US1548142A - Cylinder-boring mechanism - Google Patents

Description

Aug. 4, 1925. 1,548.142

- w. A. JENNINGS CYLINDER BORING MECHANISM Filed p i 14. 1922 llllllll/l! I z TZM M 7 w .1 a $16M; I J 2 z M a wilmiif QM,

Patented Aug: 4, 1925.

UNITED STATES WILLIAM A. JENNI Gs, or BAYTOWN, MISSOURI.

GYLINDER-BORING MECHANISM.

Application filed April 14, 1922. Serial No. 552,739.

To aZZ whom it may concern:

Be it known that I, WILLIAM A. JEN- NINGS, a citizen of the United States, and

resident of Raytown, Jackson County, Missouri, have invented a certain new and useful Improvement -in Cylinder-Boring Mechanism, of which the following is a complete specification.

This invention relates to apparatus for the boring or reboring of cylinders, and moreespecially of internal combustion engines, and has for one of its objects to produce an internal bearing for the cutter head so that such cutter head may always be held in alinement and against any wobbli-ng or springing which develops into a more or less eccentric motion and leads to an untrue boring of the cylinder.

Another object is to produce a device of this character which has an adjustable mandrel so that the device may be adapted to be used with cylinders of varying lengths.

A further object is to produce a cutter head provided with an internal bearing so constructed as to be readily adjustable to compensate for wear.

A still further object is to produce a device of the character described of simple, strong, durable, efiicient and inexpensive construction; and in orderthat it may be fully understood reference is to be had to the accompanying drawing, in which:

Figure 1 is a side elevation of a portion of a drill press and illustrates in section an engine block with the device of the invention inoperative relation thereto;

Fi re 2 is a'section on the line IIII of Figure 1;

Figure 3 is an enlarged section on the line TIL-III of Figure 1;

Figure 4 is an enlarged section on the line IV-IV of Figure 1;

Figure 5 'is a section taken on-the line V-V of Figure 3;

Figure 6 is a central vertical section thimgh a modified-form of the invention; an

Figure 7 is a section on the line VII-VII of Figure 6. i

In the said drawing, where like reference characters identify corresponding parts in all of the figures, 1 represents the standard of a drill press, 2 the base thereof and 3 the endof the customary driving shaft.

Mounted upon the base in any suitable manner and preferably of suflicient len th to accommodate an engine block, is a bri ge member 4, formed with an opening 5 of greater diameter than the largest cylinder to be bored and axially alined with the driving shaft 3, and also formed with a pair of inverted T-slots 6 for a purpose which will hereinafter appear.

Bolted as at 7 or otherwise secured to the underside of the bridge piece and closing the opening 5, is a retaining member 8 in which is driven, shrunk or otherwise rigidly secured, the lower extremity of a vertical shaft 9, which. will be positioned ,as near as possible with its'axis in vertical alinement with the axis of the driving shaft 3.

An engine block 10 is now disposed with one of its cylinders receiving the stub shaft 9, and such cylinder is axially alined withsaid stub shaft and theheads of a series of long bolts 11 may now be engaged in the T-grooves 6 of the bridge piece, and at their upper ends said bolts pass through perforations; in the ends of a pair of cross barsv 12 and by means of the customary nuts on the bolts, it will be evident that clamping pressure may be exerted on the cross bars to rigidly retain the engine block against side slip on the bridge piece, as will .be readily understood. The method of securing the block, however, is unimportant provided it is held rigidly in place. As illustrated, the en ine block is positioned with its cran case inverted, al-

desired position of longitudinal adjustment,

depending upon the type of press and the work to be done. The upper end of the though it will be apparent that it could member 13 is formed with a tapered extremity 17 for engagement within the customary socket formed in the lower end' of the operating shaft 3 of the drill press.

The lower end of the mandrel member 14,

'is threaded as at 18 for threaded engagement with the internally threaded upper end of a cutter head 19, it being understood in this connection that the internal diameter of the member it is greater than the diameter of the stub shaft 9.

Substantially centrally of its length the cutter head is split horizontally as at 20 for substantially one-half of its diameter, and the lower portion thus formed is provided with a air of ears 21 and with a central bore or aring 22, preferably,initially of slightly less diameter than that of the stub shaft 9. The split bearing thus formed, possesses more or less resiliency and the ears 21 will normally be spaced a slight distance apart. One of the cars 21 is formed with a pair of threaded openings and engaged in one of said openings and bearing at its end against the other ear 21 is a screw 24 formed with a socketed head. Upon rotation of the screw in the proper direction, it will be evident that upon the application of su fiicient force, the pair of cars 21 will be forced further apart and the diameter of the bearin 22 will be correspondingly increased. ngaging the second threaded opening in the ear, is the threaded extremity of a bolt 25 passing through a perforation in the other ear and formed at its end with a head for engagement by a wrench or the like. The internal bore 22 of the cutter head is adapted to find a bearin on the shaft 9 and as said bore gradua 1y increases in diameter under wear, the screw 24 will be retracted, and the ears 21 will move toward each other due to the resiliency of the split ring and the diameter of the bore will be correspondingly decreased. Whenthe entire contractive force of the split ring has been exhausted, the bolt 25 may be rotated to draw the ears together and further decrease the diameter of the bore 22, as will be readily apparent. It

- will be evident from the above that the life of the bearing 22 is thus doubled, as it is first expanded, allowed to contract, and then forcibl contracted. 7

Running horizontally of the cutter head and at the opposite side thereof from the cars 21 is a slot 26 forthe reception of a bit 27, the rear end of the bit bein slightliy recessed for abutment with a soc eted a justing screw 28 threaded in the rear end of the slot, it being evident that the adjustment of this screw may be used to vary the depth of the cut made by the bit. Between the rear end of the bit and the cutting end thereof, a second socketed screw 29 engages the cutter head and presses against the side of the bit in such a manner as to force said bit toward the axis of the cutter head, and a third socketed screw 30 threaded in an enlargement 31 of the cutter head engages the opposite side of the bit from the screw 29 and at a slight angle, and tends to counteract the pressure of the screws 28 and 29. It will be apparent from the above that the bit will be rigidly held in position against movement or springing action in any direc tion within its socket 26, and that it may be adjusted to vary the cut as found desirable. The stub shaft 9 isof such proportion as to inhibit springing movement, and as the cutter head hasa bearing on said stub shaft it will be evident that it will accurately maintain a fixed center and that the pressure on the stub shaft will always fall in the radius of the shaft passing through the point of contact of the bit with the cylinder wall. It has been found that a split ring is unnecessary for the operation of the cutter head, because the thrust from the point of the bit is radially inward and hence applied against the rigid shaft at all times. The split ring construction, forming a complete bearing, is desirable to overcome any possible tendency the bit might have to jump or dig into the cylinder walls, but it can be dispensed with as above stated.

It will be apparent from the above that the stub shaft is depended upon to center the bit, and that even if the axis of such-stub shaft is slightly out of line with the driving shaft 3, the stub shaft will counter-act any tendency the cutter head may have to wobble, and that, therefore, this wobbling or eccentric motion must occur in the mandrel and drive shaft, between the lowermost bearing of the latter and the cutter head.

It is desirable to point out in this connection that the bridge piece t is cut away as at 5, to permit the cutter head and bit to enter therein, thus boring the entire length of the cylinder without inversion of they engine blockor the elevation or lifting of the latter. When the engine block is positioned with its crankcase down, it will be evident that the opening 5 is unnecessary, as the cutter head will exit into the crankcase enlargement as will be readily understood.

In the device as illustrated in Figures 6 and 7 a modified form is shown in which: 9 illustrates the stub shaft, 14 the lower mandrel member, and 10 a cylinder which is desired to bore with tapering walls.

In order to accomplish this result, the stub shaft 9 must itself be tapered or, as illustrated, a tapering cone 32 may be slipped in position on said stub shaft, it being evident that it. is immaterial whether the cone revolves around the shaft or not, as will be readily understood. It will be apparent that in this instance it is impossible to employ a cutter head forming a complete ring, as described in connection with Figures 1 to 5, inclusive, as in such case, the cutter head could not slide down the ta ring cone. A cutter head 33 havin threa ed engagement with the mandrel an of substantially semicircular form is, therefore, employed (see 1rliiggre 7), it being evident that a cutter of this character will be free for down- 3 ward travel on the cone. It is desirable to point out in this connection that the mandrel for use in producing a tapering or irregular boring, must be flexible or provided with a universal joint 34, (see Figure I) in order to permit of downward travel of the cutter head and away from center, as otherwise the cutter head and cone will bind, involving too great an expenditure of power to overcome the friction which would thus be produced. A bit 34 is carried by the cutter head 33 in a similar manner to that above-described in connection withthe cutter head 19, and in such a position that the cutting point will lie in a radius of the shaft 9 passing substantially through the center of the circumference of the cutter head. It will be apparent that by varying the shape of the stub shaft or equipping it with an irregular sleeve 32 that the cutter could be caused to operate in conformity with the stub shaft or irregular sleeve, and produce a correspondingly irregular boring in the cylinder.

From theabove description it will be apparent that I have produced a device of the character described, which possesses all of the features of advantage set forth as desirable, and while I have described and claimed the preferred embodiment a of the same, Ireserve the right to make all changes properly falling within the spirit and scope of the appended claims. 7

I claim 1. A cylinder boring machine comprising a drive s aft capable of lateral movement, a rigidly secured vertical stub shaft alined with the drive shaft, and adapted to project into a cylinder to be bored, said stub shaft having a tapered portion, a cutter head carrying mandrel attached to the drive shaft and telescoping the stub shaft, said cutter head bearing onthe stub shaft on the cutter side of the head only whereby the tapered stub shaft serves as a. guide for the cutter head in its movement throu h the cylinder. 2. A cylinder boring mac e comprising a drive shaft having therein a universal joint, a rigidly secured vertical stub shaft alined with the drive shaft, and adapted to project into a cylinder to be bored, said stub shaft having a tapered portion, a cutter head carrying mandrel attached to the drive shaft and telescoping the stub shaft,-said cutter head bearing on the stub shaft on the cutter side of the head only whereby the tapered stub shaft serves 'as a guide for the cutter head in its movement through the cylinder. In witness whereof I hereunto aflix my signature. v WILLIAM A. JENNINGS.

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