US2522695A

US2522695A - Machine tool guide

Info

Publication number: US2522695A
Application number: US709323A
Authority: US
Inventors: John M Walter
Original assignee: GA Gray Co
Current assignee: GA Gray Co
Priority date: 1946-11-12
Filing date: 1946-11-12
Publication date: 1950-09-19
Anticipated expiration: 1967-09-19

Description

Sept. 19, 1950 J, WALTER 2,522,695

MACHINE TOOL GUIDE Filed Nov. 12, 1946 IN VEN TOR. JbH/v M /1 4L r54 ATTORNEYS- Patented Sept. 19, 1950 2,522,695 MACHINE-TOOL GUIDE John M. Walter, Cincinnati, Ohio, assignor to The G. A. Gray Company, Cincinnati, corporation of Ohio Ohio, 21.

Application November 12, 1946, Serial No. 709,323

7 Claims. 1

My invention relates to machine tools in which a column or saddle of large size and weight is caused to move or be adjusted along rectangular ways, the column or saddle as the case may be, having channelled portions Which engage over the ways.

In apparatus of this type there are usually a series of parallel ways, say three as a normal number, and one of them is used as a closely controlled guide for the column or saddle. The column or saddle at this point is provided with tapered gibs so as to attain a close fit to the selected' one of the ways, and this selected way is called the narrow guide. The usual practice is to select as the narrow guide the one of the ways closest to the line of application of the instrumentality which moves the saddle or column with respect to the ways.

Despite careful arrangements on the moving saddle or column with gibs etc. to control the movement thereof, there is in large size installations such as floor type and planer type boring machines, and machines having ways on a vertical column on which a heavy saddle or head is caused to move, a tendency of the moving part to weave or wander during a slow progressive movement. Such wandering movement, which is a slight swinging from side to side may give rise to inaccurate work, or to jerky motion, and my invention is directed to avoiding it.

The way in which I accomplish this is to combine with a suitable gibbing of the moving element to the narrow guide, an adjustable spring loaded roller arrangement which urges the moving part normally to the narrow guide. In this connection I have found that such rollers will not operate satisfactorily with the usual cast iron of the body of the supporting part so that a bearing strip is provided on any cast iron wall on which the rollers bear. The point of preferred location of the spring loaded rollers on the moving part, I have found to be opposite to the gibs and special bearing faces in the saddle which operate on the narrow guide. If there are two such gibs and special bearing faces, I have found it desirable to use two of the roller arrangements. In the usual construction the spring loaded roller engages the wear strip insert, on the outside lateral face of the outer way or guide, on the side of the bed or support that is gibbed. By this device the adjustment of the gib can be arranged after the spring loading has been set into action.

I have illustrated my invention as applied to a column of a boring mill which is moved for purposes of adjustment of its position with reference to the work or a work'supporting bed. In:

the claims that follow will be set forth the novelty which is inherent in structures such as are 11- lustrated by this example.

In the drawings:

Figure 1 is a plan view showing the application of my invention.

Figure 2 is an end View or elevation.

Figure 3 is a section through the spring loaded In the drawings l illustrates a bed with three ways 2, 3, and 4, of which the way 3 may be taken as the narrow guide. The portion shown at 5 may be taken to be a baseplate on which is supported the column of a large boring mill. channels 6, 1, and 8 formed in the said base 5. which ride over the ways, the load being supported by the fiat bottoms of the channels on the top surface of the Ways. channel 1 are equipped as follows: At the left (in the particular showing), slide bearing plates 9 are inset into the side walls at the two ends of the channels. Another way of accomplishing this is to machine portions 9 very accurately on the channel side wall, and scrape out the metal between the two machined portions. On the other walls of the channel a tapered gib I0 is arranged at each end opposite the bearing faces 9, which gibs are adjustable, having their tapered face against the channel walls which are tapered to react with them. The usual or conventional gib arrangement is all that is required.

At the right hand overhang of the base on the bed will be located the usual hold down plate I I, which engages underneath the right hand way on the bed. As so far described the arrangement is one which has been employed frequently in the past.

At two points (in the illustrated showing) pockets l2 are formed in the underside of the base overhang, in which pockets are located slide blocks 13. The blocks are recessed for mounting a pin [4 which carries, preferably, a roller bearing l5 on the outer race of which is fixed an annular contact roller l6. Extending along the side of the overhang is a channel into which is forced a bearing plate of hardened steel as indicated at IT. The rollers contact with the bearing plate as the base moves over the bed.

In order to load the sliding blocks l3 and the rollers held therein, I provide heavy helical springs l8, seated in cavities in the outer faces of the blocks, and compressed by plates I9. The plates are held adjustably on the side wall of There are The side walls of the 3 the overhang by means of bolts 20, the position of which may be adjusted.

The result of this arrangement, as had already been noted, is that the horizontal zone of the moving base at the level of the ways and narrow guide is constrained toward one side, with the bearing faces 9 in contact with the side of the narrow guide, and naturally with the gib adjusted to give a smooth sliding engagement. The eifect of the springs is to prevent any wandering movement of the base as it moves along by maintaining the engagement under a spring bias. The fact that the spring loading or bias is seemingly slight as compared to the great. gravity load of the members in question does not appear to be a decisive factor in the effectiveness of the construction. When properly adjusted, a saddle or column so equipped will move without deviation with respect to the narrow guide in constructions of the type noted, an operation which is not obtained with the same gibbing' of the sliding member in the absence of the spring loading.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a machine tool, the combination of a support having outer and inner ways over which a member is moved, said member having channels in its base which ride on said ways, one of said channels having means to engage the sides as well as the top of one of .said ways, as a narrow guide, said means comprising interspaced surfaces one at each end of one side wall of said channel, and adjustable tapered gibs constituting a bearing between the other channel side wall and the other side of the narrow guide, and located in opposition to the position of said interspaced surfaces, and rollers mounted on the member, and bearing on the support, spring means for pressing the rollers against said support, said rollers being located on the side of the support which is the tapered gib side of the said channel on the narrow guide.

2. The combination of claim 1 in which the rollers engage the side wall of an outer one of the ways.

3. The combination of claim 1 in which the rollers are located one opposite each gib.

4. The combination of claim 1 in which the rollers are located one opposite each gib and engage the side wall'of an outer one of said ways.

5. The combination of claim 1 in which the rollers are located one opposite each gib and engage the side wall of an outer one of said ways, said side wall having inserted therein a hardened bearing strip located in the path of the rollers.

6, In a machine tool the combination of a support having inner and outer fiat surfaced ways thereon, a member moving on said support and having-channels to engage over the ways, one at REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATEN'ITS Number Name Date 874,848 Karns Dec. 24, 1907 1,381,188 Gury June 14, 1921 1,811,508 Klages June 23, 1931 2,167,609 Dolle July 25, 1939 2,195,841 Schlitters Apr. 2, 1940 2,378,212 Giern et a1. June 12, 1945 2,435,849 Schlitters Feb. 10, 1948