US2380457A - Automatic control means - Google Patents

Description

July I L. MAXSON AUTOMATIC CONTRO L MEANS Filed Dec. 30, 1941 4 Sheets-Sheet 3 July 31, 1945. A so I 2,380,457

AUTOMATIC CONTROL MEANS Fi led Dec. 50, 1941 4 Sheets-Sheet 4 Patented July 3l, 1945 AUTOMATIC CONTROL MEANS Louis A. Maxson, Claremont, N. H., assignor to Sullivan Machinery Company, a corporation of Massachusetts Application December 30, 1941, Serial No. 424,971

14' Claims.

This invention relates to automatic controlling means for automatically fed work performing devices and especially, though not exclusively, to

automatically controlled drilling apparatus, and still more particularly, from one aspect, to improved feed control means for drilling apparatus of the high speed rotary type. c

It is an object of this invention to provide an improved automatic feed controlling means. It is another object to provide an improved automatically controlled power-fed work performing device. Another object of this invention is to provide improved feed control means for a drilling apparatus of the rotary type. Still another object is to provide improved means responsive to the torque on a drill or other tool rotating shaft for controlling the supply of pressure fluid to pressure fluid operated feeding means for the apparatus of which such shaft is a part. Still a further object-is to provide improved means for yieldably connecting the drive shaft of a rotary type drill or other tool driving motor to a drill or other tool, and operative at predetermined loads on the drill or other tool shaft for cutting oil the supply'of pressure fluid to pressure responsive feeding means. Another object is to provide improved means connected between the power shaft of a rotary type drill or other tool operating motor and a drill shaft for controlling a torque-controlled valve in a pressure fluid supply line of a ressure operated feeding device. Still a further object is to provide an improved hydraulically operated, torque responsive, feed control mechanism. Other objects and advantages of this invention will appear in the course of the following description.

In the accompanying drawings there is shown for purposes of illustration one form which the invention may assume in practice.

' In these drawings:

Fig.1 is a side elevational view of a drilling apparatus in which an illustrative form of the improved feed control means is incorporated.

Figs. 2 and 3, when taken together, constitute an enlarged view in central, longitudinal, vertical section through the drilling apparatus shown in Fig. 1.

Fig. 4 is an enlarged fragmentary view taken in the plane of Fig. 2 and showing details of construction.

Fig-5 is an enlarged cross sectional view taken on the plane of the line 5-5 of Fig. 2.

i 8 is an enlarged cross sectional view taken on the plane of the line 8-4 of Fig. 2.

Fig. 'I is a detail sectional view taken on the planes of the line '|l of Fig. 9.

Fig. 8 is a fragmentary horizontal sectional view taken on the plane of'the line 8-8 of Fig. 6.

Fig. 9 is an enlarged vertical cross sectional view taken on the line 0-9 of F18. 2.

Fig. 10 is a fragmentary horizontal sectional view taken on the line lO-ll of Fig. 9.

Fig. 11 is a detail sectional view showing portions'of the forward feed passages.

In this illustrative embodiment of the invention, which shows the latter incorporated in a drill operating mechanism, a drilling mechanism, generally designated l, of the high speed, rotary type adapted for use with core or plug-type bits, generally comprises drill bit rotation means I,

drill bit feeding means 3, a control head 4 con- I taining improved feed control means, generally designated I. and drill guiding and supp tin means, generally designated 8. This drill mechanism, except for the operative connections between the drilling motorand the drilling implement and the feed control means, is similar to that shown and describedin a copending application of Win W. Paget, Serial No. 268,792, now matured into Patent No. 2,288,541, which is also owned by the assignee of this present application.

The drill supporting and guiding means 6 comprises a trunnion member I having a swivel plate 8 adapted to be clamped in the saddle mounting of a mine column or any other suitable support. Extending longitudinally through the trunnion member is a bore which receives a cylindrical tube '8 having its ends fixed .asu-pport member II and providing a pivotal mounting for the support member so that the latter may be swung laterally to move thcdrill into a position at one side of the drill hole. Carried by'the support member II is a plunger ii adapted to be received within an opening I 2 in the trunnion member for locking the support member in its upright drilling position. Extending longitudinally through the support member is a bore which slidingly receives and guides a feed cylinder II of the feeding means I.

The feed cylinder lt'contains a reciprocable feed piston it having a tubular piston rod is extending forwardly through the cylinder and having fixed to its forward end a plate It, as

shown in Fig. 2. The feed cylinder I! has front and rear heads i1 and it, the former carrying a packing I! sealingly engaging the exterior periphery of the piston rod and the latter head being detachably secured, as by screws, to the rear end of the feed cylinder. The front and rear cylinder heads I1 and I! have depending bosses provided with bores in which is rotatably fixed against axial displacement with respect to the feed cylinder by a split ring 23 seated in external and internal grooves on the tube-20 and a detachable end plate 24 respectively, the latter secured to the front head ll. of the feed cylinder II. The tube 20 projects rearwardly through the rear head boss and has secured thereto a handle 25 by means of which the tube may be manually rotated to feed the cylinder l3 rela tive to the support member".

Secured in any suitable manner to the plate I! is a cylindrically shaped housing 2!, the housing and the plate cooperating to form the control head 4 and providing a chamber 29 within which the improved torque transmitting and control means are located. Formed in the wall of the housing 28.18 a bore containing a tube 3| which shown. The tube ii is fixed within the basin the housing and has a sliding flt with the walls of the tube to hold the feed cylinder against:

electric motor having a cylindrical motor cas- 7 ing 3 8'provided with front and rear heads 31 and 38, the motor parts being held in assembled relation and secured to the housing 28 by tie bolts 3!. The motor has a usual field .40 and an armature rotor 4|, the latter being secured to a tubular shaft 42 jou'rnaled in bearings a suitably supported by the front and rear motor heads The shaft 42 extends through the rear motor head into the chamber "as shown in Fig. 2. Extending, through the tubular shaft 42 is a shaft 4| carrying a chuck 46 at'its forward end for receiving a drill rod and having its rear end extending into the chamber 29 where it is operatively connected, through means more fully to be described. to the tubular shaft 42. As-will be clear'from the later description, the shaft 45 is rotatable through a small angle relative to the shaft 42, and it is held in any suitable way against longitudinal movement relative to shaft 42, as by a thrust bearing 41. .Electrical energy may be conducted to the windings of the-motor from any convenient source through a conventional conductor plug mounted on the motor casing. as shown in Fig. 1.

The means for supplying fluid, preferably liquid under pressure, to the fluid actuated feeding means I comprises a liquid supply chamber ll formed in the housing 2|, and liquid may be conducted to this chamber through a strainer 8| from a supply conduit l2. Also formed in the housing 28 is a longitudinal bore 53 having arranged therein a ported valve bushing 54 in which a control valve BI is reciprocably mounted. This-valve is of the sliding spool type and is operated by a valve adjusting screw it engaging a stationary non-rotatable nut 51 formed within the guide tube 3|. The screw N is rigidly secured to an operating rod 58 which has a sliding but non-rotatable telescopic engagement with an operating rod 80. The rod 89 extends rearwardly within the tubular feed screw, and has secured to its rear end a control handle I. It will be seen that by rotating the handle II, the control valve is may be moved longitudinally within the valve bushing bore through the rotatable screw ll engaging the non-rotatable nut II, and by the provision of the telescopically arranged rods the valve may be operated irrespective of the position of the control head relative to the trunnion support. Communicating with the forward end of the bore of the valve bushing is an exhaust chamber '2 connected to an exhaust port 82, and communicating with the bore of the bushing at its rear end is a chamber '4 connected to the chamber 62 through grooves 88 and 8' extending along the outer surface of the valve bushing. The supply chamber I0 is connected through a port slot CI in the valve bushing to the interior of the latter, and formed in the valve bushing at opposite sides of the port I. are ports 60 and II communicating, respectively, with forward and reverse feed passages to be described. The port It opens into a groove ll communicating with a passage 14. as shown in Figs. 7 and 8, and the passage "is connected. mt a torque-controlled valve means, generally'designated It, to a passage ll (Fig. 11) which into a liquid con-. ducting tube 11 extending longitudinally through the tubular piston rod II and o i through the feed piston l4 into the bore of the feed cylinder II at the rear of the piston. The port ll opens into a passage It in the control head 4, as shown in Figs. 2 and 4. and the passage ll communicates with the interior of the tubular piston rod ii at its forward end. Extending radially through the-tubular piston rod adiacentthe pistonl4, are ports II for conducting liquid from the interior'of the piston rod to the bore of the feed cylinder I! at the forward side of the feed piston. When the control valve 55 is moved to its rearward position, as shown in Fig. 4, liquid isven'ted from the forward feed passages through the port 88 to the chamber 62 and the exhaust port 63. At the same time, the liquid supply chamber 50 is connected through the port It and a groove '2 on the control valve to the passage so that liquid is supplied under pressure to the feed cylinder at the forward side of the feed piston for moving the latter toward the rear end of the feed cylinder. When the valve II is moved to'its extreme forward position, the reverse feed passages are vented through the port I. to the chamber 84 which is connected to exhaust through the grooves I, It, the chamber 82 and the port 63. The supply chamber 50 is connected at this time through the port II to ports 83 opening into a chamber .4 in the control valve, and the chamber I4 is connected through ports 8! to the port I! communicating with the forward feed passages which conduct liquid, under control of the torque-controlled valve II, to the feed cylinder at the rear side of the feed piston for eflecting movement of the latter in a forward direction.

The torque-controlled valve Ii comprises, as shown in Fig. 9, a valve sleeve is arranged within a transverse bore 4! in the housing 20 of the control head 4. Extending longitudinally through the valve sleeve is a valve member ll having a beveled shoulder ll adapted to cooperate with a beveled valve seat 92 on the sleeve. Formed in the valve sleeve at opposite sides of the valve seat are bores s: and .4, the bore l3 communicating through a port I! with the passage 14, and the bore 94 communicating through a port it with the passage II. when the valve member I.

the quadrantal portions I04.

is moved to its 'unseated position, as in Fig. 9, the forward feed passages I4 and I6 are connected in communication with each other through the port 35, the bores 03 and 04, and the port 36. With the valve member in its seated position, communication between the passages I4 and I6 is cut oil, and forward feed is immediately stopped since there is no expansion of the liquid valve member toward its unseated position.

Improved means, generally designated 5, is provided for transmitting the torque from the rotor shaft 42 to the shaft 45 and for moving the valve member 90 to its seated position when the torque transmitted from the rotor shaft 42 to the shaft 45 exceeds a predetermined amount. This means comprises, as shown in Figs. 2, 5 and 6, a member I03 suitably splined or keyed to the rear end of the tubular shaft 42 and herein having diametrically opposite quadrantal portions I04 projecting outwardly at opposite sides of the shaft. Keyed to the rear end of the shaft 45 is a member I05 having diametrically opposite quadrantal portions I06 extending outwardly in opposite directions from the shaft and fitting freely between The portions I04 and I06 are so proportioned as to provide clearances-I'I between them whereby a slight relative rotation between th shafts 42 and 45 is permitted. Force transmitting means actuated by the relative movements between the portions I04 and I06 upon the transmission of driving forces from one to the other may assume various forms and herein I have shown for purposes of illustration a hydraulic system. Formed in certain of the adjacent faces of the quadrantal portions I04 and I06, as shown in Fig. 6, are recesses I08 and I00 opening into each other other and cooperating to form chambers receiving hollow yieldable elements or bellows IIO whose interiors communicate with passages III formed in the quadrantal portions I06. The passages III are connected, as shown in Fig. 5, through radial passages I'I3 in the shaft 45 to a passage I I4 extending axially within the shaft. Arranged in a recess H in the rear end of the shaft 45, is a yieldable element or bellows II6 connected in communication with the passage II4. It will be understood that the entire driving torque may be transmitted through the fluid system formed by the interconnected bellows, but it may be desirable to provide suitable means, such as springs S received in pockets formed in the same faces of the members I 04 and I06 that receive the bellows IIO, to absorb a part of the driving torque,

- both arrangements being within the contemplation of my invention. The springs may be of such strength and length as normally-to be received full length (fully extended) within the pockets in the absence of driving torque.

Mechanism actuated by the bellows II6 for controlling the feed may now be described. Formed on the plate I6 and projecting forwardly into the housing 28, as shown in Figs. 2 and 10, are spaced guide members I" providing longitudinally extending guide surfaces II6 for a slid-- ing cam element H9. The guide members Ill and the guide surfaces II3 are so arranged as to support the cam element H9 in axial alinement with the shaft 45 for longitudinal sliding movement relative to the latter. Extending verment H3, is a lever I23 projecting downwardly through the opening I20 in the cam element and having a forked lower end fitting within a groove" 7 I23 in the sleeve 30 threaded on the valve member 00. It will be noted that the pivotal connec- .tion for the lever I23 is such as to provide for a swinging of the lever transversely of the housing, and the lever is continuously held against the cam'surface I2I by the action of the spring I 00 urging the valve member 30 toward itsunseated position. The parts of the control means are so related that, for normal loads on the drill motor, the valve member is held in its open position, and the camelement is moved forwardly by the action of the lever I23 on its cam surface I2I, to engage the rear end of the bellows I I6 through a friction reducing element, such as a ball I24. The interior of the bellows H0 and H6, and the passages I I I, H3 and I I4 provide a closed system which is filled with a fluid, preferably a liquid whereby operating pressures are transmitted to one part of the system when another part of the system reacts to pressures to be controlled.

When the load on the bit rotating means exceeds a predetermined amount, 1. e. if the resistance to drill bit rotation becomes excessive, the shaft 45 is caused to lag behind-the shaft 42 and the quadrantal portions I 04 and I06 are moved relative to each other in a direction to compress the bellows H0. The gaseous fluid or liquid contained within the bellows H0 is forced into the passages III, H3, H4, and the bellows H6, increasing the pressure therein and causing the bellows II6 to expand, moving ahead of it the cam element II9. As the cam element is forced rearwardly, the cam surface I2I acts against the lever I23 forcing the latter in a direction to move the valve member towards its seated position against the tension of the spring I00 and reduce or completely cut oil the supply of liquid to the feed cylinder.

In order to prevent an overheating of the bit during drilling, there are provided means .for delivering a cooling liquid to the drill hole. This means comprises a passage I25 opening into the liquid supply chamber, as shown in Fig. 5, and conducting liquid past a manually operated valve I26 to a passage I2'I extending longitudinally through the motor casing. The passage I2! is connected, as shown in Fig. 2, through a radial passage I28, formed in a collar I29 surrounding the shaft 45, to a groove I30 communicating with radial passages I3I and an axial passage I32 formed in the shaft 45. The passage I32 extends through the forward end of the shaft 45 and delivers the cooling liquid to a passage extending longitudinally through the drill shaft in a usual manner. Surrounding the shaft 45 at opposite sides of the groove I 30, are packing leathers I35 held firmly in engagement with the periphery of the shaft to prevent the escape of cooling liquid along the shaft to the bearings 43, and to the interior of a fan housing I36 containing a fan I31 which is driven by the shaft 45 for forcing cooling air through the motor casing.

Returning to the specific improvements disclosed in this application, it will be observed that with the use of springs such as those shown at S a large part of the torque may be transmitted through the springs and by providing springs of appropriate characteristics the pressure within the closed fluid system necessary to effect the desired controls will not need to be so high as if the spring I had to be made strong enough towi-thstand in the necessary manner the pressure which would build up in the bellows if the full driving force had to be transmittedthrough the latter. It will be observed, however, that at least in part the fluid system which controls the feed serves to transmit the driving torque, in the speciflc structure shown in the drawings, and with appropriately proportioned and adequately strong bellows H0, H6 and springlllil the entire driving load my be carried through the hydraulic system, and this is within the contemplation of my invention.

As a result of this invention it will be noted that there is provided an improved drilling apparatus of the rotary type. It will be noted that there is also provided improved means for controlling the feeding of the drill, the control means being operative at a predetermined torque on the drill bit for cutting oif the supply of operating fluid to fluid actuated feeding means for the drill. And there is provided an improved driving and feed controlling means adapted to the feeding and driving of a very wide variety of mechanisms.

ratus will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and. desire to secure by Letters Patent is:

1. In a drilling apparatus, in combination, a motor for rotating a drill bit, driving connections between said motor and the drill bit including a driven shaft and a fluid containing system yield-' ingly connecting said motor to said shaft, power operated feeding means for the drill bit, and

means for controlling said feeding means in accordance with the load on said motor, said controlling means including means operatively connected to said fluid containing system.

2. In a drilling apparatus, in combination, a

taining system yieldingly connecting said power shaft to said driven shaft, fluid actuated feeding means for the drill bit, and means for controlling the supply of fluid to said feeding means in accordance with the resistance to drill bit rotation, said controlling means including means actuated by said fluid containing system on relative rotation between said shafts.

3. In a drilling apparatus, in combination, a motor for rotating a drill bit, said motor having a power shaft, driving connections between said power shaft and the drill bit including a driven shaft, and means including a closed fluid containing system yieldingiy connecting said power shaft to said driven shaft, fluid actuated feeding means for the drill bit, and means for controlling the supply of fluid to said feeding means in accordance with the load changes on said motor, said controlling means comprising a torque controlled valve, and means controlled by said fluid containing system on relative rotation between Other advantages of the improved drilling appa- Ill said power shaft and said driven shaft for actuating said valve.

4. In a drilling apparatus, in combination, a motor for rotating a drill bit, said motor havin a power shaft,driving connections between said power shaft and the drill bit including a driven shaft, members flxed to said shafts and having projecting portions interfltting freely with each other, yielding chamber providing elements arranged between said projecting portions, a yielding chamber providing element arranged at an end of one of said shafts, passage means connecting said chamber providing elements, said chamber providing elements and said passage means forming a closed system for containing a fluid which acts to expand one of said elements when another is compressed, fluid actuated feeding means for the drill bit, and means responsive to the action of one of said yielding chamber providing elements for controlling the supply of fluid to said feeding means.

5. In a drilling apparatus, in combination, a motor for rotating a drill bit, said motor having a power shaft, driving connections between said power shaft and the drill bit including a driven shaft, members fixed to said shafts and having projecting portions interfltting freely with each other, yielding chamber providing elements arranged between said projecting portions, a yielding chamber providing element arranged at an end of one of said shafts, passage means connecting said chamber providing elements, said chamber providing elements and said passage means forming a closed system for containing a fluid which acts to expand one of said elements when another is compressed, fluid actuated feeding means for the drill bit, valve means for controlling the supply of fluid to said feeding means, and means actuated by one of said yielding chamber providing elements for controlling said valve means.

6. In a drilling apparatus, in combination, a motor for rotating a drill bit, said motor having a power shaft, driving connections between said power shaft and the drill bit including a driven shaft, members flxed' to said shafts and having projecting portions interfltting freely with each other, yielding chamber providing elements arranged between said projecting portions, a yielding chamber providing element arranged at an end of one of said shafts, passage means connecting said chamber providing elements, said chamber providing elements and said passage means forming a closed system for containing a fluid which acts to expand one of said elements when another is compressed, fluid actuated feeding means for the drill bit, valve means for controlling the supply of fluid to said feeding means,

and means actuated by one of said yielding chamber providing elements when others of said elements are compressed due to relative rotation of said shafts for effecting closure of said valve means.

7. In a drilling apparatus, in combination, a motor for rotating a drill bit, said motor having a tubular power shaft, driving connections between said power shaft and the drill bit including a driven shaft extending through said tubular power shaft, a member fixed to said power shaft and having radially projecting portions, a member fixed to said driven shaft and having radially projecting portions extending between the projecting portions on said member flxed to said power shaft, yielding chamber providing elements arranged between said projecting portions, a

yielding chamber providing element arranged at one end of said driven shaft, passage means connecting said chamber providing elements, said chamber providing elements and said passage means forming a closed system for containing a fluid through which energy may be transmitted, fluid actuated feeding means for the drill bit, and means actuated by one of said chamber providing elements when others are compressed on relative rotation of said shafts for controlling the supply of fluid to said feeding means.

8. In a drilling apparatus, in combination, a motor. for rotating a drill bit, said motor having a tubular power shaft, driving connections between said power shaft and the drill bit including a driven shaft extending through said tubular power shaft, a member fixed to said power shaft and having radially projecting portions, a member fixed to said driven shaft and having radially projecting portions extending between the projecting portions on said member fixed to said power shaft, yielding chamber providing elements arranged between said projecting portions, a yielding chamber providing element arranged at one end of said driven shaft, passage means connecting said chamber providing elements, said chamber providing elements and said passage means forming a closed system for containing a chamber providing element at the end of said driven shaft when fluid is forced thereto by compression of said chamber providing elements between said projections for closing said. valve means.

9. In combination, an implement, a shaft connected in driving relation with said implement, a motor, means including a fluid containing system connecting said motor to said shaft, said fluid containing system so constructed and so related to said motor and said shaft that said fluid is placed under pressure when said motor exerts a torque on said shaft, power operated means for feeding said implement, and means responsive to the pressure changes in said fluid for controlling the delivery of power to said feeding means.

10. In combination, in a controlling apparatus, an expansible chamber forming means, another expansible chamber forming means, means connecting said expansible chamber forming means together to form a closed, self-contained fluid system, one of said expansible chamber forming means varying in volume in accordance with the Pressures acting thereon and causing fluid to flow relative to the other expansible chamber forming means for efiecting changes in the volume of the latter, means for exerting on one of said expansible chamber forming means a pressure varying with a load to be controlled, and means actuated by changes in volume of the other of said expansible chamber forming means for effecting a control of such load.

11. In combination, a motor for rotating an implement, power operated means for feeding said motor, and means for connecting said motor in driving relation with the implement to be rotated thereby and for controlling the feeding force exerted by said feeding means including a closed liquid system having movable walls, one of said walls subjected to a pressure varying with the resistance to implement rotation and another of said walls exerting a corresponding pressure to control the delivery of power to said feeding means.

12. In combination, an implement, a motor for driving said implement, said driwng motor having a power shaft, a shaft to be driven by said power shaft and connected to said implement, at least one radial arm on each of said shafts, yieldable means connected between said radial arms for transmitting power from said power shaft to said driven shaft, power operated means for feeding said implement, and means including a system actuated by relative angular movement between said arms for controlling the delivery of power to said feeding means.

13. In combination, power operated means for rotating 9. tool, power operated means for feedin the tool rotated by said first mentioned means longitudinally of its axis, means including a yieldable power transmitting means for yieldingly connecting one of said power operated means to the tool, and means responsive to the yielding of said yieldable connecting means and having pressure fluid operated controlling means for controlling the delivery of power to the other of said power operated means.

14. In combination, power operated means for rotating a tool, power operated means for feeding the tool rotated by said first mentioned means longitudinally of its axis, means including, a closed fluid containing system for yieldingly connecting one of said power operated means to the tool, said fluid containing system so constructed and so related to the one of said power operated means/it connects to the tool that the fluid therein is placed under pressure varying with the power delivered, and means responsive to the pressures of the fluid in said system for controlling the delivery of power to the other of said'power operated means.

LOUIS A. MAXSON.

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