US2622939A - Carriage mounting - Google Patents

Description

Dec. 23, 1952 T. H. LJUNGGREN 2,622,939

CARRIAGE MOUNTING Filed June 29, 1946 2 SHEET$$HEET l Dec. 23, 1952 T. H. LJUNGGREN 2,622,939

CARRIAGE MOUNTING Filed June 29, 1946 2 SHEETS-SHEET 2 ifZk flifl? f Jim 15a 7 m; I I I g W flak 7 {4/ MM w 4/ I,

Patented Dec. 23, 1952 CARRIAGE MOUNTING Thor H. Ljunggren, Charlestown, N. H., assignmto Bryant Chucking Grinder Company, Springfield, Vt., a corporation of Vermont Application June 29, 1946, Serial No. 680,502

3 Claims. 1

This invention relates to the mounting of reciprocating carriages such as are employed to support and feed either work or one or more tools relative to each other.

One object of the invention is to provide an anti-friction mounting for the carriage with provisions for accurate adjustment of the carriage with respect to the line of travel.

A further object or" the invention is to separate the carriage supporting means from the means which guides and restricts the carriage motion.

Still another object is to apply the moving force to the carriage as near as possible coplanar or co-aXial with the resisting forces, thus to minimize displacement and distortion of the moving structure. This is particularly important in grinding machines where great accuracy is desired, feed motions being often in increments of less than ten thousandths of an inch or continuous at exceedingly low rates of speed.

A further object of the invention is to provide improved means for adjusting for wear while maintaining unaffected the accurate adjustment for traverse direction.

Another object of the invention is to provide an improved seal eiiective to prevent the entry of dust or other foreign matter to the antifriction surfaces.

Further objects and advantages will appear from a description of an embodiment of the invention shown in the accompanying drawings in which Figure 1 is a fragmentary top plan view of a carriage and its mounting in which the subject matter of this invention has been embodied, certain parts being shown by dotted lines.

Figure 2 is a front end elevation of the same.

Figure 3 is a detail sectional view on line 33 of Figure 1.

Figure 4 is a fragmentary view of a portion of the mounting partly in side elevation and partly broken away and in section.

Figure 5 is a detail sectional view to a larger scale on line 55 of Figure 1.

Referring to the drawings, at l is indicated a base member having parallel spaced ways 2 thereon. At 3 is a table mounted for traverse along said ways. As shown the table is provided with a pair of spaced depending ribs 4, each of which rests upon a series of rollers 5 journaled between pairs of spacer strips to which are positioned on opposite sides of each of the ways 2. These ways do not restrict the carriage motion to any horizontal direction. One of the parts comprising the support I and the carriage 5, and herein shown as the support, is provided between the ways 2 with a guide strip 6 havin one side wall 1 arranged widthwise perpendicular to the line of travel or" the carriage and as shown vertical, and the other side wall 8 flaring upwardly and outwardly so that the width of the guide strip 6 adjacent to its upper face is greater than at its lower face. This guide strip 6 rests upon and is secured to a surface Gil oi the base member so positioned that the axial center of the strip 6 substantially coincides with the plane, if not the line of the resultant of all the forces resisting feed motion of the carriage and provides means for accurately guiding the carriage along the ways. Such forces, for example, may include the pressure between a tool and a work piece, where one or the other is carried by the carriage, and friction between the carriage and the support on which it moves. For this purpose the carriage 3 is provided with guide rollers 9 and I0 spaced apart and bearing against the side 1 of the guide strip and a pair of spaced rollers H and [2 arranged to bear against the flaring side wall 8. The rollers H and [2 are somewhat conical in shape in order to properly engage the flaring wall 8.

The roller 9 is journaled on the fixed pivot 25 carried by the carriage 3. The other rollers it, II and I 2 are each journaled on a pivot it eccentrically disposed with relation to a circular head I! which is journaled in a circular recess I 8 in the under face of the carriage. This recess for the roller I!) has a reduced diameter upper portion [9 into which projects a post 20 extending upwardly from the head ii. The post 28 for the roller It] extends into a slot 2| in an axially movable adjusting rod 22, which as shown in Figure 1, is arranged substantially in the direction of travel of the carriage. The post 25 similar to the post 20 but for each of the rollers ii and I2 extends into a notch 23 in a longitudinal adjustable rod 24, the two rods 24 being substantially perpendicular to the direction of travel of the carriage.

The outer end of each of the rods 24 has attached thereto by a screw 30 threaded thereinto, an externally threaded plug 3| which is threaded into an internally threaded socket 32 in the carriage 3. The head 33 of the screw 30 is seated within a recess 34 in the outer end of the plug 31, this recess being of angular cross section to permit the insertion thereinto of a suitable tool of the same cross section (not shown) by which when the screw 30 is loosened slightly, the plug 3| may be turned to adjust it axially within the socket 32 thereby to adjust the corresponding rod 24 axially. After the adjustment has been effected, tightenin of the screw 30 will then lock the parts in position, the rod 24 being prevented from any substantial angular motion by the engagement therewith of the post 23. Axial adjustment of this rod, however, acts to turn the head H by engagement of this rod with the post 25, thus to adjust the corresponding roller toward or from the side wall of the guide member 6. The rod 22 may be similarly arranged for adjustment. The adjustment of this rod 22 which adjusts the position of the roller It, in conjunction with the non-adjustable roller 9, serves to accurately adjust the angular position of the carriage relative to the direction of motion of the carriage, the roller in bearing on the same face of the guide bar, and such adjustment once having been eifected may remain semi-permanent and may therefore be sealed off by any suitable means. The adjustments of the rods 24 will then serve to take up wear between the guide rollers and the guide bar and should be readily accessible for this purpose. Furthermore, the arrangement of the rollers is such as to make it feasible to release the rollers II and I2 by retraction of the rods 24 and thereby make it possible to dismount and remount the table 3 without disturbing its initial alinement. Such alinement is governed by rollers 9 and In which are fixed and sealed, respectively.

The carriage may be moved relative to the base by any suitable means, a conventional feed mechanism, including a lead screw 40 journaled in the bearing 400 on the carriage 3 and threaded into a nut 600 rigidly attached to the base memher I, on the surface 60, and a hand wheel 4| connected to the lead screw, being shown for this purpose. The screw 40 is in substantially axial alinement with the guide member 6. The flaring face 8 of the guide bar, and the correspondingly tapered rollers II and I2, act when these rollers are adjusted toward the guide bar to take up wear, to press the carriage downwardly, this component acting to increase the downward pressure of the carriage on its supporting rollers 5, thus counteracting a component force generally present which tends to lift the table. This lifting component in certain cases approximates or is larger than the weight of the moving system, comprising the table 3 and parts supported by it. Under static condition this may be of negligible importance but can, in dynamic status, be a seriously disturbing matter, as the moving system may be a supporting structure in a grinding machine, for example. The function of such structure is to control the relative positions between a tool (grinding wheel) and a work piece at closely controlled speed as well as extent of linear movement.

It is also desirable to prevent the entry of dirt and other foreign matter between the carriage and the base where it might interfere with the proper bearing of the carriage on the rollers and the rollers on the ways 2. Such a construction is shown in Figure 3 wherein one of these parts has secured thereto, as by screws 45, a slotted strip 46, the slot 41 of which is turned toward the other part, as shown, and the base I. Cooperating with this member 46 is a flexible plate 43 shown as secured to the base I as by a clamping strip 49, the free edge of this flexible plate 48 extending into the slot 41 and so curved as to bear at its free edge against one of the walls of this slot and adjacent to the free edge of the member 46 against the opposite wall. This provides a yielding seal between the carriage and the base which is effective to prevent the entry of foreign matter into contact with the supporting rolls.

From the foregoing description of an embodiment of this invention it should be evident to those skilled in the art that various changes and modifications might be made without departing from its spirit or scope.

I claim:

1. In combination with a base member having spaced parallel ways thereon, and a carriage member supported for motion along said ways, of a guide member carried by one of said first mentioned members between said ways and having spaced side walls extending in the direction of motion of said carriage, members spaced in two pairs lengthwise of said guide member and carried by the other of said first mentioned members, the members of each pair bearing on opposite sides of said guide member, one of said engaging members being non-adjustable, and the others of said engaging members being adjustable, and means for independently adjusting each of said adjustable engaging members to line up said carriage angularly to its direction of motion and to take up wear.

2. In combination with a base member having spaced parallel ways thereon, and a carriage member supported for motion along said ways, of a guide member carried by one of said first mentioned members between said ways and having spaced side Walls extending in the direction of motion of said carriage, rollers spaced in two pairs lengthwise of said guide member and carried by the other of said first mentioned members, the members of each pair bearing on opposite sides of said guide member, elements carried by one of said first mentioned members and on which said rollers are journaledQcertain of said elements comprising disks on which their respective rollers are eccentrically journaled, said disks being journaled in the other of said first mentioned members, a post eccentrically carried by each disk on the side opposite to its roller, a rod slidable axially in said other of said first mentioned members and having a portion engageable with said post, and means for adjusting said rods axially to thereby rock the corresponding disk and thereby adjust the positions of said disk-carried rollers.

3. In combination with a base having spaced ways thereon and a carriage supported for motion along said ways, of a guide member on said base having spaced walls, one of said walls being vertical and the other of said walls flaring upwardly and outwardly whereby the top face of said guide member is wider than the bottom face thereof, members spaced in pairs lengthwise of the carriage and engaging said side walls, one of said REFERENCES CITED The following references are of record in the file of this patent:

6 UNITED STATES PATENTS Number Name Date Birhanzl July 17, 1923 Isler Oct. 9, 1934 Einstein Nov. 27, 1934 Huffman July 25, 1939 Arms Feb. 4, 1941 Beckel Jan. 26, 1943 Rumpf June 29, 1943 Stabinski Sept. 21, 1943 Giern et a1 June 12, 1945

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