US800275A - Pneumatic-despatching-tube system. - Google Patents

Description

No. 800,275. .PATENTBD SEPT. 26, 1905'.

I W. H. DINSPEL & J. J. STOETZEL.

PNEUMATIC DESPATCHING TUBE SYSTEM. a

APPLICATION FILED JUNE 17 1904 7 SHEETS-SHEET 1.

& E II 'NO- 800,275. PATENTED .SEPT. 26, 1905.

' W. H. DINSPEL & J. J. STOETZEL.

PNEUMATIC DESPATCHING TUBE SYSTEM.

APPLIOATIONVIILEDI JUNE 17, 1904.

7 SHEETS-SHEET, 3.

No. 800,275. PATENTED SEPT. 20, 1905.

W. H. DINSPBL & J. J. STOETZEL. PNEUMATIC DESPATGHING TUBE SYSTEM.

APPLICATION FILED JUNE 17, 1904.

7 SHEETS-SHEET 4.

Np. 800,275. PAlTENTED SEPT. 20. 1905.

W. H. DINSPEL & J. J. STOBTZEL.

PNEUMATIC DESPATGHING TUBE SYSTEM.

APPLIOATION FILED JUNE 17, 1904.

Y 7 SHEETS-SHEET 5 N n\\\ \\\E S Ir DREW I nu l4 c0 mom-mm! Kits. '1 SH MIT PATENTED- SEPT. 26, 1905. W. H. DINSPEL, & .T. J.. STOETZEL. BNEUMATIG DBSPATGHING TUBE SYSTEM:

APPLIUATIONI FILED mm; 11, 1904.

7 suns-sum e.

PATBNTED SEPT. 26,, 1905. z W.- H."DINSPEL & J. I. STOBTZEL. PNEUMATIC DESPATGHING TUBE SYSTEM.

7 SHEETS-SHEET 7.

I UNITED 'sT TEs' PATENT, onion. 7 v

WILLIAM H. DINSPEL ANnJosErr'i J. STOETZEL, or ornoAeo, ILLINOIS. PNEUMATICeDESPATCH INC-I TUBE SYSTEM.

"Spec ification of Letters Patent.

Patented Sept. 26, 1905.

Application filed June 17, 1904. Serial No. 212,931.

To all whom it may concern.-

Be it known that we, WILLIAM H. DINSPEL and J OSEPH J. SToETznL, vcitlzens of the United States of America, and residentsof phicago, in the countyzof Cook and State of Illinois, have invented certain new and useful Improvements in Pneumatic-Despatching- Tube Systems, of which the following is a specification; M

The main objects of this invention are to provide animproved form of pneumatic-dc spatch-tube system which is economical. in structure and operation and suitable for either long or short distance transmission; to provide improved means for supplying power in.

a long-distance pneumatic transmission system at a plurality of relay-stations along the line, thereby greatly reducing the frictional resistance of the air passing through the system and making it possible to operate such systems with less powerful machinery and smaller running expenses, to provide 1mdespatching mechanism, the supporting-frame Z proved means for automatically operating valves at the despatch end of the tube and at the various relays, so as to'allow carrier-car tridges to be sent through the system in close sucoessionand at the same time prevent the possibility of a plurality-of such cartridges becoming bunched at one point of the system and requiring great expenditure of power to move same, and to provide in a system of this class improved automatic mechanicallyoperated means for setting the relay-valves through the action of the passing cartridge;

and without resorting to electrical connections which require attention to prevent ineflioiency through corrosion-of connections, &c. We accomplish these objects by the device shown in the accompanying drawings, in which- Figure 1 is a diagrammatic View of a pneumatic transmission system constructed ac- Fig. 2 is a longifor some of the parts being omitted for the sake 'of-clearness, Fig. 3 isa longitudinal section of one of the suction-valves on the line 3 3 of Fig, 4. Fig. 4. isa transverse section of the same on the line 4 4 of Figs, 3 and 5. Fig. 5 is a top plan, partly broken away,

of the suction valve operating mechanism, the full lines showing the position of the parts corresponding with the open position of the valve. Fig. 6isalongitudinal section, partly broken away, of the relay mechanism. Fig.

tions.

the suction-pipe and adapted to maintain a vacuum in advance of a cartridge passing along the tube, air-valves for admitting air behind the cartridge at suitable intervalsalong the line, mechanism for automatically operating the suction and air valves so as to carry a cartridgethrough the system, together with a governing device actuated by the vacuum in the system and controlling the operation of the pumping mechanism.

- In the construction shown the suction-pipe 1 extends throughout the entire system and has ateach side of same and parallel therewith a transmission-tube 2, said tubes being adapted to carry cartridges in opposite direc- Air is exhausted from the suctionpipe 1 by means of a-prirnary pump 3 and an auxiliary pump 4, both of said pumps being driven byxthe motor 5. The transmissiontubes are provided with valves which are normally closed to prevent air from entering such tubes, and the tubes are connected with the suction-pipe by air-passages at their terminals and at a plurality of relay-stations, one of which is shown on each pipe in Fig. 1. The pump 4 is adapted to maintain a vacuum of a certain number of inches when the transmission-tubes are not in service, said pump being regulated to neutralize the leakage of air into the system. The pump 3 is of suificient capacity to maintain the desired intensity of vacuum. It will be seen that the pump 3 need therefore be operated only when the transmission-tubes are in service, and a gov- .ernor 6, actuated by the vacuum in the system, is provided for controlling the operation of said primary pump. The-pump L is driven directly from a belt 7, connected with the engine 5, while the primary pump 3 is driven by the belt 8 from the engine 5, with thegovserning mechanism 6 intervening. The belt8 drives a loose pulley 9, journal'ed on theshaft 10, which connects with the pump The friction-clutch of the governing mech-- 'anism consists of an annular flange 1 1,'which v is rigid on the loose pulley 9,'and hub 12,

keyed to the shaft 10 within the flange 11 and adapted to have frictional contact with the flange 11 through an annular shoe 13, which is seated in an annular groove in the periphery of the hub 12 and is normally out of engagement with the flange 11. A spirally-coiled pipe 1 1 separates the shoe 13 from the hub 12 and is adapted to expand under pressure and force the shoe 13 into frictional contact with the flange 11, thus causing the shaft 10 to be driven through rotation of the pulley 9. end of the flexible pipe 1 1 is closed, while the other end connects with a fitting 15, disposed axially of the shaft 10 and revoluble'therewith and having swiveled water-tight connection at 16 with a pipe 17. The pipe 17 communicates With the interior of a cylindrical tube 18, within which are slidably mounted the piston-valves 19 and 20, which are rigidly connected with each other and suitably arranged so that their movement along the tube 18 will connect the pipe 17 either with the inlet-pipe 21 or with an exhaust-pipe 22. The pipe 21 communicates with a suitable reservoir, (not shown,) from which water is supplied under sufficient pressure to expand the tube 14 of the clutch. When the pistons are in the position shown in Fig. 8, the pipe 14: is connected with the pipe 21 and water is admitted to the pipe 14, which expands and causes the pump 3 to be operated. i/Vhen the pistons move toward the left, the piston 19 cuts off the connection between the pipes 17 and 21 and permits of communication between the pipes 17 and 22, permitting the escape of the fluid from the tube 14: and causing same to contract and permit the shoe 13 to move out of frictional engagement with the flange 11, thereby stopping the pump 3.

Movement of the pistons 19 and is controlled by means of a diaphragm 23, which is connected to said valves by the rod 2 1. The diaphragm 23 is inclosed within a chamber 25. The right-hand side of the diaphragm is exposed to atmospheric pressure through the perforations 26 in the walls of the chamber 25, while the otherside of the diaphragm communicating through a suitable fitting 27, with the pipe 28, which connects with the suction-pipe 1. The rod 24 extends through the diaphragm 23 and is seated in a bearing member 29, which is threaded into the fitting 27 and adjustable longitudinally of the rod 24:. A spiral spring 30 surrounds the rod 24: and bears between the diaphragm 23 and the inner end of the member 29, normally urging the parts into the positions shown by the full lines in the drawings. When the pressure within the suction-pipe falls, the air-pressure on the diaphragm 23 causes same to move toward the left, thereby opening communication between the pipes 17 and 22, permitting the escape of liquid from the tube 14:, and consequently stopping the pump 3. The tension One of the spring 30 is regulated to suit any desired vacuum-pressure by adjusting the member 29. To prevent slight fluctuations of the vacuum in the suction-pipe from atl'ecting the clutch and to hold the parts at their limit of other movements, a weighted lever 31 is pivoted to the tube 18, connected with the rod 24. The weight on the lever is adjustable and tends to resist the movement of the valves until the lever passes its vertical position, when said weight will assist in throwing the valves to the other limit of their movement.

The despatehing mechanism comprises a. receptacle 32, having a hinged cover 33, communicating with the receiving end of the tube 2 through a valved despatch-box 31-, together with suitable pneumatic mechanism for operating the valves of the despatch-box. 'lhe receptacle 32 and its cover 33 are adapted to entirely inclose a cartridge for carrying articles through the tube and are provided with apertures 35, having a combined area small compared to the area of the despatchtube 2. The despatch-box is provided with two valves extending across the path of the cartridge, the valve 36 being a sliding gatevalve, while the valve 37 is a swinging valve pivoted at 38, opening inwardly of the despatch-tube and normally braced in its closed position by means of a toggle-link strut 31). The despateh-box is further provided with an air-valve 4:0, pivoted at 11, opening to the outer air and located inward of the tube from the gate 36. The gate 36 is operated by a stem 12, which is moved bymeans of a piston in the cylinder 43. The opposite ends of the cylinder 43 are connected, by means ol the pipes 1 1 and 4:5, with an air-inlet 16 and are controlled by a three-way valve -17, operated by the handle 418 to admit air to either end of the cylinder, as desired. The ends of the cylinder are also connected in similar manner to a pipe &9, connected with the suctionpipe and controlled by the three-way valve 50. The valves 17 and are each provided with an arm 51, connected by a link 52, as shown, so that when one end of the cylinder 43 is connected with the vacuum-pipe the other end will be exposed to atmospheric pressure. Asecond link 53 connects the link 52 with a bell-crank lever A second cylinder 55 is located near the cylinder 13 and has a piston-rod 56, arranged to open the valves 40 and 37. The member 57, at the lower end of the rod 56, is connected with the valve 40 by means of a link 58, which has a slot at 59 at its upper end to permit a considerable upward movement of the stem 56 before the valve 40 is opened. The togglestrut 39 is shown in its limiting position as controlled by the lug 60 on the link 61. The

arm 62 is rigid on the shaft 63, which connects, by means of a second arm 61 and link 65 outside of the tube, with a trip-arm 66, having a weighted pawl 67 pivoted at its end.

The pawl 67 engages the member 57 in such manner that an upward movement of the pi'ston-rod 56 will raise'th'e arm 66 until the rotation of such arm permits the pawl to slip off the end of the member 57. When the member 57 moves downward, the pawl 67 swings away to permit the member 57 to pass below same. The upward movement of the main suction-pipe 1. The two ends of the cylinder 55 are further connected by means of a by-pass 72, controlled by a valve 73, through which the pressures on the opposite sides of the piston within the cylinder 55Ttend to equalize each other when the valve'69 is in its closed position, as shown in the drawings.

The valve 73 -controls the equalization of pressures, and thereby times the descent of the piston in the cylinder 55. The by-pass .72 is considerably smaller than the air-inlet 68,

and therefore does not affect the movement of the piston when the air-inlet 68 isopened. The movement of the valve 69 is controlled by the cylinder 13 through engagement of part of the relay-fitting, and its weight is counterbalanced by means of a spiral'spring 77, so that the gate is held normally open and is very sensitive and requires little force to close it. The tube communicates with the outer air at each relay-station through a valve 78, located beyond the gate 75 in the direction of the movement of a cartridge passing along the tube, and a suction-valve 79 conmeets the transmission-tubewith the suctionpipe in front of the valve 75. The suctionvalve 79 is located a considerable distance from the gate 75 in order that if the gate happens to be closed the rare air in front of the cartridge during its passage between the suction-valve 79 and the gate 75 will be compressed sufliciently tocause the gate 75 to commence to open before being struck by the cartridge.- The face of the gate 75 is curved, as shown, so that a cartridge striking same would tend to wedge the gate open rather than striking a direct blow upon same. The suction-valve 79 is normally open, butis closed through the engagement of a passlng.

so that the difference in pressures between not affect the, sensitiveness'of the valve.

Within the valve-casing 81 are two cylindrical valve-seats 82, which communicate,-

. through, the apertures 83, with annular passages'8 1, connected with the suction-pipe -1.

'The valve-plates 85 are cylindrical and pro- 'vided with apertures corresponding with the apertures 83 of, the valve-seats. The ends of the cylindrical valve-plates 85 are open and communicate with a passage 86, connected with the interior of the tube 2. The valveplates thuscohtrol the connection between the tube 2 and the suction-pipe 1 and are opened and closed by being rocked on their shaft 87. An arm 88 is rigid on the shaft 87 and extends into sliding engagement with a cam-slot 89in the cross-head 90, which is slidably mounted in suitable guides in the valve-casing. It will be seen from the drawings that a movement of the cross-head 90 along the valve-casing will cause the arm 88 to rotate the valve-plate 85. Movement of the cross-head 90 is effected by means of a rod 91, to which is connected a lever 92, fulcrumed at 93 on the tube 2. The cross-head 90 is normally urged in directidn for moving the valve-plates 85 into their closed position through the action of the spring 94, which is normally under tension and has its ends secured, respectively, to the link 96 and a'fixed bracket 95. The'link 96, which ispivoted to the lever 9,2, passes' through a guide-aperture the arm or detent 97, which is rigidly connected with the trip-lever 80, and thus hold the valve in its open position. The arm 97 is adapted to be moved out of engagement with the link 96 through the contact of the cartridge with the trip-lever 80, permitting the spring 945 to close the valve. The trip 80 is seated in ahousing 98, so that it may move entirely out of the path of the cartridge.

The valve 78 is opened by means of a rod 99, connected with the piston 100 in the cylinder 101. The cylinder 101 is provided with an air-inlet 124,, a suction connection 122, and a byl-pass 123, arranged in a similar manner as the corresponding parts of the cylinder 55. The air-inlet 124 is controlled by a valve 102 on a bell-crank lever 103, which eonnectswith a second bell-crank lever 104 by means of a link 105. The bell-crank lever 10 1 is loosely connected,,by means of a rod 106, with a trip 107,.which is mounted in a housing 108 above the tube 2 and extends ,into said tube, so as to be engaged by a passing cartridge.

When the trip 107 is lifted by the cartridge, it causes the .valve 102 to open, and-thereby causes an upward movement of the piston 100'and opens the airvalve 78. As the piston-rod 99ffa'scends the lug 109 engages the bell cranklever 102 and again closes the inlet 124, whereupon the'air in the cylinder 101 below the piston 100 gradually escapes through the by-pass 123. This permits the Weight of the piston to cause the same to gradually descend and close the valve 78. The rod 99, through engagement with the bell-crank lever 110, which is represented by dotted lines in Fig. 6 and which is connected with the rod 91, is thus also adapted to set the valve 79 in its open position when the piston 100 ascends. This connection is also shown diagrammatically in Fig. 1.

' The terminal of the despatch-tube 2 is fitted with a flap-valve 111, opening outwardly and pivoted at 112 in a suitable hood 113, and is connected by a pipe lit with the suctionpipe 1. The area of the pipe 114 is considerably less than that of the despatch-tube 2 in order that while the pipe 114: will normally maintain avacuum in the last section of the despatch-tube 2 a cartridge rapidly approaching the valve 111 will compress the air in advance of same more rapidly than air is being exhausted by the pipe 114 and will thereby cause the valve 111 to start to rise before beingengaged by the cartridge. The valve 111 is preferably partly balanced by a spring 115, so as to offset the inertia of the parts of such valve, as was the case of the relay-valve 75. The tube 2 discharges upon a table 116, which is shown broken away in Fig. 7. At the opposite side of the table 116 and opposed to the tube 2 is a dash-pot 117, adapted to stop the advance of. the cartridge and discharge same upon the table 116, which may be slightly inclined toward one side, so as to cause the cartridge to roll into a suitable receptacle. (Not shown.) The dash-pot 117 comprises a cylindrical casing 118, flared at the end opposed to the tube 2 and closed at its other end except for the usual air-escape aperture or apertures 119. A piston 120 is slidably mounted within the casing and is normally urged toward the open end of same by means-of a spring 121. It is preferred to provide means for regulating the area of the air-escape apertures 119, as shown.

The operation of the system shown is as follows: As hereinbefore explained, it will be understood that the pump 4 is arranged to maintain the vacuum within the system against the ordinary leakage of air through the valves and joints of same when the system is not in use, while the pump 3, through the action of the governor 6, operates only when the admission of air to the system for the purpose of driving cartridges through same requires such extra pumping power for the purpose of maintaining the vacuum at the desired intensity. To send a cartridge through the system, the cover 33 of the receptacle 32 is thrown open, a cartridge is placed in such receptacle, and the cover closed. The lever 48 is then turned downward, as shown by the arrow in Fig. 2, admitting air to the cylinder 4C3 below the piston therein, connecting the upper end of the cylinder with the suctionpipe by means of the three-way valves, as hereinbefore described, and causing the gate 36 to open. As the gate 36 opens the lug 74 on the rod 42 engages the lever 70, and thus causes the admission of air to the air-inlet 68 of the cylinder 55. This causes the member 57 to rise, causing the collapse of the joint of the toggle-strut 39 and permitting the opening of the gate 37. The cartridge is now forced into the despatching-tube 2 by the pressure of air behind same. Such movement is at first gradual on account of the limited amount of air admitted by the contracted apertures 35. Continued upward movement of the member 57 lifts the air-valve 10 and admits larger quantities of air behind the cartridge, while the arm 57 becomes released from the member 57 and permits the closing of the valve 37, followed by the closing of the valve 36 through the reversal of the three-way valves 17 and 50, which is caused by the lifting of the bell-crank lever 51 by the member 57. The valve 69 is simultaneously raised by the member 57 to close the air-inlet 68 in the cylinder 55. Leakage of air through the by-pass valve 73 now causes an equalization of pressures in opposite ends of the cylinder 55 and allows the member 57 to descend under the action of gravity and gradually close the valve 10. The member 57 also passes below the pawl 67 on the lever 66 and into position for lifting such lever previous to the passage of another cartridge. Through adjustment of the by-pass valve 73 the closing of the valve 40 is regulated so that the valve will remain open sufficiently long to cause the cartridge to be carried beyond the first relay-gate. As the cartridge passes the suction-valve 79 in its approach to a relay-station it engages the lever 80, tripping said lever and permitting the valve to close. The air-pressure behind the cartridge,together with the momentum of such cartridge, causes same to continue along the tube and if the valve 75 is closed compressing the air in advance of same and finally lifting the gate 75 at the relay-station. The cartridge continues its movement under the suction in the succeeding section of the tube and lifts the lever 107, opening the valve 102 and causing the piston 100 to open the air-valve 78. The air rushing in through the valve 78 insures the closing of the gate 75 and supplies new impelling force to the advancing cartridge. The rise of the piston 100 also operates the bell-crank lever 110 and reopens the suction-valve 79. The lever 80 falls back into position for engaging another cartridge and locks the suction-valve in its open position. It will be understood that after the closing of the gate 75 and the opening of the suction-valve 7 9 the vacuum in the first seetion of the pipe is almost instantly established and the tube is inreadiness for thetransmis-. 'sion of other cartridges, the gate 75 remain ing closed until after the valve 78 is closed and the pressures on both sections of the tube cartridge through the gate 111 said gate closes behind the cartridge and the vacuum is again established in the last section of the tube by the pipe 114. The compressionof air in advance of the cartridge necessary for cartridge is overcome in the dash-pot 117,-

opening the valve 111 againstatmospheric pressure has the effect of gradually reducing thespeed of the cartridge previous to its delivery. Any remaining momentum of the after which the cartridge is delivered upon the table 116.

It will be seen that the relay mechanism herein shown is suitable for supplying-the power from aplurality of pumping-stations located at intervals along the line, thus avoidnnit a cartridge along same; a gate extending ing the enormous losses in friction which occur when air must be pumped through long lengths of piping.

Itwill be seen that numerous details of the construction shown may be altered without departing from the spirit of our invention.

What we claim as our invention, and desire to secure by LettersPatent, is

1. In a pneumatic-despatch-tube system, the combination of a tube; a gate extending across said pipe and separating same into two sec tions; means for exhausting the air from each section of said tube; meansfor closing the gate after the passage of a cartridge; and a valve opening to the outer air and controlled by the passage of the cartridge. for admitting air behind said cartridge after same has passed the gate, substantially as described.

2. In a pneumatic-despatch1tube system, the combination of a tube; a gate extending across said tube and separating same into two sections; .means for exhausting the air from each section of said tube; means for closing the gate after the passage of a cartridge; a valve opening to the outer air and controlled by the passage of the cartridge for admitting air behind said cartridge after same has passed the gate, and a timing device for controlling the closing of said valve, substantially as described.

3. In a pneumatic-despatch system,- the combination of a despatch-tube adapted to transacross said tube; a spring adapted to balance the Weight of said gate; means for exhausting the air from said tube; a suction-valve communicating with said means and located in front of said gate; mechanism operated by the cartridge and adapted to close said valve during the passage of the cartridge; said valve being located sufliciently far in front of said ,gate so that the air in the tube between said fvalve and gate will be compressed by the caritridge and start the opening of said gate, substantially asdescribcd.

have becomeequalized. When the cartridge finally arrives at the terminal, it'again causes a compression ofair in advance of same andopens the gate 111. After the passage of the 4. In a pneumatic-despatch-tube system,the

transmit acartridge along same; a gate extending diagonally across saidpipe, and being 5 suitably balanced so as to be normally open; :means. for admitting air to the tube behind j said gate and closing same after the passage of acartridge; means for exhausting the air from said tube; a suction-valve communicating with said means and located in .front'of said gate; mechanism operated by the cartridge and adapted to close said valve during the passage of the cartridge, said valve being located sufiiciently far in front of the gate so that the air in the tube between said valve and gate will be compressed by the cartridge and start the opening of said .gate, substantially as described. I

5. In a pneumatic-despatch-tube system,the combination of a tube adaptedto transmit a cartridge along same; a gate extending across said tube .and dividing said tube into two sections; means for exhausting the air from each of said sections; a suction-valve in said first section communicating with said means; an air-lnlet valve communicating with the second section of said tube near said gate; and pneumatic means for opening said suction and air valves after the cartridge has passed said gate;

substantially as described.

- 6. In a pneumatic-despatch-tube system,the combination of a tube adapted to transmit a cartridge along same; a gate extending across said tube and dividing same mto two sections;

means'for exhausting the air from each of said sections; a suction-valve in the first section communicating with said means; an airinlet valve communicating with the second section of said tube near said gate; and means controlled by the passage of said. cartridge and adapted to open said suction and air valves after the cartridge has passed said gate, substantially as described.

7. Ina pneumatic-despatch-tu be system, the

combination of a tube adaptedto transmit a cartridge along same; a gate extending across said tube and .dlvidlng same into two sections; means for exhaustlng the air from each of said sections; a suction-valve in the first sectioncommunicating with said means; an airinletvalve communicating with the second section of said tube nearsaid gate; pneumatic means'for opening said suction and air .valves a trip in said tube adapted to engage the car tridge after same haspassed said gate and operate said pneumatic means substantially as described. v Y

after the cartridge has passed said gate; and

8. The combination of a cylinderpapistonlslidably mounted insaid cylinder;- means'for exhausting the air from one end of said cylinder; an air-inlet at the other end of said cylinder; a by-pass connecting the ends of said cylinder, said by-pass being of less area than said inlet and being adapted to equalize the pressures on the opposite ends of the piston after said air-inlet has closed. substantially as described.

9. In a pneumatic-despatch-tube system,the combination of a tube adapted to transmit a cartridge along same; means for exhausting air from said tube; a valve for admitting air to said tube; a cylinder having a piston slidably mounted therein and connected with the air-valve in the tube; means for exhausting air from one end of said cylinder; an air-inlet at the other end of said cylinder; a by-pass connecting the ends of said cylinder, said bypass being of less area than said inlet and being adapted to equalize the pressure on the opposite ends of the piston after said air-inlet has closed, said piston being adapted to move when said air-inletis opened and thereby open said air-valve; a valve controlling said airinlet; and a trip in said tube adapted through engagement With the cartridge to open said air-inlet valve, substantially as described.

10. In a pneumatic-despatch-tube system, the combination of a'tube adapted to transmit a cartridge along same; means for exhausting air from said tube; a valve for admitting air to said tube; a cylinder having a piston slidably mounted therein and connected With the air-valve in the tube; means for exhausting air from one end of said cylinder; an air-inlet at the other end of said cylinder; a by-pass connecting the ends of said cylinder, said by-pass being of less area. than said inlet and being adapted to equalize the pressure on the opposite ends of the piston after said air-inlet has closed, said piston being adapted to move when said air-inlet is opened and thereby open said air-valve; a valve controlling said air-inlet; and a trip in said tube adapted through engagement with the cartridge to open said air-inlet valve; and means for automatically closing said airinlet valve after the air-valve for the tube has been openedby said piston, substantially as described.

11. In a pneumatic-despatch-tube system, the combination of a tube adapted to transmit a cartridge along same; a suction-pipe extending along said tube; a valve connecting said tube and pipe; a lever in said tube adapted to engage the cartridge and close said valve; and 'means for automatically opening said valve after said cartridge has passed a certain distance beyond same, substantially as described.

12. In a pnemnatic-despatch-tube system, the combination of a tube adapted to transmit a cartridge along same; a suction-pipe extending along said tube; a valve connecting said tube and pipe; means normally urging said valve into a closed position; a detent adapted to hold the valve open; and a trip extending into said tube and adapted through engagement with said cartridge to release the valve from said detcnt, substantially as described.

13. In a pneumatic-despateh-tulle system. the combination ol a tube adapted to transmit a cartridge along same; a gate extending across said tube and dividing same into two sections; means for exhausting air from each of said sections; a suction-valve in the lirst section communicating with said means; a trip in said first section adapted through engagement with a cartridge to close said suetion-valve before the arrival ol the cartridge, at the gate; and a trip in said seeond section adapted through engagement with the cartridge to cause the opening of said suctionvalve after the cartridge. has passed the gate, substantially as described.

14:. In a pneumatic-despatch-tnbe system, the combination of a tube adapted to transmit a cartridge along same; means lor exhausting the air from said tube; a stu:tion\'alve connecting said tube and said means; a spring normally urging the valve into its clo ed posit-ion; a detent adapted to hold said valve in its open position; and an arm extending into the tube and adapted through engagement; with the cartridge to move said detent and release the valve, substantially as described.

15. In a pnetnuatic-despateh-tulle system, the combination of a tube adapted to transmit a cartridge along same; a gate extending across one end of the tube and opening outward; a suction-pipe communicating wit h said tube near said gate, said suction-pipe being of considerably less diameter than said tube so that the air in advance of said cartridge will tend to be compressd by the movement of the cartridge and check the speed of same before its arrival at said gate, substantially as described.

16. In a pneumatic-despatch-tulie system, the combination of a tube adapted to transmit a cartridge along same; means for exhausting air from said tube; a despatch-box at one end of said tube adapted to receive the cartridge and having its walls suitably formed to inclose said cartridge; a gate separating said dospatch-box from said tube; an air-passage extending through the walls ol said despatchbox and having considerably less transverse area than said tube; an air-valvc communicating with said tube at a point beyond said despatch-box; means for opening said gate; and means for openil'ig said air-valve alter the cartridge has passed said gate, substantially as described.

17. In a pneumatic-despateh-tube system, the combination of a tube adapted to transmit a cartridge along same; means for exhausting air from said tube; a despateh-box at one end of said tube adapted to receive the eartridge and having its walls suitably formed to inelose. said cartridge; a gate separating said despatehbox from'said tube; an air-passage extending through the walls of said despatchbox and having considerably less transverse area than said tube; an air-valve communicating with said tube at a point beyond said gate; 'means for opening said gate; and mechanism for automatically opening said air-valve in a certain predetermined interval after the opening of said gate, sub'stantiallyas described.

18. In a pneumatic-despatch-tube system, the combination of a tube adapted to transmit a cartridge along same; means for exhausting airfrom said tube; aldespateh-box at one end of said tube adapted to receive the cartridge and having its walls suitably formed to inclose said cartridge; a gate separating said despatehbox from said tube; an air-passage extending through the walls of said despatch-box and having considerably less transverse area than said tube; anair-valve communicating with said tube at a point beyond said gate; means for opening said gate to cause the cartridge 'to enter the tube; means for automatically closing said gate after the passage of the cartridge; and mechanism for automatically opening said air-valve in a certain predetermined interval after the opening of said gate, substantially as described.

19. In a pneumatic-despatch-tiibe system,

the combination of a tube adapted to transmit a cartridge along same; means for exhausting air from said tube; a despatch-box at one end box from said tube; an air-passage extending through the Walls of said despateh-box and having considerably less transverse area than said tube; an air-valve communicating with said tube at a point beyond said gate; means for opening said gate to cause the cartridge to enter the tube; means for automatically closing said gate after the passage of the cartridge; -mechanism for automatically opening said air-valve in a certain predetermined interval after the opening of said gate; means normally urgingthe closing of said air-valve; and a timing device for controlling the closing of said air-valve, substantially as described. Signed at New York, N. Y., this 17th day of April, 1904:- y

. WILLIAM H. DINSPEL. -Witnesses:

' F. S. VAN VVART,

MAX GREENWALD. Signed at Chicago, Illinois.

JOSEPH J. STOETZEL. Witnesses: WILLIAM L. HALL, D. H. JACKMAN.

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