US1970826A

US1970826A - Pneumatic motor

Info

Publication number: US1970826A
Application number: US659005A
Authority: US
Inventors: Charles S Tankersley
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-02-28
Filing date: 1933-02-28
Publication date: 1934-08-21
Anticipated expiration: 1951-08-21

Description

AU8- 21, 1934- c. s. TANKERSLEY 1,970,826

PNEUMATIC Mo'ion Filed Feb. 2s. s1935 4 sheets-sheet 1 R 3 ,a Z M IIIIIIHJ C S@ Tamb/Sieg E" ATTORN EYS Aug. 2l, 1934. c. s. TANKERSLEY 1,970,826

PNEUMATIC Mo'ron 4 Filed Feb. 28. 1933 4 Sheets-Sheet 5 26 30 24J 2.9 (j 751'?, i 6' /ll oo 1bn/afslag INVENTOR ATTORNEYS Aug. 2l, 1934- c. s. TANKERsLEY PNEUMAT I C MOTOR Filed Feb. 28, 1935 4 sheets-sheet 4 /V f w IK A .m j c.

Patented vug.` 2l,

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'1 olaimsgf" (c1. 1er-34)V This invention relates to new and useful provements in pneumatic motors.

pneumatic motor which may be made suiiiciently light in weight and small enough in sizeto be' readily handled by a single workman for performing various operations, such as operating` a wrench for tightening nuts and bolts, or other small tools,- or for applying power wherework is usually done manually, such as the cranking of airplane motors and the like.

A particular object of the invention is to provide a motor having a reversing valve arranged so as to be quickly and easily operated, `and especially one in which the same ports are used for driving in either direction, thus eliminatin a dual set of ports or passages.

An important object of the invention is to provide an air motor of the light portable type, in which stuffing boxes and similar packing elements are entirely eliminated, whereby the motor is made substantially air-tight and is not likely to be distorted or sprung when dropped and thereby cause air leaks either within or Without the casing.

Another objectof the invention is to provide a valve mechanism wherein the lluid pressure is utilized to Ahold the controlling elements in contact and to prevent leaks therebetween.

A still further object of the invention is to provide an air motor in which the exhaust fluids are conducted to a separate chamber within the casing and thus excluded from the crank case; -and also wherein the actuating means for reversing the valve is located in the exhaust chamber, which eliminates the necessity of packing, particularly in connection with the operating lever.

Another object of the invention is-to provide an air motorin which the power takeoff or tool connection is located at the outer margin of the motor, whereby work in corners and angles may be done; and in connection with an oppositely directed handle an increased leverage obtained.

A further object of the invention is to provide a valve mechanism and a drive therefor in which wear is automatically taken up and leaks which would otherwise result are eliminated.

A construction designed to carry out the nvention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in

which an example o! the invention is shown,- and Y I wherein: A One object of the invention is to vprovide a1 ,FigureY 1 is arearY elevation illustrating a pneumatic motor constructed in accordance with my invention, Y

Figure 2 is a fragmentary front elevation partly in section and illustrating the reduction gears for the motor,

Figure 3 is motor, Y Y

Figure 4v is a fragmentary vertical` sectional Yview showing the Yinterior ofthe motor and the a. siderrelevaudn mustrating the Figure 8 is a plan view illustrating the rotatable so cap or plate of the control valve,

Figure 9 is a plan View illustrating an opposite face of the cap or plate from that shown in Figure 8,

Figure 10 is a plan view illustrating the intermediate plate of the valve, u

Figure 11 is a plan view illustrating the shifting spider or plate of the Valve, Y

Figure 12 is a fragmentary sectional View illustrating the handle for manipulating the device and controlling the main valve,

Figure 13 is a detail sectional view illustrating one of the pistons of the motor,

Figure 14 is a detail view illustrating an oil groove to establish communication between the lubricant chamber and the air supply passage of the device,

Figure 15 is an enlarged diametrical sectional view through the valve and component parts of the motor,

Figure 16 is a vertical sectional view taken on the line 16-16 of Figure 15, and showing the valve mechanism shifted for operating the motor in a clockwise direction, and

Figure 17 is a similar view showing the valve mechanism adjusted to drive the motor in va counter-clockwise direction. s

Referring in detail to the drawings, the numeral 1 indicates a cylindrical crank case having formed integrally therewith radially extending cylinders 2 in which are Areciprocally mounted los ioA

pistons 3 carrying removable connecting members 4 to which connecting rods 5 are pivoted. The inner end of each connecting rod is formed integrally with said rod and surroundsand supports an anti-friction bearing 6 which receives the crank 7 of a crank shaft 8 located centrally of the crank case. It is to be noted, however, that the outer ends of the cylinders are shown integral with said cylinders. This eliminates packing gaskets which are required when removable heads are used, and the danger of rupturing or displacing the head when the motor is dropped or roughly used, is avoided. The ends of the crank case are closed by

removable heads

9 and 10 equipped with bearings 11 that rotatably support the crank shaft.

A gear housing 12 is removably secured to the head 10 and extends parallel with one of the cylinders to the outer end thereof. 'I'he head 10 also-is provided with an extension which extends parallel with the cylinder above referred to and cooperates with the cover of the gear housing in enclosing a train of speed reducing gears 13, one of which is secured to the crank shaft while another is secured to a power take-off shaft 14. The shaft 14 is supported by the extension on the head 10 and .by a thrust bearing 15 carried by the cover of the timing gear case. The power takeoi shaft may be of any desired construction so that any conventional type of wrench, socket or coupling tool may be connected thereto.

The outer face of the head 9 has formed therein an annular exhaust recess or chamber 16 communicative with exhaust ports 17 formed in the contiguous walls of the crank case. A valve plate 18 is secured to the crank case over the chamber 16 of the head 9 and is provided with passages 19 in continuous communication with said exhaust. One end of the crank shaft extends through the head 9 and plate 18 into a removable housing 20 secured to the plate 18. The housing cooperates with the plate 18 in forming a chamber 21 in which a control valve mechanism 22 is located, the purpose of which is to controlpassage of the pressure fluid to and exhaust from the cylinders. Formed integrally and in communication with the housing 20 is a pressure uid supply pipe 23 connected to a valve case 24 positioned between two of the cylinders. This case is connected to a handle 25 which is suitably secured to the crank case and provides a medium for permitting the tudinally alined with cylinders on each side thereof, whereby the motor is balanced when the handle 25 is held by the workman.

The handle also provides a medium for conveying air or other pressure fluid to the motor by having its outer end equipped with a fitting 26 to which a hose 27 is connected for supplying a pressure fluid. The handle is in communication with the valve case 24 and the latter has located therein a rotatable valve 28, the stem of which carries a gear segment 29 meshing with a segmental gear 30 on a sleeve 31 journaled on the handle proper. The sleeve is provided with a spiral spring 32 for normally urging the sleeve in a position to close the valve 28 and which will permit the sleeve to be manually turned in one direction for opening the valve to allow pressure fluid to enter the chamber 21. Formed in the handle is a lubricant chamber 33 adapted to be supplied with lubricant through a fitting 34.' A pressure fluid conducting tube 35 extends from the fitting 26 through the chamber 33 to the reduced bore of the handle. Lubricant in limited amounts may pass through a groove 33' located in the tube 35 whence said lubricant may pass into the interior of the motor along with the pressure fluid for lubricating the various moving parts of said motor. Surrounding the tube 35 at the bottom of the lubricant chamber is a felt washer 35 which allows a slow movement of the lubricant into the groove 33'. It is to be understood that the lubricant is in the form of an oil; Communicating pressure fluid ducts 36 are formed in the plate 18 and walls of the cylinders 2. These ducts communicate with the interior of the cylinders at their outer ends and with the chamber 2l. The communication between said ducts and the chamber 21 is controlled by the valve mechanism 22.

The valve mechanism 22 consists of an oscillating or shifting circular spider 37, an intermediate disk 38 and a cap or outer disk 39. The spider 37 is formed with an axial sleeve 40 which surrounds one end of the crank shaft and extends inwardlyl through an opening in the plate 18 into the exhaust chamber 16. A gear 41 fastened on the inner end of the sleeve meshes with a gear segment 42 secured on the end of an operating shaft 43 extending through the plate 18. Because the gear and segment are located in the exhaust chamber, no stufling box or other packing is required for the shaft 43. An exterior handle 44 -is fastened on the shaft and by swinging the handle in opposite directions the spider will be oscillated accordingly.

The spider 37 and intermediate disk 38 have a rotating fit in the housing 21 and this maintains the circular portion of key-hole opening 47 in said disk in registration with the bore of the sleeve` 40, whereby constant communication is had between the exhaust cha'mber 16 and the cap 39, by way of the passages 19 and a port in said sleeve. l

The spider is formed wth/ elongated arcuate slots 45 located to register lwith the ducts 36, one with each of the three ducts. The disk 38 has equally spaced ports 46 in registration with the slots 45 of the spider. The rotation or oscillation of the disk 38 is limited by a stud 20 (Figures 16 and 17) carried by the cover 20 and engaging in a peripheral groove 38 in the edge of said disk. Motion is imparted to the disk, when the spider is shifted, by a pin 48 engaging in the bottom of opening 47. The cap 39 has formed centrally thereof an outwardly directed dome 49 and communicating therewith an arcuate channel 50 located, and of such length, as to cover two of the ports 46. The outer edge and under surface of the cap has a turning fit on the disk 38 which may be slightly larger than the cap. The pressure fluid in the chamber 21 will hold the

valve members

37, 38 and 39 in such intimate contact as to prevent leaks therebetween as well as preventing 'leaks between the spider and the plate 18. A helical spring 52 surrounding the dome and engaging the inner wall of the housing 20 serves to hold the valve members in place when they are not under uid pressure.- A coiled spring 52 surrounding the sleeve 40 between the plate 18 and the gear 41, acts to urge the sleeve and gear inwardly, thereby holding the spider 37 in intimate contact with the outer face of theplate 18 and also compressing a packing washer against the inner wall of the exhaust chamber, as is clearly shown in Figures 4 and 15.

A cross pin 51 in the dome engages in a notch 51' in one end oi the crank shaft (Figures 4 and 15) for the purpose of rotating said cap. Because of the length of the slot, wear between the valve members is automatically taken up. It is to be noted that the end of the shaft is covered by the dome 49. As is best shown in Figures 8 and 9, the marginal portion of the cap 39 is formed with an arcuate opening or recess 53 located to successively move over and uncover the ports 46 when the cap is rotated by the crank shaft. Thus two of the ports are constantly covered by the cap Vwhile one is open to allow the pressure fluid to pass through to one of the slots 45 of the spider and from thence to one of the ducts 36. During more than one half of each rotation of the cap the channel 50 will be over oneor more of the ports 46, and thus communication is established betweenY the ducts 36 and the exhaust chamber 16 by way of the opening 47, sleeve 40, port 40', and

' passages 19.

In operation, the hose 27 is connected with a suitable source of pressure iiuid supply and for the purposes of explanation, it will be assumed that compressed air is the fluid supplied. The handle sleeve 31 is held by the operator in one hand, while the outer end of the handle 25 is held in his-other hand. By rotating said sleeve theV valve 28 is opened, whereby airis supplied to the chamber 21. One of the ports 46 being exposed by the recess 53 of the cap 89, the air passes through said port to the communicating slot 45 -of the spider 37 and thence into the duct 36 which is in registration with said slot as is shown in Figures 4, 5, 15, 16 and 17. The compressed air will flow through the duct 36 to the outer end of its respective cylinder and drive its piston 3 inwardly, whereby rotation will be imparted to the crank shaft and the valve mechanism 22, thus starting the motor.

In order to clearly explain the operation of the motor, I have designated in Figures 16 and 17 (only) the ducts 36 as 1, 2 and 3, and the ports 46 as A, B and C. It will be noted thatwith the motor and the valve member 39 rotating in a clockwise direction (Figure 16) and the disk 38 and spider 37 stationary, the slots 45, which establish communication between the ports 46 and the ducts 36, are in a particular relation. When the

valve members

37 and 38 are shifted in a counter-clockwise direction to reverse the valve, the slots 45 are moved so that the -slot 45, which in Figure 16 establishes communication between duct 1 and port A, is'movecl'to establish communication (Figure 17) between the duct l and the port C. Thus where the air was being supplied to oneV cylinder through port A and duct 1 and the slot 45 connecting them, the same slot will conduct air from port A to duct 2 of the. next cylinder `to the right (Figure 17) when the valve is reversed.' The cylinders marked 1, 2 and 3 may be referred to as rst, second and third cylinders; while the ports marked A, B and C may be referred to as iirst, second and third ports. It is pointed out that the disk 38 and spider 37 do not move, except when the motor is reversed.

It will be presumed that the motor is started rotating in a clockwise direction with the valve turning in the direction of the arrows (Figures 5 and 16). Rotation being imparted to the cap 39 the first port 46 or A in Figure 16, to which air is being supplied and which'supplies it to duct 1, Figure 16 will be covered before' the piston completes its power stroke. The second port 46 or B in Figure 16 is next uncovered so as to admit of the slots 45, in a counter-clockwise direction air to the duct 2 in Figure 16 of the second cylinder and the charme] 50 of the cap moves over the rst port 46 or A in time to establish communication between the duct 36er 1, Figure 16 of the rst cylinder and exhaust chamber 16 by way of the opening 47, sleeve'40, port 40', and passage 19. VAfter the second cylinder has operated the continued rotation of the valve cap 39 uncovers the third port 46 or C in Figure 16 of the

duct

36 or 3 in Figure 16 of the third cylinder. The channel 50 will also move over the second port 46 or B in Figure 16 and thus exhaust the second cylinder. The air pressure holding the valve members seated and the exhaust air passing through the channel 50 assures against air leaks. obviates the use of packings, and makes for more elcientoperation. 'Ihe exhaust passing to the chamber 16 and escaping through the ports tok atmosphere is excluded from the crank case 1. By observing Figure 5, it will be noted that by reason of the recess 53, air is supplied to only one of the ports 46 at a time, and the other two ports are Vcut oil" from the air supply and are either covered by the back face of the cap 39 100 or are in communication with the channel 50, which in turn is in constant communication with the exhaust chamber 16. This is true except at the instant the gap 53 in the cap 39 is uncovering one port and covering the trailing port, which will occur when the advance piston is at top of dead center. The slots 45 in the spider 37 establish communication between particular ports and particular ducts and, therefore, one slot will be conducting air from one port to one duct, while the other two slots will be conducting air from the other two ducts to the other two ports.

It is obvious that if the upper left hand slot 45 in Figure 16 is conducting air from the port A to the duct 1, the right hand slot 45 in Figure 115 16 will be conducting exhaust air from the duct 2 to the port B. Now, should the spider be shifted in a counter-clockwise direction, the right hand slot in Figure 16 will be moved to the left, whereby port A will be connected with duct 2. Duct 2, being connected with a cylinder in which the piston is traveling outwardly on its exhaust stroke,

it is obvious that when the port A is connected with said duct, air will be supplied to said cylinder, whereby the travel of the piston win be V reversed and also the direction of rotation of the'motor will be reversed. In order to reverse the direction of rotation of the motor, it is merely necessary -to swing the lever 44 from the position shown in Figure 16 to that shown in Figure 17. This will rotate the shaft 43, which in turn will rotate the elements 42, 41 and 40 (Figures 4 and 6), whereby the spider 37 will be moved in a counter clockwise direction (Figures 16 and 17).

During the initial movement of -the spider the pin 48 will travel in the bottomof the opening 47 without imparting rotation to the disk 38. This initial-movement of the spider will move the solid webs or legs, which separate the ends and cause them to pass under the stationary Y ports A, B and C (Figure 16), whereby communication between each port and the slot ex- .tending counter-clockwise therefrom will be During the initial movement of the spider the disk 38 has remained stationary, and the pin 48 is traveling in the opening 47; but when the pin 48 reaches the other side of the opening 47, the disk 38 will be shifted in a counter-clockwise direction until arrested by the stud 20', as shown in Figure 17. It is necessary to move the disk 38 to position the ports with relation tothe recess 53 of the cap and thereby give the motor a lead in advance suilicient to supply air to reverse it. When the reversing is effected, as above described, the cap 39 is traveling in a clockwise direction, but as soon as the reverse is completed,'said cap will begin to travel in a counter-clockwise direction and, therefore, it is necessary to shift the port A so as to give the second cylinder connected with the port 2 sufcient advance or lead.

It is pointed out that only a single set of ports is used for driving in either direction and this greatly simplifies the reversing means. By locating the reversing actuators in the exhaust chamber and closing off said chamber from the crank case, any leaks around the shaft 43 would be of no consequence and thus packing is not required. The terminating of the crank shaft and withinthe dome 49 of the valve cap permits the housing 20 to be made imperforate, except for the fluid pressure entrance. It also obviates by-passing of the pressure fluid along the crank shaft. The crank shaft being entirely in the exhaust passage, no packing is required and leaking would not interfere with the operation. The valve members being seated by the pressure fluid, obviate leaking therebetween.

In order to make the motor useful for its purpose, it must be made small and light in weight. The single set of ports in the disk 38 permits the making of a very small valve, which would be impossible if two sets of ports were necessary. It is preferable to extend the train of gears 13 along the cylinder 2, which is diametrically opposite from the handle 25. This not only balances the motor, but it enables the shaft 14 to be connected with devices and the same operated in corners and comparatively close angles. By keeping the exhaust fluids and the pressure fluids entirely separated, as Well asv by closing off the exhaust.

chamber from the crank case, the chance of leakage, whereby these uids would commingle, is reduced to a minimum and a higher efficiency is obtained.

The description which has been given recites more or less detail of a particular embodiment of the invention, which is set forth as new and useful; however, I desire it understood that the invention is not limited to such exact details of construction, because it is manifest that changes and modifications may be made, within the scope of the appended claims, without departing from the spirit of the invention. y

What I claim and desire to secure by Letters Patent, is: y

1. A pneumatic motor comprising, a crank case, cylinders extending from said case, a crank shaft 'journaled in said case, pistons operating in said cylinders and connected with said crank shaft, a stationary exhaust chamber at one side of the crank case and closed olf therefrom, a fluid pressure chamber at the same side of said case and outwardly of said exhaust chamber, the exhaust chamber having an opening to atmosphere, ducts leading from the pressure chamber to the outer ends of the cylinders, a rotating valve mechaanism including a member for admitting pressure fluid to the ducts and for conducting exhaust fluids from the ducts to the exhaust chamber,

reversing means for reversing the valve mechanism located in the exhaust chamber and connected with the valve mechanism, and an exterior operator connected with the reversing means.

2. A pneumatic motor comprising, a crank case, cylinders extending from said case, a crank shaft journaled in said case, pistons operating in said cylinders and connected with said crank shaft, a stationary exhaust chamber at one side of the crank case and closed oif therefrom, a fluid pressure chamber at the same side of said case and outwardly of said exhaust chamber, the exhaust chamber having an opening to atmosphere, ducts leading from the pressure chamber` to the outer ends of the cylinders, a valve mechanism in the pressure chamber comprising a spider having vopenings registering with the ducts and a disk having ports registering with the openings of the spider and a rotating cap having an opening for exposing the ports of the disk and a chanel. the openings of the spider being in constant communication with the ducts, a passage extending from the` exhaust chamber constantly open to the channel of the valve cap, a driving connection between the crank shaft and the valve cap, means within the pressure chamber for holding the cap in contact with the disk, reversing means in the exhaust chamber connected with the spider, an exterior operator connected with the reversing means, and a connection between the spider and the disk for rotating the latter when the spider is rotated.

3. A pneumatic motor comprising, a crank case, cylinders extending from said case, a crank shaft journaled in said case, pistons operating in said cylinders and connected with said crank shaft, a stationary exhaust chamber at one side of the crank case and closed oil' therefrom, a fluid pressure chamber at the same side of said case and outwardly of said exhaust chamber, the exhaust chamber having an opening to atmosphere, ducts leading from the pressure chamber to the outer ends of the cylinders, a valve mechanism in the pressure chamber comprising a spider having openings registering with the ducts and a disk having ports registering with the openings of the spider and a lrotating cap having an opening for exposing the ports of the disk and a channel, the openings of the spider being in constant communication with the ducts, a passage extending from the exhaust chamber constantly open to the channel of the valve cap, a driving connection between the crank shaft and the valve cap, means within the pressure chamber for holding the cap in contact with the disk, reversing means in the exhaust chamber connected with the spider, an exterior operator connected with the reversing means, a connection between the spider'and the disk for rotating the latter when the spider is rotated, and spring means for holding the spider against the inner wall of the pressure chamber.

4. A pneumatic motor comprising, a crank case, cylinders extending from said case, a crank shaft journaled in said case, pistons operating in said cylinders and connected with said crank shaft, a uid pressure chamber carried by the crank case, ducts leading from said chamber to the outer ends of the cylinders, an exhaust passage leading from the pressure chamber, a rotatable valve spider in the chamber having openings in communication with the ducts, a valve disk having a single set of ports registering with the openings of the spider, a shifting connection between the spider and the disk, the spider and disk having openings registering with the exhaust passage, a rotating cap connected with the crank shaft and having an opening for exposing the ports of the disk in the pressure chamber and a channel for connecting said ports with the opening to the exhaust passage, and a single reversing means'connected with the spider.

5. As a sub-combination in a multi-cylinder pneumatic motor, a valve mechanism comprising, a rotatable spider having a central fluid passage and arcuate uid passage openings surrounding said central openings, a rotatable disk having a fluid-tight bearing on the spider and provided with a. single set of ports in registration with the arcuate uid passages of thespider and a central opening in registration with the central opening of the spider, a connection between the spider and the disk arranged to permit initial rotation of the spider and subsequent rotation of the disk by the spider, a rotating cap tting on the disk having an opening for successively exposing the ports of the disk and a channel for connecting said ports with the central opening of the disk, and means for adjusting the spider to shift its relation to the disk.

6. As a, sub-combination in a multi-cylinder pneumatic motor, a valve mechanism comprising, a rotatable spider having a central uid passage and arcuate uid passage openings surrounding said central openings, a rotatable disk having a uid-tight bearing on the spider and provided with a single set of ports in registration with the arcuate uid passages of the -spider and a central opening in registration with the central opening of the spider, a. connection between the spider and the disk arranged to permit initial rotation of the spider and subsequent rotation of the disk by the spider, a rotating cap fitting on the disk having an opening for successively exposing the ports of the disk and a channel for connecting said ports with the central opening of the disk, and a single reversing means connected with the spider.

7. A pneumatic motor comprising, a crank case, cylinders extending from said case, a crank shaft journaled in said case, pistons operating in said cylinders and connected with said crank shaft, a stationary exhaust chamber at one side of the crank case and closed off therefrom, a,

uid pressure chamber at the same side of said case and outwardly of said exhaust chamber, the exhaust chamber having an opening to atmosphere, ducts leading from the pressure cham`