impossible to obtain as high a speed as is desirable. The pneumatic-despatch tube is the other means of propelling cars or carriers at a high rate of speed, but such tubes are not practicable for the highest speeds or for long distances. The reason for this is that a column of air the length of the tube has to be propelled, as well as the carriers within the tube. This air is propelled either by forcing it in at one end of the tube or exhausting it from the other end, or both. In either case the friction of the air upon the tube is very great and consumes a large portion of the power.

Referring to the drawings, in which like parts are indicated by similar reference-signs throughout the several views, Figure l is a diagram of a tube with the operating devices therefor, parts of the tube being broken away. Fig. 2 is an enlarged longitudinal section showing a portion of the tube and a carrier. Fig. 3 is a cross-section on the line 3 3 of Fig. 2. Fig. 4 is a sectional View similar to Fig. 3, showing a tube provided with a double track. Fig. 5 shows a diagrammatic view of a tube provided with different means of propulsion, and Fig. 6 is a sectional view of a tube without internal rails and showing an end elevation of a carrier adapted to run in such a tube.

In the drawings, A A indicate tubes, B 13 indicate the air-pumps for exhausting the air from the tubes, and O 0 indicate dynamos for supplying motive power to propel the carriers. I prefer to arrange the power-stations at regular intervals along the line of the tube and to place an air-pump in each power-station. These pumps may be operated continuously or periodically, depending upon the amount of leakage of air into the tubes.

tube.

With perfectly air-tight tubes very little pumping will be necessary.

In Figs. 1 and 5, A indicates the initial or starting end of the tube. This end, as shown, is provided with two valves, one at either end of a lock-chamber, which permits the carrier D to be trapped into the tube without permitting the entrance of any but a small portion of air. As shown, there is a valve 1 at the end of the tube which is pivoted at 2 and provided with an operating-handle At a distance slightly greater than the length of the carrier from the end of the tube is a second valve 4:, which may be drawn up into a casing 5 by means of a hand-wheel 6, attached to the screw-stem of the valve. Extending around the valve 4 is a by-pass pipe 7, provided with a valve 8, said pipe forming a communication between the lock-chamber and the vacuum-tube. Another pipe or port 9, controlled bya valve 10, forms a communication between the loclcchamber and the atmosphere.

In Figs. 1 and 5, A indicates the delivery end of a single-track tube. As illustrated, the end of the vacuum-tube is closed by a pair of pivoted gates 11, which are arranged to open automatically upon the arrival of a carrier. The gates 11 are each provided with toothed quadrants 12, which are operated by racks 13, attached to the armature 11 of a powerful electromagnet 15. Springs 16 are provided for closing the gates, and they are held tightly closed normally by the atmospheric pressure. The circuit through the magnet is completed by the carrier, as it passes between terminals 17 before reaching the gates, the gates are in'nnediately opened, and the carrier passes out into an open tube 1!), which forms an air'cushion. The tube 19 may be of any suitable length, according to the speed at which carriers arrive. Its outer end is closed by a valve 20, and it is also preferably provided with a whistle 21 and a vent 22.

The operation of starting and stoppin g the carriers is performed as follows: Referring to Fig. 1, the valves 1 and S are closed and the valve 10 opened to admit air into the lockchamber and relieve the external pressure on the valve 1. The valve 1 is then opened and the carrier D passed into the lock-chamber. The valves 1 and 10 are then closed. The carrier will have displaced most of the air in the lock-chamber, and the remaining air may be pumped out directly or permitted to pass through the valve 1 when it is opened. In order to relieve the great pressure on the valve 1 before opening it, if the air has not been pumped out of the lock-chamber, the valve 8 in the bypass 7 may be opened, thus permitting the air to go into the vacuum- The carrier may then be started into the tube. \Vhen arriving at the other end of the tube, the carrier strikes the contacts 17, and the gates 11 are immediately opened by The carrier, traveling at a the magnet 15.

high velocity, passes through the gates 11 into the tube 19 and is gradually stopped by the resistance of the air in the tube. The gates 11 are immediately closed by the springs 16. The compression of the air will sound the whistle 21 and notify the attendant, so that the valve 20 may be opened. The air-veut 22 should be large enough to prevent the carrier from compressing the air to such an ex tent as to cause it to rebound. Byinclining the tube 19 the carrier will run bygravity to the exit-valve 20. Y

In Figs. 1, 2, and 3the carrier is propelled by means of an electric motor 23, the current coming from the dynamos C and passing through the insulated rail M, the trolley wheel 25, the motor, the driving-wheel 26, and returning through the rail 27 or the tube itself. The motor, as shown, is connected to the driving-wheel by means of a belt 28 and pulley 29. In Fig. 5 the motive power is supplied through a series of solenoids 80, which are brought into action successively by the carrier itself, which closes the circuits between the contacts 31 and 32. The above methods of propelling carriers need not be more particularly described, as they are common and well known to those skilled in electricity. Many other ways of propelling carriers in vacuu1n-tubes will suggest themselves. For distances of a few miles it may be desirable to operate the carriers by gravity. This may be easily accomplished by running the starting end of the tube to the upper lloor of a high building or into a tower. A fall of two hundred and .iifty feet will give the carrier an initial velocity of about two miles per minute, and this velocity will carry it a long distance through the tube, as the resistance is very slight. In this way short lines of despatch-tubes in cities may be economically operated.

One advantage of myim proved system over pneumatic tubes is that carriers may be run in opposite directions in the same tube. For this reason alarge tube may be erected, which will admit a workman for the purpose of making repairs at about the same cost which it would take to construct two smaller tubes. A cross-section of such a tube is shown in Fig. 4. Another advantage is that tubes intended for the passage of single carriers may be formed with a perfectly smooth interior, leaving nothing to get out of order. Fig. 6 shows a cross-section of such a tube with an end view of a carrier adapted to run in it. These carriers are provided with three or more wheels at each end, so that it does not matter which side of them is uppermost.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s-

1. In a despatch system, the combination of a normally closed and exhausted tube, a carrier movable within the tube, and exhausting mechanism to constantly maintain a vac uum within the tube.

2. In a despatch system, the combination of a normally closed and exhausted tube, a carrier movable within the tube, and means for propelling the carrier within the tube.

3. In a despatch system, the combination of a normally closed and exhausted tube, a carrier movable within said tube, a motor upon the carrier, and means for supplying power to the motor.

4. In a despatch system, the combination with a normally closed and exhausted tube, and exhausting mechanism to constantly maintain a vacuum therein, of a lock-chamber having suitable valves to seal the main tube against the inflow of air while a carrier is being introduced.

5. In a despatch system, the combination ofanormally-exhausteddespatch-tube,means for maintaining the tube in an exhausted condition, a carrier movable within the tube, suitable valves through which the carrier may be passed into and out of the tube, and means for propelling the carrier within the tube.

6. In a despatch system the combination with a normally closed and exhausted tube and a carrier movable therein, of a lockchamber at the initial end thereof adapted to be closed air-tight, a valve for controlling communication between the lock-chamber and the tube proper, a second valve for controlling communication between the lockchamber and the atmosphere, said lock-chamber being preferably but little larger than said carrier, whereby the carrier may be introduced into the tube Without impairing the vacuum in the latter, substantially as described.

7. In a despatch system, the combination with a normally-closed and exhausted tube and a carrier movable therein, of a lock-chamber separated from the exhausted portion by a valve, an entrance-valve at the outer end of the lock-chamber, and means for alternately filling the lock-chamber with air and exhausting the same, to facilitate the opera tion of the valves, substantially as described.

8. In a despatch system, the combination with a normally-closed and exhausted tube, of

a lock-chamber separated from the exhausted portion of the tube by a valve, a valved bypass pipe around the said valve, an entrancevalve at the outer end of the lock-chamber, and a valved port communicating between the lock-chamber and the atmosphere, substantially as described.

9. In a despatch system, the combination of a normally-closed and exhausted tube, a carrier movable therein, and a tube 19 having its outer end normally closed and its inner end open to the atmosphere and in line with the exhausted tube, said tube 19 being arranged to receive the carrier from the exhausted tube and form an air-cushion for the same, substantially as described.

10. In a despatch system the combination of a normally-closed and exhausted tube having two or more separate tracks or guideways therein, carriers movable within the tube and adapted to said tracks, and means for propelling said carriers in opposite directions at the same time, substantially as described.

11. In a despatch system,the combination of a normally-closed and exhausted tube, a carrier movable within said tube, and a series of exhaust-pu mps in communication with said tube, said pumps being arranged at intervals along the line of the tube, whereby any air due to leakage may be removed without creating detrimental air-currents, substantially as described.

12. In a despatch system, the combination ofv a normally-closed and exhausted tube, carriers movable within said tube, electromotors for operating the carriers, and a series of power-stations arranged at intervals along the tube, each station being provided with dynamo-electric machinery and air-exhaust pumps connected with the tube for supplying power to the carriers and exhausting the air from said tube respectively, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

7 JAMES A. WATSON.

Witnesses:

WILL E. NEFF, W. CLARENCE DUVALL.

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