US2004228A - Boring machine - Google Patents

Description

`lune l1, 1935.

A. STORM ET AL BORING MACHINE 5 Sheets-Sheet 1 F'ilevd NOV. '7, 1932 273391 June11, 1935. vA, STORM ETAL i 2,004,228

BORING MACHINE Filed Nov. '7, 1952 I 3 Sheets-Sheet 2 v 9b 91729-5 .E194

June11,1935. A, ST 5RM UAL 2,004,228

BORING MACHINE Filed Nov. '7, 1932 3 Sheets-Sheet 3 s; .55 56 gg 111111111.m1111112 Fly? d if' 7 7/ 72 0.58

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Patented June 11, 1935 UNITED STATES 2,004,228 BORING MACHINE Adolph Storm and Thor Thorsen,

Minn., assignors to Storm Minneapolis, Manufacturing Co.

Inc., Minneapolis, Minn., a corporation. of

Minnesota Application November 7, 1932, Serial No. 641,513

8 Claims.

Our present invention has for its object to provide al highly efficient portable boring machine for reestablishing, reboring and renishing bores in an engine cylinder block of accurate size and alignment.

To the above end, generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. l is a side elevation of the improved boring machine mounted on an engine cylinder block fragmentarily illustrated in vertical section taken centrally through the bores of said block;

Fig. 2 is a detail view partly in elevation and partly in section taken on the line 2 2 of Fig. 1;

Fig. 3 is a view principally in centralvertical section taken on the line 3 3 of Fig. 1;

Fig. 4 is a view partly in plan and partly in transverse section taken on the line 4 4 of Fig. 3;

Fig. 5 is a view principally in plan with the cover of the upper gear case removed and some parts sectioned on the line 5 5 of Fig. 3;

Fig. 6 is a view partly in elevation and partly in Vertical section taken on the line 6 6 of Fig. 5;

Fig. 7 is a View partly in plan and partly in transverse section taken on the line 7 1 of Fig. 3;

Figs. 8, 9 and l0 are detail views in section taken on the lines 8 8, 9 9 and I D I 0 of Fig. 3, respectively; and

Fig. l1 is `a perspective view of the cutter removed from the machine.

In the drawings there is fragmentarily illus? trated an engine cylinder block I2 on which the improved boring machine is supported in a perpendicular position. A clamp I3 holds the boring machine on the block` I2 in axial alignment with one of its cylinders I4.

The improved boring machine has an open bottom base I5 and a diametrically extended work passageway I6, the central portion of which is transversely expanded to afford a chamber I'I fora `combined 'cutter and centering head I8 when raised to a position above the bottom of the base I5 or the top of the block I2. The base I5 has an integral upstanding open ended substantially cylindrical housing I9 that is axially aligned with the `chamber II. Formed at substantially the vertical center of the housing I9 is an internal. Also formed in the housing gear chamber 20. I9 are two internal bearing seats 2|, one of which is above the gear chamber and the other of which is below the same.

A longitudinally split sleeve bearing 22 is mounted in each seat 2| and which seats and bearings have upwardly tapered engagement, the 5 one with the other, whereby when said bearings are moved upward in the seats 2l they will be contracted to take up wear. Each bearing 22 is adjusted and held where adjusted by a screw collar 23 which engages a shoulder on the housing 10 I 9 as a base of resistance. Screws 24 hold the bearings `22 from turning in their seats 2l. A long tubular bearing or guide bar 25 for a long tubular boring spindle is mounted in the bearings 22 for compound rotary and endwise feeding l5 movements.

`The head I8 is carried by the boring spindle 26 as an extension of its lower end and is detachably secured thereto `by a screw stud 21 on said head. Roller bearings 28 are interposed be- 20` tween the head I8and the guide bar 25 and other roller bearings 29 are interposed between the boring spindle 26 and a ring gear 3U, the hub of which is rigidly but detachably secured to the guide bar 25 at its upper end by screw threads, 25

as indicated at 3I. These roller bearings 28 and 29 hold the boring spindle 26 in axial'alignment with thefguide bar 25 for rotation therewith.

The guide bar 25 is rotated at a relatively slow speed with respect to the boring spindle 26, as 30- will presently appear, by an electric motor 32 mounted on va base 33 having a slide 34 held in an upwardly and outwardly inclined way 35 on the housing' I 9. A set-screw 36 and a slowmotion screw 3'I adjustably but rigidly secure the slide 34 35 to the way 35. Obviously', the screws 36 and 31 permit the motor to be raised or lowered to act as a belt tightener.

The driving connections for rotating the guide bar 25 from the motor 32 include a belt 38 which 40 runs over a grooved pulley 39 on the shaft of said motor and a grooved cone pulley 40 on a horizontal shaft 4I journaled in roller bearings 42 mounted in the housing I9. These driving connections further include a worm 43 on the shaft 45 4I in the gear chamber 20 which meshes `with a ring worm gear 44 secured to the lower end of a hub 45 on the guide bar 25. This hub145 is held for rotation with the guide bar 25 by a key 46 which extends into a long keyway 41 in said guide 50 bar and permits the required axial feeding movement of `the guide bar. The hub 45 is 'held against axial movement inthe housing I9 by the lower collar 23 and a shoulder on saidghousing.

Access may behad to` the interior of the gear chamber 39 through a side opening normally closed by a cover plate 48.

The boring spindle 26 is rotated by the rotary movement of the guide bar 25 but at a relatively fast speed by the following connections which include the gear 30. This gear 39, which is in a gear case 49, meshes with a gear 50 on a shaft 5I journaled in said case. The gear 59 meshes with an idle gear 52 which, in turn, meshes with a gear 53 on a shaft 54 having a large gear 55 which meshes with a gear 56 keyed to the boring spindle 26 above the guide bar 25. The gear-case 49 is formed with a cross-head 51 swivelled on the upper end portion of the guide bar 25 but held for common axial movement therewith. The gear 44 rotates the guide bar 25 'clockwise and the driving connections 30, 59 to 55, inclusive, drive the boring spindle 26 in the same direction.

'The guide bar 25 and the boring spindle 25 which .are held for common axial movement are fed endwise to move the head I8 downward by a rack 58 and cooperating pinion 59. This rack 58 is formed on a guide post 60 which extends parallel to the guide bar 25 and is rigidly secured at its lower end to the housing I9. The guide post 69 extends through a sleeve bearing 6I on the cross-head 51 and the pinion 59 is secured to a short shaft 62 journaled in said cross-head and a cover plate 63 for a gear case 64 formed with the cross-head 51. Y

The pinion 59 is driven from the shaft 5| by the following connections, to wit: Keyed to the shaft 5I is a worm 65 that meshes with a worm gear 66, in a gear case B1 formed with the cross-head 51, secured to a short shaft 68 journaled to the crosshead 51 and a cover plate 69 for the gear case 61.

A gear 10 mounted on the shaft 68 and. rigidly secured for rotation with the Worm gear 66 meshes with a gear 1I which constitutes the driving member of a cone clutch 12 and has a conical seat 13 for the cone or driven member 14 of said clutch. The gear 1I is rigidly secured to the inner end of a clutch spindle 15 rotatably mounted in a tubular clutch spindle 15 with freedom for a limited relative endwise movement to set or release the clutch 12, as will presently `appear. The clutch cone 14 is rigidly secured to the inner end of the tubular spindle 16 which is rotatably mounted in a bearing in the cross-head 51. Y On the outer end portion of the tubular clutch spindle 16, in the gear case 61, is a pinion 11 which meshes with a gear 18 keyed to the shaft 62 within the gear case 64. The clutch cone 14 and the pinion 11 hold the tubular clutch spindle 'I8 against endwise movement in its bearing. The spindles 15 and 16 project through an aperture in the cover plate 63 and materially out ward thereof and the gear 11 is provided with a long hub which also projects through said aperture and is secured to the tubular spindle 16 by a screw 19 for rotation therewith.

Mounted on the outer end portion of the hub of the gear 11 is a hand wheel 8l) secured for rotation therewith by the screws 19. A clutch knob 8l outward of the hand. wheel 88 is swivelled to the outer end of the clutch spindle 15 and has screw-threaded engagement with the tubular clutch spindle 16. Obviously by turning the clutch knob 8l on the clutch spindle 16 Ythe connecting screw threads will move the clutch spindle 15 endwse in the tubular spindle 16 and axially shift thev gear 'Il which contains Vthe clutch seat13 to set or release the clutch12. Obviously when the clutch 12 is set the rotation of the pinion 19 on the rack 58 will move the cross-head 51 downward on the guide post 69 and thereby feed the boring spindle 26 to its work. When the clutch 12 is released the hand wheel 89 may be manipulated to rotate the pinion 59 and thereby raise or lower fthe boring spindle 26.

A novel device in the form of a drag ring 82 is provided to prevent the guide bar 25 and parts carried thereby from moving downwardly in the housing I8 under the action of the weight thereof and thereby produce an unsteady feed to said bar. This drag ring 82, which encircles the guide bar 25 in the gear chamber 29, is transversely divided and the ends thereof spaced to receive the key 46 therebetween with sumcient clearance to permit the required contraction or expansion of said ring. Primarily, the internal diameter of the drag ring 82 is slightly smaller than the external diameter of the guide bar 25 so that the same is slightly expanded when applied thereto to frictionally connect the same. The external surface of the drag ring 82 is downwardly and inwardly tapered and mounted in a correspondingly formed seat 83 in the upper end portion of the hub 45 with freedom for slight axial movement in said seat. Obviously, the weight of the guide bar 25 and parts carried thereby on the drag ring 82 tends to move said ring downward. Independent downward movement of the guide bar 25 ahead of its feeding mechanism, due to lost motion in the feed gearing, is thus prevented, as the normal friction between the engaging surfaces of the drag ring 8?. and bar causes the ring to move downward with the bar in its tapered seat 83 and thereby further contract the same and increase he frictional engagement between the drag ring 82 and the guide bar 25.

During the lifting or retracting movement of the guide bar 25 the drag ring 82 will be moved thereby upward from its tapered seat 83 and permit the hinge to expand thus reducing the frictional contact between the drag ring 82 and guide bar 25 to facilitate said movement of the guide bar 25. Y

A cutting tool 84 is carried by a holder 85 removably mounted in a radial seat 88 in the head I8 near the underside thereof. This holder 85 may be adjusted radially in the seat 85 by a screw-acting member 81 to set the cutting tool 84 the proper distance from the axis of the head I8 to cut the walls of the respective cylinder tc the desired diameter. The adjusting member 81 has threaded engagement with the holder 85, projects rearward therefrom and impinges against the head I8 at the rear end of the seat 85 as a base of resistance.

A centering device is provided for centering the machine with respect to one of the cylinders I4 to be rebored or refinished previous to securing said machine to the block I2 by the clamp i3. This centering device includes three radial fmgers 88 mounted in seats'in the head I8 above the holder 85 and spaced equi-distances apart circumferentially about said head. These lingers 88 are simultaneously projected for engagement at their outer ends with the vwalls of the cylinder or retracted by a rotatable disc 89 mounted in the head I8 and having on its under side aspiralV screw thread 99 which meshes with racks 9| on the fingers 88.

The disc 89 may be manually rotated from the top of the machine by the following connections, to wit: A long operating rod 92 extending axially through the tubular boring bar 26 and head I8 has on its lower end a gear 93 that is connected by an idle gear 94 to an internal ring gear 85 rigidly secured t the disc 89. On the upper end of the rod 92 is an operating knob 96 having a hub 91 turnably mounted on the upper end por-` tion of the boring bar 25 and in a bearing 98 on the cover plate 99 for the gear case 49. Obviously by turning the operating knob 96 the centering iingers 88 may be projected or retracted, at will.

The clamp I3, as shown, is in the form of a horizontal bar having at one end` a fork, the prongs of which straddle the housing I9 and rest on the base at diametrically opposite points. In the under side of the body of the clamp I3 is a longitudinally extended T-slot in which the head of an anchor' bolt |00 is slidably mounted at the front end thereof. This anchor bolt |00 extends loosely through'a` transverse bar |0I which rests on the top of the block I2 over the cylinder I4 adjacent to the one to be bored and has threaded engagement with a nut |02 which connects the prongs of a U-shaped strap |03 having at its lower end a transverse channel anchor bar |04 that is intermediately pivoted thereto. This anchor bar |04 engages the blocks I2 at its under side at diametrically opposite sides of the cylinder I4 through which the anchor bolt |00 extends. A coiled spring |05 is compressed between the body of the clamp I3 and the bar |0I.

The body of the clamp I3, at its rear end, 'is held raised by a hand screw |00 to press its prongs onto the base I5 and thereby frictionally hold the machine on the top of the block I2. This hand screw |06 extends through a large hole in the body of the clamp I3, has screw-threaded engagement with a. nut |01 slidably mounted in the slot of said body. On the lower end of the hand screw |06 is a foot` |08 connected thereto by a universal joint and which foot rests on the block I2.

In the motor circuit is a cut-out switch |09 and a vertically adjustable collar II 0 on the guide bar 25 is provided for opening said switch at the limit of the downward feed of the guide bar 25.`

Operation The operation of the improved boring machine may be briefly described as follows: The driving connection from the motor 32 to the guide bar 25 rotates said bar at a relatively slow speed and the train of gears from the guide bar 25 to the boring spindle 26 rotates said spindle at a relatively fast speed. The object of the differential speed at which the guide bar 25 and the boring spindle 28 are rotated is to increase the accuracy oi' the machine by causing the cutting tool to move about a given center and not drift. In other words, the tool spindle bearing being constantly rotated as a whole about a common center with reference to the object being bored causes any inaccuracies in the boring construction, such as would permit the tool to drift or be oifcenter, to move about a circular path and thus evenly distribute the inaccuracies of the bearing around the entire circumference of the cylinder being bored. It is well known that if a drill or other boring tool is not held in a true position at the beginning of the bore, it will drift from a given center, with the result that the bore is not in true alignment. By rotating the guide bar 25 or bearing in which the boring spindle 26 is rotatably mounted and at a different speed, any inaccuracy which would tend to cause the cutting tool to drift is constantly shifted about a given center and hence the cut is made at said center and on a true axial line.

The guide bar 25 is moved axially by rack 58 and cio-operating pinion 59 and which pinion is driven "by connections actuated by the rotary movement of said bar to feed the same downwardly.`

i The object of the retarding device or drag ring 82 for the guide bar 25 or bearing for the boring spindle 26 is to overcome the unevenl feed of said bearing and hence that of the boring spindle 26 by the rack 58 and pinion 59. 'I'his uneven feed is caused by play between the teeth of the rack 58 and pinion 59. Obviously, as the teeth of the pinion 59 move out of engagement with the teeth of the rack 58, during the downwardly feeding movement of the guide bar 25, the weight of said bar and parts carried thereby would cause a slight intermittent gravity feed of the bar independent and ahead of the gear feed with a resultant unsteady feed imparted to the cutting tool. i

The drag ring 82, by its breaking frictional engagement with the guide bar 25 on downward movement of the bar, prevents any gravity feed 0f said bar so that the guide bar 25 is positively moved downward by the rack 58 and pinion 59 with a steady and even feed. As previously stated, the frictional contact between the drag ring 82 and the guide bar 25 is automatically increased during the downward movement of the guide barV 25 and automatically released by the upward movement of the guide bar 25.

While the driving connections illustrated in the drawings are designed to rotate the guide bar 25 and the boring spindle 26 in the same direction, it will, of course, be understood that connections may be designed to rotate said bar and spindle in reverse directions with the same result.

What we claim is:

1. In a machine of the class described, a base, a bearing rotatably mounted on the base, an upright boring spindle rotatably mounted in the bearing, means for rotating the bearing, feeding means for moving the bearing downwardly, a contractible and expansible drag ring through which the bearing extends axially, said ring being frictionally clamped onto the bearing, and a member held against axial movement with respect to the bearing and having a tapered seat for the drag ring, the taper of the seat being arranged to contract the drag ring during the feeding movement of the bearing.

2. In a machine of the class described, a base, a bearing mounted on the base for compound rotary and axial movement, an upright boring spindle rotatably mounted in the bearing, means for rotating the bearing, a feed device for moving the bearing axially, a sleeve keyed to the bearing for rotation therewith but held against relative axial movement, said sleeve having an internal annular seat that is downwardly and inwardly tapered, and a transversely divided drag ring in the seat and frictionally clamped onto the bearing and positively held for rotation therewith.

3. In a machine of the class described, a base, a tubular bearing carrying member mounted for rotatable and axial sliding movement through the base, a tubular boring spindle rotatably mounted in and coaxially supported by the 'bearings of said tubular bearing carrying member, a cutting tool carried solely by the boring spindle `for rotation therewith, means extending coaxially through the boring spindle and operatively connected to the cutting tool for adjusting the same radially from the upper end of said boring spindle, and means for constantly rotating the tubular bearing carrying member and boring spindle at relatively low and high speeds respectively during normal operation of the machine.

4. In a machine of the class described, a base a 'tubular bearing mounted for rotatable and axial sliding movement through the base, a boring spindle concentrically mounted in and supported by said bearing, a cutting tool fixed to the lower endv of said spindle for rotation therewith, means for rotating the bearing, and means operated by the rotary movement of the bearing for constantly rotating the boring spindle at a different speed from that of the bearing.

5` In a machine of the class described, a base,v

aftubular rbearing carrying member mounted for rotatable and axial sliding movement through the base, a boring spindle Vconcentrically mounted in and-supported by the vbearings of said tubular member, a cutting tool carried solely by the boring spindle for rotation therewith, means for rotating said tubular bearing carrying member, and a train of gears for rotating the boring spindle from the tubular member at relatively higher speed.

6. In a machine `oi the class described, a base, a tubular bearing carrying member mounted for rotatable and axial sliding movement through the base, a tubular boring spindle rotatably mounted in and supported by the bearing of said tubular bearing carrying member, a combined cutting and centering head secured to one end of said tubular boring spindle for rotation therewith, movable centering members mounted in said head, means rotatable with the boring spindle for adjusting said centering members from the other end of said tubular boring spindle, comprising an operatingrod extending axially through the boring spindle and boring means at its inner end operatively engaging the centering members, and hand operated means mounted on the outer end of said spindle and operatively connected to the outer end of said rod.

7. In a machine of the class described, a base, an upright boring bar mounted on the base for compound rotary and axial movements, a feed device for moving the bar axially, a rotatable member surrounding said bar and held against axial movement in the base, said member having a tapered annular seat at its upper end adjacent said bar, and a retarding device for holding the bar against downward movement independently and ahead of said feed device, said re, tarding device comprising a contractible and expansible friction ring surrounding the bar for rotation therewith and having a tapered face adapted to cooperate with the tapered seat in said rotatable member.

8. In a machine of the class described, a base, a guide post upstanding from said base, a tubular bearing carryingmember mounted for rotatable and axial sliding movement through the base parallel tofsaid guide post, a boring spindle concentrically mounted in and supported by the bearings of said tubular member, a cutting tool mounted on the lower end of said boring spindle for rotation therewith, a gear casing mounted on the upper end of said tubular member and slidably mounted on. said guide post, and gearing journaled in said casing and operatively connecting said tubular member and boring spindle for relatively different speeds of r0- tation.

ADOLPI-I STORM. THOR THORSEN.

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