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Publication numberUS3477793 A
Publication typeGrant
Publication dateNov 11, 1969
Filing dateFeb 4, 1969
Priority dateFeb 4, 1969
Publication numberUS 3477793 A, US 3477793A, US-A-3477793, US3477793 A, US3477793A
InventorsTaisuke Kitagawa
Original AssigneeTaisuke Kitagawa
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Pneumatic rotative machine
US 3477793 A
Abstract  available in
Images(4)
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Claims  available in
Description  (OCR text may contain errors)

Nov. 11, 1969 TAISUKE KITAGAWA 3,477,793

PNEUMATIC ROTATIVE MACHINE Filed Feb. 4, 1969 4 Sheets-Sheet;

By. I 8

INVENTOR.

N 1969 TAISUKE Kn'AcsAwA 3,477,793

PNEUMATIC ROTATIVE MACHINE 4 Sheets-Sheet 2 Filed Feb. 4, 1969 IN VEN TOR.

N 1969 TAISUKE KITAGAWA 3, 77,793

PNEUMATIC ROTATIVE MACHINE 4 Sheets-Sheet 3 Filed Feb. 4, 1969 BY ul lwiuwi gLL ATTORNEY;

N v. 11, 1969 TAISUKE KITAGAWA 3,477,793

I PNEUMATIC ROTATIVE MACHINE Filed Feb. 4, 1969 4 Sheets-Sheet 4 7n 15a AF AITAGnu/A. INVENTOR A'ITORNEY5 United States Patent US. Cl. 415--36 7 Claims ABSTRACT OF THE DISCLOSURE A pneumatically driven rotating machine, a rotor having bladesthereon is rotatably positioned within a casing with the blades cooperating with the casing for rotation of the rotor when air is directed into the casing against the blades. A torque transmitting plate is mounted on a driving shaft extending from the rotor, and a torque receiving plate is mounted on a driven shaft adjacent the torque transmitting plate. Cutout portions are provided in the peripheries of said plates, and spring means couples the plate for transmitting torque between said plates. The cutouts are out of alignment when the torque transmitted is near zero and are in alignment when the torque transmitted is a maximum, so that the air passed through the machine is increased as the torque is increased and decreased as the torque is decreased.

.This application is a continuation-in-part of Ser. No. 562,565, filed July 5, 1966, now Patent No. 3,430,920.

This invention relates to pneumatic rotative machines having a rotor with blades which is rotated by air current, such as pneumatic grinders, pneumatic drills, air motors, etc. and has for an object to provide such a. machine with novel mechanism whereby rotation is automatically controlled according to the load.

Another object of the present invention is to control the supply of compressed air to the most economical quantity by adjusting automatically the exhausting capacity of the above-mentioned machine and to effect such control on stepless basis and by perfect automatic action.

Still another object of the present invention is to provide adjustment of exhausting capacity free from wear due to high-speed revolution by using a simple coupling device which is free from high-speed friction between a transmission shaft. 7

A further object of the present invention is to provide a reversible type of the above-mentioned machine which can achieve all of the foregoing objects, with its torque receiving shaft made revoluable both clockwise and counterclockwise by giving slight modification to the above-mentioned coupling device.

The accompanying drawings show some embodiments of the present invention, in which:

FIG. 1 is avertical-sectional side elevation of the body of the pneumatic rotative machine with its front part and rear part omitted,

FIG. 2 is a front elevation of the torque receiving plate,

. FIG. 3 is a sectional view, as taken along the line AA of FIG. 2,

FIG. 4 is a rear elevation of the torque transmitting plate,

FIG. 5 is a side elevation, as taken along the line BB of FIG. 4,

FIG. 6 is a side levation showing the coupling device by which the above-mentioned torque receiving plate and torque transmitting plate are coupled,

FIG. 7 is a perspective view of the construction shown in FIG. 6,

3,477,793 Patented Nov. 11, 1969 FIG. 8 and FIG. 9 show another embodiment of the torque receiving plate respectively, in which FIG. 8 is a front elevation and FIG. 9 is a sectional view, as taken along the line Aa-Aa of FIG. 8,

FIG. 10 shows a rear elevation of the torque transmhiitting plate of reversible type pneumatic rotative mac me.

FIG. 11 is a perspective view of the coupling device in which the torque transmitting plate shown in FIG. 10 gsmaltegd with the torque receiving plate shown in FIGS.

FIG. 12 through FIG. 14 show respectively a relative position, in rear elevation, of the torque transmitting plate and the torque receiving plate, in which FIG. 12 showing the state where cutout portions are totally closed, FIG. 13 showing the state where the torque transmitting plate revolved clockwise from the position of FIG. 12, and FIG. 14 showing the state contrary to that shown in FIG. 13,

FIG. 15 shows a different embodiment from the coupling device shown in FIG. 11, in which cutout portions in FIG. 11 are replaced by small holes, and the torque receiving plate is shown as it is cut away in part, and

FIG. 16 corresponds to FIG. 12, in which the cutout portions being replaced by small holes, and is a rear elevation showing the relative position of the torque transmitting plate and the torque receiving plate.

Referring to the conventional pneumatic rotative machines, a pneumaic rotary air motor driven by compressed air, for example, has a device with the following mechanism, i.e., a rotor having many blades movably and radially disposed therein is accommodated eccentrically in a cylinder, compressed air is supplied in such a manner that it flows from one end of a crescent-shaped gap formed between said cylinder and rotor to the other end, said compressed air is caused to act upon the blades of the rotor and imparts rotation to the rotor axis, which rotation is transmitted to the transmitting shaft through the medium of a spline, gear, etc. for the use of a certain kind of work.

This kind of pneumatic machine is supplied with the air of a given pressure, in a fixed quantity and continuously. Where this compressed air acts upon the blades and causes the rotor axis to rotate, if the exhausting capacity of it is not controlled, said rotor will maintain high-speed revolution. However, so long as the transmission shaft is running idle, it is of no use to maintain high-speed revolution or rather it is only the waste of the air. Moreover, it only hastens the wear of sliding parts of the machine the more to maintain high-speed revolution at all times. Conventional pneumatic rotative machines are not provided with proper means to solve this problem and even if it is provided, it is too complicated in mechanism and is not considered satisfactory. Moreover, the torque receiving shaft of conventional pneumatic rotative machine is revolvable only in one direction and it is not easy to make it reversible.

The present invention relates to a pneumatic rotative machine, wherein a torque transmitting plate is connected with a drivingshaft of a rotor with blades, a torque receiving plate disposed opposite the said torque transmitting plate is fixed to a transmission shaft, and said torque transmitting plate and said torque receiving plate forma coupling device through the medium of a spring, thereby adjusting a gap for exhausting automatically by the relative displacement of said coupling device in proportion to the change of load acting upon the transmission shaft and thus controlling rotation. Furthermore, by making cutout portions properly in the coupling device the torque receiving plate can be made reversible in its rotatory direction.

Now, the present invention is described hereinafter more specifically with reference to the accompanying drawings showing its embodiments. In the drawings, 1 designates a main body of the pneumatic rotative machine, accommodating therein a cylinder 4 carrying a rotor 3 having many blades 2 arranged radially, a torque transmitting plate 5 and a torque receiving plate 6, both of the two plates being described in detail hereinafter. Said rotor 3 is supported at its both ends by support members 8, 9 through the medium of. bearing 7. A screwed part 10 of said torque transmitting plate 5 is screwed in the front end portion of the rotor 3 to have them fixed integrally, in front of which is disposed a torque receiving plate 6. Thus, the peripheries of said two plates 5, 6 keep a slight gap in relation to the inner surface of the main body 1. On the periphery of the torque transmitting plate 5 are made cut out portions 11 oppositely in a diametral direction, in front of which are provided two protrusion pieces 13 oppositely in a diametral direction. At the center of the torque receiving plate 6 with its front part formed in a cone shape is bored a hole 14 having a key way, On the rear surface of which are provided oppositely in a diametral direction arc-shaped grooves 15 in a circumferential direction. Inserted in each of said grooves is a coiled spring 16. 17 denotes cutout portions provided oppositely in a diametral direction on the periphery of flanged part. Therefore, where said torque transmitting plate 5 and said torque receiving plate 6 were accommodated in the main body 1 at their respective position, the protrusion piece 13 of the torque transmitted plate 5 is engaged in the end portion of the arc-shaped groove 15 of the torque receiving plate 6 and thus the cutout portions 11, 17 on the peripheries of the two plates 5, 6 are coupled in such a fashion as shown on FIG. 6 and FIG. 7. These cutout portions form exhaust passages, and the size of the gap D varies according to the state of coupling, which naturally determines the exhausting capacity. Depending upon the size of a gap between the peripheries of said two plates 5, 6 and the main body 1, said gap D can be dispensed with. While said exhaust passage or gap D is connected at its front end with an exhaust port 18 formed between the torque receiving plate 6 and the main body 1 and leading to the outside of the main body 1, it is connected at its rear end with an exhaust chamber 19 formed at the periphery of the torque transmitting plate 5. Said exhaust chamber 19 is connected with another exhaust chamber 20 formed between the cylinder 4 and the main body 1 and is further connected with an air supply port 22 through the medium of space 21 between blades 2. Numeral 23 denotes a transmission shaft which is supported by bearing 24 and its end is keyed in the hole 14 of the torque receiving plate 6. Compressed air to be supplied to space 21 passing through the air supply port 22 acts upon the blades 2 of the rotor 3, causes the rotor to rotate and is exhausted from the exhaust port 18 passing through the exhaust chambers 19, 20 and the gap D. At this time, rotation given to the rotor 3 is transmitted to a coiled spring 16 through the protrusion piece 13 of the torque transmitting plate 5 and is further transmitted to the driving shaft 23 through the medium of the torque receiving plate 6. In this case, when the transmission shaft 23 is not loaded, torque is transmitted only by the protrusion piece 13 of said torque transmitting plate 5 moving slightly and pressing the coiled spring 16. In this case, because the relative displacement of the two plates 5, 6 is very small, the exhaust gap D is necessarily restricted, with the result that consumption of the air is restricted so much. On the other hand, when the load acted upon the transmission shaft 23, braking force acts upon the torque transmitting plate 5 and in order to rotate the shaft, the torque transmitting plate 6 is required to press the coiled spring 16 stronger than in the case with no-load and transmit accumulated repulsive force of said coiled spring to the torque receiving plate 6. In this case, therefore, the relative displacement of the torque transmitting plate 5 and the torque receiving plate 6 increases, with the result that the gap D at the end of cutout portions 11, 17 of the two plates is made larger and, in its turn, exhausting capacity increases-and stronger torque works. In other words, the relative displacement of said two plates 5, 6 varies according to the load which acts upon the transmitting shaft 23.

Provided on the torque receiving plate 6 is'a stop pin 25'which is intended for checking the relative displacement of the torque transmitting plate 5 andthe-torque receiving plate 6 within a fixed quantity. The use of leaf springs in place of coiled springs as shown on FIG- 8 and FIG. 9 for another embodiment of the' torque-receiving plate 6, is also desirable. In the description made hereinbefore of the torque receiving plate 6, the coiled spring 16 is inserted in the arc-shaped groove 15, whereas the leaf spring 16a is disposed radially within a concave 15a provided on the torque receiving plate-6a and the base part 26a of the leaf spring is fixed to thebase 27a of the concave 15a in such a manner that the protrusion piece 13 of the before-mentioned torque transmitting plate 5 makes contact with the tip of the leaf spring. With the exception of this difference, there is no difference in the shape of each part between the two embodiments, as indicated by numerical symbols with an additional mark a in FIG. 8 and FIG. 9. Air controlling action by means of the coupling of the two plates 5, 6 is almost the same in either case.

The coupling device mentioned above is of non-reversible type but it is possible to make it reversible by giving it slight modification, as described below.

In lieu of cutout portions 11 on the torque transmitting plate 5 shown in-FIG. 4 and FIG. 5, cutout portions 11b and are made on either side of non-cutout portions 1111, both being almost equal in their peripheral width, as shown by FIG. 10. In lieu of the protrusion piece 13, a pair of protrusion pieces 13b is provided opposite to each other with a slight gap 13c therebetween. With the exception of these modifications, a torque transmitting plate 5b is the same as the torque transmitting plate 5 shown by FIGS. 4 and 5. The torque receiving plate to mate with this torque transmitting plate 5b can be of the same construction as that shown in FIGS. 8 and 9, but its cutout portions 17a should have almost the same peripheral width as that of the above-mentioned torque transmitting plate 5b. By fitting the spring 16a of the torque receiving plate 6a in the gap 13c of the protrusion pieces 1312 the torque transmitting plate 5b is mated with the torque receiving plate 6a and thus the coupling device is assembled. By employing this coupling device, the non-reversible type pneumatic rotative machine can be made reversible in its function. As shown by FIGS. 12 through 14, by means of this coupling device gaps for exhausting are made variable, i.e., closing, right-side opening and left-side opening in relation to the cutout portions 17a, more particularly, in the state shown by FIG. 12 cutout portions of both the torque transmitting plate 5b and the torque receiving plate 6a are all blocked up, wherein the spring 16a is in neutral, no exhausting is made and the rotor 3 is standing. In this state, if load acts clockwise upon the torque transmitting shaft 23, the torque transmitting plate 5b shows relative displacement in a counterclockwise direction, with the result that gaps 30 are made as shown by FIG. 13. Such gaps are variable with the magnitude of load and accordingly exhausting range from closing to .maximum, involving the rotation of the rotor 3. If load acts counterclockwise, gaps 31 are made on opposite side as shown by FIG. 14 and the rotor 3 is caused to revolve in an opposite direction by exhausting. Thus, this coupling device enables the pneumatic rotative machine to work on reversible basis. Furthermore, all cutout portions hereinbefore mentioned could be replaced by holes made in the torque transmitting plate and the torque receiving plae. For example, the pneumatic rotative machine of reversible type under the present invention could be obtained by means of the coupling device wherein cutout portions as indicated by FIG. 11 are replaced by small holes as indicated by FIG. 15 with no change in the other parts, i.e., cutout portions 11b and 110 of torque transmitting plate 5b in FIG. 11 are replaced by small holes 112 and 11f of torque transmitting plate 50 in FIG. 15, and cutout portion 17a of torque receiving plate 6a in FIG. 11 is replaced by a small hole 17b of torque receiving plate 6b in FIG. 15. These small holes should be the same in diameter and a non-cutout portion 11d of the same space as the diameter of small hole is provided between small holes 1112 and 11f. With the ar rangement of a plurality of a pair of small holes on torque transmitting plate 5c and a plurality of small holes at regular positions on torque receiving plate 6b, both plates are mated and worked in the same manner as the coupling device shown in FIGS. 12-14. i

In short, a principal object of the present invention has advantages in that it involves economical consumption of compresesd air by using it in proportion to the load and such control can be effected on step-less basis and by perfect automatic action and that the machine stands long use because of simpleness of its control mechanism and non-existence of wearing part due to high speed revolution. In addition, it is an outstanding feature of the present invention that the pneumatic rotative machine can be made reversible by giving it slight modifications.

Having thus described the nature of the invention, what I claim herein is:

1. A pneumatically driven rotating machine, comprising; a rotor having blades thereon, a casing within which said rotor is rotatably mounted with the blades cooperating with the casing for rotation of the rotor when air is directed into the casing against the blades, a driving shaft extending from said rotor, a torque transmitting plate mounted on the driving shaft and having the periphery adjacent the inside of the casing and having at least one cutout portion in the periphery thereof, a driven shaft extending from said casing, a torque receiving plate mounted on said driven shaft adjacent the torque transmitting plate and having the periphery adjacent the inside of the casing and having at least one cutout portion in the periphery thereof adjacent the cutout in said torque transmitting plate, spring means on one of said plates engaged by the other of said plates to form a coupling betwen said plates for transmitting torque between said plates, said casing having an exhaust opening on the other side of said plates from said rotor, and said cutouts being out of alignment when the torque transmitted is near zero and are in alignment when the torque transmitted is a maximum, thereby the air passed through the machine is increased as the torque is increased and decreased as the torque is decreased.

2. r A pneumatically driven machine as claimed in claim 1 in which one of said plates has a projection thereon adjacent the cutout portion thereon for blocking further relative movement of the other plate when the cutout portions are aligned even when there is a further in crease in the torque.

3. A pneumatically driven machine as claimed in claim 1 in which one of said plates has springs thereon and the other plate has projections thereon engaging the corresponding springs on the one plate for stressing the springs as the torque transmitted between the plates increases.

4. A pneumatically driven rotating machine as claimed in claim 1, in which the torque transmitting plate has cutout portions on either side of non-cutout portions, both cutout portions and non-cutout portions being almost equal in peripheral width, with which is mated the torque receiving plate having cutout portions with peripheral width almost equal to said cutout portions, whereby gaps for exhausting can be formed oppositely and thus the machine is made reversible.

5. A pneumatically driven rotating machine as claimed in claim 1, in which the torque receiving plate has cutout portions on either side of non-cutout portions, both cutout portions and non-cutout portions being almost equal in peripheral width, with which is mated the torque transmitting plate having cutout portions with peripheral width almost equal to said cutout portions, whereby gaps for exhausting can be formed oppositely and thus the machine is made reversible.

6. A pneumatically driven rotating machine as claimed in claim 4, in which cutout portions on either side of non-cutout portions are replaced by holes.

7. A pneumatically driven rotating machine as claimed in claim 5, in which cutout portions on either side of non-cutout portions are replaced by holes.

References Cited UNITED STATES PATENTS 1,008,781 11/1911 Born.

1,878,747 9/1932 Youngblood.

2,080,973 5/1937 Speth 91-59 X 2,825,531 3/1958 Holt.

2,893,688 7/1959 Shada 253-3 3,049,098 8/ 1962 Inoue 91-59 3,305,214 2/ 1967 Kennedy 253- EVERETTE A. POWELL, JR., Primary Examiner.

US. Cl. X.R.

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3578872 *Nov 14, 1969May 18, 1971Air Instr IncSpeed and torque control for surgical turbine
US3728052 *Apr 16, 1971Apr 17, 1973Dotko IncAir operated tool
US4278427 *Sep 7, 1979Jul 14, 1981Kaltenbach & Voight Gmbh & Co.Compressed-air dental motor
US5667383 *Aug 23, 1994Sep 16, 1997Denticator International, Inc.Disposable dental prophylaxis handpiece
US5697773 *Aug 23, 1994Dec 16, 1997Denticator International, Inc.Rotary fluid reaction device having hinged vanes
US5743718 *Jun 7, 1995Apr 28, 1998Denticator International, Inc.Compressed air driven disposable hand tool having a rotor with radially moving vanes
EP1657408A1 *May 2, 2001May 17, 2006Mitaka Kohki Co., Ltd.Air motor suitable for use with an MRI
WO1996039982A1 *Jun 5, 1996Dec 19, 1996Denticator Int IncCompressed air driven disposable hand tool
Classifications
U.S. Classification415/36, 91/59, 415/904, 415/124.2
International ClassificationF01D15/06
Cooperative ClassificationF01D15/06, Y10S415/904
European ClassificationF01D15/06