US2320571A - Motor - Google Patents

Description

June 1, 1943. J. c. CURTIS 2,320,571

MOTOR Filed March 15, 1941 l2 sheets-shea 1 Z wm? v ha .mmm a. 1 M M mw QN md Y Sv :MP: Il I n Y mq s. 1| e Wm -n i a 1% ww s -11. mw sam @mmh NN d 1 Mg. WN mw a s @Q S .maw mw mw N N. .Fm HYLN Nw @mbv um QN m. m 0N s; m m s mfm m P l H ,Il mm ow Il... I 1 l| l m UV S mw 1 wm E JE S @NN N N m HD June 1, 1943. J. c. CURTIS 2,320,571

MOTOR Filed March 13, '1941 2 Sheets-SheetZ E l 95 25124571/207: 1o 9b Jaim/a Wm.

9@ www? uw. s mamy MM 95 5725 8/05 /o/' 95 att?! Patented June 1, 1943 MOTOR John C. Curtis, Claremont, N. H., assignor to Sub livan Machinery Company, a corporation of Massachusetts Application March 13, 19M, Serial No. 383,136

6 Claims. (Cl. 121-9) This invention relates to motors, and more particularly to uid actuated motors adapted especially for feeding rock drills relative to their work.

In hammer drills of the type which are adapted to be fed during drilling along suitable guiding and `supporting means, it is found that improved operation may be obtained, at least under certain conditions, by providing reversible feeding means that do not depend on the operation of the drill motor for feeding the drill relative to its Work. With such a yfeeding means there may be obtained a holding of the drill steel firmly against its work; and the full force ofthe drill motor may be delivered to the drill steel.

A positive feeding means for such a drill may desirably Ftake the form of an air motor mounted on the supporting means for the rock -drill and operatively connected to one end of a feed screw for driving the latter and effecting feed, or, selectively, the retraction, of the drill motor along its support. A desirable form of air motor is one in which a plurality of cylinders project radially from a motor casing, perpendicular to the crankshaft of the motor. Passages in the motor casing leading to the bores of the cylinders may, according to the present invention, be successively connected to supply and exhaust by valve means connected to rotate with the crankshaft and having passages communicable with the first mentioned passages and opening to points of supply and exhaust. the arrangement outlined, while preferred, is not requisite, and that the invention is capable of wide variation Within the scope of the appended claims. Y

It is an object of this invention to provide an improved motor. It is another object to provide an improved motor especially adapted for a motor operated feed. It is still another object to provide an improved reversible motor especially adapted for feeding a rock drill relative to its work. Still another object is to provide an improved air motor adapted to be connected to va feed screw and to drive the .latter for feeding a drill motor relative to its work. Yet another object is to provide an improved multi-cylinder air motor having improved means for successively supplying pressure fluid to and venting preS- sure duid from its cylinders. Another object is to provide, in an improved air motor, improved means rotating with the power shaft of the motor for successively supplying pressure fluid to and venting pressure fluid from the motor cylin- It will be appreciated that ders. ther objects and advantages of my invention will hereinafter more fully appear.

In the accompanying drawings, in` which for purposes of illustration one embodiment and a modification of the invention are shown,

Fig. 1 isa side elevation, with parts broken away, of a slidably supported drill in which an illustrative form of the invention is incorporated.

Fig. 2 is an enlarged View in central Vertical longitudinal section, through the feeding mechanism of the apparatus shown in Fig. 1.

Fig. 3 is an enlarged cross sectional view taken on the planes of the line 3-3 of Fig. 1.

Fig. 4 is an enlarged longitudinal sectional view taken on the planes of the line 4 4 of Fig. 3.

Fig. 5 is a detail ysectional view taken on the plane of the line 5-5 of Fig. 4. i

Fig. 6 is a detail sectional View through the control valve taken on the plane Iof the line S-S of Fig. 4. v

Fig. 7 is a cross sectional View of the feed motor taken on the plane of the line 'l-'l of Fig. 4.

Fig. 8 is a cross sectional view of the feed motor taken on the plane of the line 8 8 of Fig. 4.

Fig. 9 i-s a cross sectional View of the feed motor taken on the plane of the line 9-9 of Fig. 4.

Fig. 10 is a detail longitudinal 'sectional view of the feed'motor taken on the plane of the line Eil-Iii of Fig. 9.

Fig. l1 is a fragmentary sectional view'taken on the plane 0f Fig. 2, showing a modification of the invention. l

In Fig. 1 of the drawings there is shown a hammer motor, generally designated l, that is adapted to actuate percussively a drill steel 2, and which is slidably guided ina shell 3 having a trunnion support 4. At the rear end of the motor is a depending ylug 5 in which a feed nut 6 is received, the feed nut being clamped in position by means of a washer l and a holding nut B at the rearward end of the lug 5, and the feed nut having, at its forward end, a head 9 spaced by another washer i9 from the lug 5. The feed nut is threadedly interengaged with a feed screw i2 extending longitudinally of the shell 3. The feed screw is journaled at its forward end in a bearing I4 supported by the shell 3. The rearward end of the feed screw extends through an opening i5 'in a transverse member I6 supported by a rearward extension l1 of the shell, and fixed to the rear end of the feed screwnis an enlarged circular portion l which is journal'ed in a ball bearing i9 supported by a sleevelike member 20. A reversible motor, generally designated 22, o-f an improved construction, is clamped against the sleevelike member 20, and the motor is operatively connected to the feed screw |2, for driving the latter, as will shortly be described.

The motor 22, as herein shown, comprises a generally cylindrical casing 25 having radially projecting portions 26 providing openings 21 within which cylinder members 28 are threaded and supported so that the axes of the cylinder members extend radially from the longitudinal axis of the motor casing. The cylinder members are herein four in number and are arranged in pairs so that the cylinder members of each pair are diametrically opposite each other and have their axes lying in a common plane. The alined axes of one pair of cylinder members lie in a line perpendicular to a line parallel to the line in which the axes of the other pair are disposed; and the planes including the axes of the pairs are parallel to a common plane and spaced a short distance apart. The motor casing is herein arranged with its longitudinal axis in alinement with the axis of rotation of the feed screw, and its forward end ts over a rearwardly extending sleeve portion 29 upon the sleevelike member 20. 'I'he motor casing 25, the sleevelike member 20, the transverse member I6, and the rearward extension |1 of the shell 3 are provided with lugs 3|), 3|, 32 and 33, respectively, these lugs having openings through which bolts 34 extend for clamping the lugs together so that the motor is rigidly supported at the rear end of the shell. Attached to the rear end of the motor casing, as by screws 35, is a cover plate 36 having openings 31 and 38 connecting the interior of the casing to atmosphere.

The cylinder members 28 have bores 40 which are closed at their outer ends and which open at their inner ends into the interior of the motor casing; and received in the cylinder bores are pistons 4| secured integrally in pairs by scotch yoke structures 42 and 43. The yokes have slots 44a-nd 45, respectively, arranged in right angle relation to each other, and received in the slots is a crank pin 46 surrounded by a sleeve 41, the crank pin being fixed to a crank disc 48 formed on the end of a crankshaft 50 extending axially of the motor casing. The crankshaft is journaled in bearings and 52 mounted Wtihin the sleeve portion 29 and the motor casing, respectively, and the forward end of the crankshaft is suitably connected, herein through a suitable tongue and slot connection 53, to the rear end of the feed screw |2 to drive the latter.

Means are provided for successively supplying pressure fluid to and venting pressure fluid from the cylinder bores 40 to effect a reciprocation of the pistons for driving the crankshaft in one direction or the other. The fluid supply means includes passages 55 and 56 in the motor casing, opening at their inner ends into annular grooves 51 and 58, respectively, formed in the inner periphery of the casing, and opening at their outer ends into a valve receiving bore 59 formed in a thickened Wall portion 60 of the motor casing,A as shown in Figs. 3 and 4. When pressure fluid is supplied to the passage 55 and exhausted through the passage 56, the motor will operate, as will later be more fully explained, to turn the feed screw in a direction to effect a forward feed of the hammer motor; and when pressure fluid is supplied to the passage 56 and exhausted through the passage 55, the direction of rotation of the feed screw will be reversed to effect a retraction of the hammer motor. Arranged in the valve receiving bore 59 is a valve mechanism, gen- 75 erally designated 62, similar to that shown and described in an application of one Frank E. Sinclair, Serial No. 346,938, filed July 23, 1940, now matured into Patent No. 2,312,366, patented March 2, 1943. The valve mechanism 62 includes a valve 63 arranged in the bore 59 and having a valve stem 64 extending through an opening 65 in the rear end of the motor casing. Attached to the outer end of the valve stem 64 is an operating handle 66. The forward end of the bore 59 is closed by a head 61 to which a supply connection 68 for operating fluid is attached, as by a coupling 69. Formed in the valve 63 is a bore 10 opening through the end of the valve adjacent the supply connection. A slightly smaller bore 12 in the valve 63 is alined with and opens into the bore 10, and within the bore 12 is a valve 13 having a valve stem 14 extending through a further bore 15 in the valve 63, Fixed to the outer end of the valve stem 14 is a handle 16 by means of which the valve 13 can be rotated. Formed in the valve 13 is a bore 18 opening into the bore 10. 1

On the outer periphery of the valve 63 is a groove communicating with the passage 55 when the valve is rotated to a proper position. A port 8| in the valve 13 opens into a luneshaped groove 82 on the outer periphery of the valve 13 and supplies pressure fluid to a passage 83 in the valve 63 which opens into the groove 8D. By reason of the lune-shaped groove there may be obtained a controlled rate of pressure fluid supply to the passage 55. Formed in the valve 63, adjacent its ends, are peripherally extending grooves 84 and 85, and these grooves are connected by a groove 86 extending longitudinally of the valve. The groove 84 extends, as shown in Fig. 6, somewhat less than half Way around the valve and communicates with the passage 56 in certain positions of the valve 63, as also shown in Fig. 6; and the groove 85, which extends as shown herein somewhat more than half way around the valve, communicates with ports 81 opening into the interior of the crank casing. The supply of pressure fluid to the passage 55 may be reduced, if desired, by restricted ly venting groove 80 through ports 88 and 89 in the valve 63 and a lune-shaped groove 90 in the valve 13. The now of pressure fluid to the passage 55 may be increased by rotating the valve 63 to place an enlarged port 92 in the valve 63 in communication with the passage 55. To supply pressure fluid to the passage 56, there is provided a port 93 in the valve 63, as shown in Fig. 6. A longitudinally extending groove 94 in the valve 63 connects the passage 55 to exhaust through ports 81 when the valve is in a position to supply pressure fluid to passage 56 through port 93. n

The improved means for distributing pressure fluid to the cylinder bores 40 from the passages 55, 56 and the grooves 51, 58 herein includes passages 95 formed in the motor casing, as shown in Figs. 4 and 9, and opening at their inner ends into segmental grooves 96 formed in the inner periphery of the casing. The passages 95 communicate with annular grooves 91 formed in the motor casing around the cylinder members 28, and multiple passages 98 connect the annular grooves to the outer ends of the cylinder bores 49. Arranged within the motor casing and having a close running t with its inner surface is a sleeve-shaped valve member |00, the latter being keyed to the crankshaft 50 for rotation therewith, lExtending longitudinally within the sleeve-shaped member are several bores |I, |0|. Some of these, |0| extending completely through member |00, are for reducing its Weight, and others, later mentioned, and closed at both ends, are employed for successively connecting the passages 55 and 56 with the passages 95 as the sleeve member is rotated. A groove |03 on the outer periphery of the sleeve-shaped valve member |00, and in the same transverse plane with the passage 55, connects the passage 55 through the annular groove 51 With one of the bores, numbered |04, in the valve member. the transverse plane with the passage 56 there is provided, in the sleeve-shaped valve member |00, a groove opening into another of the bores, numbered |06, in the valve member. The bores |04 and |06 are spaced angularly from each other approximately 135. In the transverse plane with the passages 95 there are provided segmental grooves |08 and |09 in the valve member, opening into the bores |04 and |06, respectively. The grooves 96 in the motor casing and the grooves |08 and |09 in the valve member are so formed that the forward end of the one of the two latter grooves to which pressure fluid is supplied, will be placed in communication with one of the grooves 95 just as the piston in the cylinder supplied by that groove passes its outermost point, and the rear end of the groove passes beyond the groove 96 a little before the piston reaches the innermost point in its stroke. At times two adjacent grooves 96 are connected by either the groove |58 or |00 to supply pressure fluid to or vent pressure fluid from two of the motor cylinders simultaneously. The bores |04 and |06 extend through only part of the length of the sleeve-shaped valve member |00 and are closed at their forward ends by plugs and ||2, as shown in Figs. 4 and 10. Extending longitudinally through the crankshaft is a passage I3, opening through the rear end of the crankshaft into the interior of the motor casing, and passages H4, extending radially through the valve member |00 in the same transverse plane with the passages 95, open into a radially extending passage ||5 in the crankshaft that communicates with the passage H3. The passages ||4 open through the cuter periphery of the valve member |00 at points spaced approximately midway between the bores |04 and |06, and are placed in communication with the grooves 96 to vent pressure fluid from the cylinder bores shortly after the supply of pressure fluid to them has been cut oil.

The method of operation of the mechanism described is as follows. Assuming that the parts are in the positions shown in the drawings, pressure fluid will flow from the supply connection 68 into the bore 10 in the valve 63, and will pass from there into the bore 18 in the valve 13, then through port 8|, the lune-shaped groove 02 and the passage 83 into the groove 00 where it is conducted to the passage 55 in the motor casing. The passage 56 in the casing is connected through the peripherally extending groove 84, the groove 86 and the groove 05 to the ports 81 opening into the interior of the motor casing, and any pressure fluid entering the interior of the motor casing escapes to atmosphere through ports 38 and 31 in the rear cover plate 36.

Pressure fluid entering the passage 55 flows into the annular groove 51, and is supplied from there through the groove |03 to the bore Inv |04 where it is conducted to the segmental groove |08. In the position of the sleeve-shaped valve member shown, pressure fluid will be supplied yfrom the groove |08 to two of the grooves 96, one supplying fluid to the passage leading to the cylinder bore on the near side of the motor, and the other supplying fluid to the passage 95 leading to the cylinder at the top of the motor. As shown in Fig. 3, the piston in the near cylinder is approaching the innermost point in its stroke, and the piston in the top cylinder is near, but just past, its outermost point, so that it is starting inwardly again. Pressure fluid acting on the right-hand horizontal piston is still forcing the pistons lying in the horizontal plane to the left, and is just starting to force the pistons lying in the vertical plane downwardly. The cylinder bore at ,the left in Fig. 3 is vented through the passages 98, groove 91, passage 95, grooves 96 and |09, bore |06 in the valve member |00, groove |05, annular groove 58, and passage 56 connected to atmosphere through the valve mechanism 62 as explained above. The cylinder bore at the bottom of the motor is connected to atmosphere through passages ||4, ||5 and ||3 leading to the interior of the motor casing through the crankshaft. The yokes 42 and 43 connecting the motor pistons will act on the crank pin 46 to rotate the crankshaft and the feed screw |2 in a counterclockwise direction, as viewed in Fig. 3, and effect a forward feed of the hammer motor l.

As the valve member |00 is rotated with the crankshaft, the groove |08 passes beyond the groove 96 communicating with the near cylinder, and the passages I4 are moved into communication with this groove 96 to vent pressure fluid Vfrom the cylinder just about as its piston starts to travel outward. When the passages M are moved out of communication with the bottom cylinder, the segmental groove |09 in the valve |00 will be moved into communication with the bottom groove 96 to vent the bottom cylinder until the piston reaches its outermost point. Shortly after the groove |09 is moved out of communication with one of the grooves 96, the groove |08 is moved into communication with that groove to supply pressure fluid again to one of the motor cylinders.

If the valve 63 is rotated to supply pressure fluid through port 93 to the passage 56, then the groove 94 in the valve 63 will be placed in communication with passage 55 and connect the latter passage to atmosphere through the ports B1 opening into the interior of the motor casing. Pressure fluid will flow through passage 56, annular groove 58, groove |05 and bore |06 to the segmental groove |09. The segmental groove |09 will be connected to atmosphere through bore |04, groove |03, annular groove 51, passage 55 and the control valve mechanism. The supply of pressure fluid to the motor cylinders from the groove |09, and the venting of pressure fluid from the motor cylinders to the groove |08 will be such as to cause a rotation of the motor crankshaft and the feed screw in a clockwise direction, as viewed in Fig. 3, and effecta retraction of the hammer motor,

The supply of pressure fluid to effect a retraction of the hammer motor will be such as to cause the motor 22 to operate at a high speed. If the hammer motor were permitted to move to the rear into engagement with a stationary abutment, there would be a Wedging action between the feed nut andthe feed screw, and an undesirable shock to the drill motor. Toravoid this, there are provided means, generally designated I8, for cushioning the impact of the drill motor by gradually increasing the load on the feed screw. The means ||8 forms the subject matter for an application of Sinclair, Serial No. 345,795, filed July 16, 1940, now matured into Patent No. 2,316,192, patented April 13, 1943. This means need not be described in detail, and it will suffice to say that it will bring the rearwardly moving parts to rest without jamming, and permit forward feed to be readily initiated. It will be noted that the feed motor is symmetrically arranged with the feed screw, that it applies a smooth torque to the latter, that it is arranged so that its distributing valve rotates coaxially with the feed screw and is arranged between the rear end of the latter and the motor cylinders, and that the discharge of the exhaust fluid from the motor is most conveniently arranged with respect to the apparatus as a whole.

In a modification of the invention shown in Fig. l1, the feed screw I2' is supported adjacent its rear end in bearings |20 carried by the transverse member I6 and by a sleeve member |2I, respectively. An annular groove |22 surrounds the bearings, and lubricant is supplied to the groove through a port |23 in the sleeve member for lubricating the bearings, The rear end of the feed screw extends' a short distance into the motor casing 25 and is provided with longitudinally extending splines |25 which are engaged by similar splines |26 formed within the forward portion of a sleeve valve The valve |00 is like the valve |00 described above except for its connection to the feed screw and for its support in a ball bearing |21 at its forward end. The crankshaft 50 of the motor extends within the sleeve valve |00 and is keyed to the latter by a key |28. It will be seen that the 'crankshaft 50 drives the valve |00', and the latter drives the feed screw through the engagement 0f the splines |25 and |26. Otherwise the modification is like the preferred form.

As a result of this invention there is provided animproved reversible motor, adapted especially for feeding a drill motor along a supporting structure relative to its Work. The motor is of simple design, and is constructed of parts that may be easily assembled and disassembled. It will be observed that the use of such a motor is not limited to the feeding of a rock drill as shown.

While there are in this application specifically described one form anda modification which the invention may assume in practice, it will be understood that this form and modification of the same are shown for purposes of illustration and that the invention may be further 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. A fluid actuated motor comprising, in combination, a cylindrical motor casing, a crankshaft extending axially of said casing, a plurality of cylinders supported by said casing and extending radially from said crankshaft, pistons reciprocable in said cylinders and connected to said crankshaft for driving the latter, passages opening through the inner wall of said motor casing adjacent the rear end of said crankshaft and communicating with the outer ends of said cylinders, a sleeve member rotatable with said crankshaft, separate passages in said sleeve member opening through the outer periphery thereof at points spaced angularly from each other, said separate Ypassages communicating successively with said first mentioned passages on rotation of said sleeve member, and means including passages opening through the inner wall of said motor casing adjacent the forward end of said crankshaft for connecting said separate passages selectively to supply and exhaust.

2. In combination, in a motor, a crankcase. cylinders supported thereby, a crankshaft extending into said crankcase, means for venting the interior of said crankcase to atmosphere, a distributing valve for said motor, and dual exhaust means for said motor including passages both controlled by said valve and one extending through said crankcase and another through said crankshaft into communication with the vented interior of said crankcase.

3. In a motor, in combination, cylinders, pistons in said cylinders, a crankshaft, operative connections between Said pistons and said crankshaft, a casing having therein passageways selectively effective for the supply or exhaust 'of fluid, a valve mounted on said crankshaft, passage means in said valve communicable with said passageways and each alternatively usable as a supply passage and an exhaust passage, a valve chest having passages through which said passage means are connectible successively to said cylinders, other passage means in said valve communicable with said passages, and an exhaust passage in said crankshaft with which said other lpassage means continuously communicate, said passageways when effective for exhaust and said exhaust passage in said crankshaft discharging exhaust fluid to a common space in said casing.

4. In a huid actuated motor, the combination of a motor casing, a plurality of cylinders supported by said casing and extending radially therefrom, a crankshaft extendingA through said casing forwardly from said cylinders, pistons reciprocable in said cylinders and connected to said crankshaft for driving the latter, passages opening through the inner wall of said motor casing adjacent the rear end of saidcrankshaft and communicating with the outer ends of said cylinders, separate passages opening through the in' ner wall of said casing at points spaced along said crankshaft adjacent the forward end of the latter, a sleeve member rotatable with said crankshaft, passages in said sleeve member opening through the outer periphery thereof at points spaced angularly from each other, said last mentioned passages communicating successively with said first mentioned passages and each communicating continuously with a different one of said separate passages throughout rotation of said sleeve member, and means for connecting said separate passages selectively to supply and exhaust.

5. In a fluid actuated motor, the combination of a motor casing, a plurality of cylinders supported by said casing and extending radially therefrom, a crankshaft extending through said casing forwardly from said cylinders, pistons reciprocable in said cylinders and connected to said crankshaft for driving the latter, passages opening through the inner wall of said motor casing adjacent the rear end of said Acrankshaft and communicating with the outer ends of said cylinders, separate passages, selectively operative as uid supply and exhaust passages, opening through the inner Wall of said casing at points spaced along said crankshaft adjacent the `forward end of the latter, a sleeve member rotatable with said crankshaft, passages in said sleeve member opening through the outer periphery thereof at points spaced angularly from each other, said last mentioned passages communicating successively With said rst mentioned passages and each communicating continuously With a different one of said separate passages throughout rotation of said sleeve member, an exhaust passage extending axially through said crankshaft, and a radially extending passage opening into said exhaust passage and communicating successively with said first mentionedpassages on rotation of said sleeve member.

6. In a fluid actuated motor, the combination of a motor casing, a plurality of cylinders sup ported by said casing, a crankshaft extending into said casing, pistons reciprocable in said cylinders and connected to said crankshaft for driving the latter, passages extending through said casing and opening through the inner Wall of the latter at points lying in a common plane perpendicular to the axis of said crankshaft, said passages communicating with the outer ends of said cylinders, separate passages extending through said casing at points spaced along said crankshaft on one side of said common plane, a sleeve member rotatable with said crankshaft, passages in said sleeve member opening through the outer periphery thereof at points spaced angularly from each other, said last mentioned passages communicating successively with said rst mentioned passages and communicating continuously with different ones of said separate passages throughout rotation of said sleeve member, and means for connecting said separate passages selectively to iluid supply and exhaust.

JOHN C. CURTIS.

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