US3543448A

US3543448A - Belt-platen abrading machine

Info

Publication number: US3543448A
Application number: US768022A
Authority: US
Inventors: Robert L Schaller
Original assignee: Sundstrand Engelberg Inc
Current assignee: Sundstrand Engelberg Inc
Priority date: 1968-10-16
Filing date: 1968-10-16
Publication date: 1970-12-01
Anticipated expiration: 1987-12-01

Description

Dec. 1, 1970 R. 1.. SCHALLER 3,543,443

BELTPLATEN ABRADING MACHINE Filed on. 16, 1968 4 SheetsSheet 1 INVENTOR. ROBERT L. SCHALLER.

BY W,

Dec. 1, 1970 R. L. SCHALLER 3543,44

BELT-PLATEN ABRADING MACHINE Filed Oct. 16, 1968 4 Sheets-Sheet 2 INVENTOR. ROBERT L. SCHALLER.

Dec. 1, 1970 R. L. SCHALLER BELT-PLATEN ABRADING MACHINE 4 Sheets-Sheet 4 Filed Oct. 16, 1968 llllallllllllllllllr INVlz'N'IOR. L. SCHALLER.

ROBERT 3,543,448 BELT-PLATEN ABRADIN G MACHINE Robert L. Schaller, Camillus, N.Y., assignor to Sundstrand Engelberg, Inc., a corporation of Delaware Filed Oct. 16, 1968, Ser. No. 768,022 Int. Cl. 1524b 21/12 US. Cl. 51-148 8 Claims ABSTRACT OF THE DISCLOSURE An abrading machine employing an endless abrading belt and having a platen for backing up a run of the belt. The platen and the belt tensioning mechanism are mounted in the machine framework in such manner that stresses developed by the tensioning mechanism are not transmitted to the platen. There is also included means operable to extend a small area of the abrading belt forwardly from the face of the platen for rapid rough grinding operation.

BACKGROUND OF THE INVENTION In the conventional structural arrangement of belt abrading machines having a backup platen, both the platen and the mechanism for supporting the idler roll and tensioning the belt are mounted on a common member constituting part of the machine framework. Especially, in large belt grinders employed for abrading large workpieces, the necessary tension applied to the belt is of considerable magnitude, creating stresses of substantial force in the machine framework, and these forces vary during the operation of the machine. With the platen attached to the same member, or a component of the same frame structure to which the tension mechanism is attached, these varying forces of substantial magnitude are transmitted to the platen, causing it to shift out of alignment, or from initial position. This shifting of the platen results in causing inaccuracies in the workpiece being abraded.

BRIEF SUMMARY OF THE INVENTION A vertically disposed heavy side plate is fixed to a base. An arbor housing is fixed in the lower portion of the side plate. The arbor for the lower drive pulley is journalled in this housing. An idler roll supporting and tensioning mechanism, in the form of a fluid operated cylinder, is fixed to the side plate above the drive pulley. Front and rear plates are fixed to the front and rear edges of the side plate and, in conjunction with the side plate and a second side plate fixed to the free edges of the front and rear plate, form a box structure positioned intermediate the lower drive pulley and the upper idler pulley. The front and side plates are arranged in spaced relation to the mounting of the tensioning cylinder. The platen is attached to the front plate.

With this arrangement, forces exerted by the tensioning cylinder are not transmitted directly to the platen. The platen is formed with a transversely extending slot intermediate its upper and lower edges and the ends of the slot terminate inwardly from the side edges of the platen. A bar is mounted in the slot for movement outwardly from the face of the platen to how the belt outwardly from the platen to present a relatively small transversely extending area of the belt to a workpiece. Upon movement of a rotating workpiece in engagement with this area of the belt, the reduced area of the belt effects a rapid removal of stock from the workpiece for rough grinding. After the rough grinding operation, the bar is retracted and the belt passes over the entire flat surface of the platen for precision grinding.

nitecl States Patent m 3,543,448 Patented Dec. 1, 1970 BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a side elevational view of an abrading machine embodying my invention. In the view, the central portion of the machine proper is shown in section, the section corresponding to line 1--1, FIG. 3.

FIG. 2 is a vertical sectional view taken on line 2-2, FIG. 1.

FIG. 3 is a transverse sectional view taken on line 33, FIG. 1.

FIG. 4 is an enlarged front elevational view of the platen, with a portion of the same broken away.

DETAILED DESCRIPTION A side plate 10 is fixedly secured, as by welding, to a plate 11 which, in turn, is fixedly secured to a base structure 12. The lower portion of the plate 10 is apertured to receive a cylindrical bearing housing 13, see FIG. 2, which is fixed to the plate as by Welding. A pulley arbor 14 is journalled in bearings 15 mounted in the housing 13, the arbor having a portion 17 extending in a direction laterally from the plate 10. A driving pulley 18 is fixedly secured to the extending portion 17 of the arbor.

Vertically disposed members 20 are fixedly secured to the inner surface of the plate 10. The members 20 are formed in their upper and lower portions with apertures 23 for the reception of cap screws 25 threaded into the end plates 27 of a cylinder 28. The cylinder 28 is accordingly vertically disposed, and the piston rod 30 has attached to its upper end a yoke 31, the leg portions of which carry bearings 33 in which is journalled a shaft 34 carrying an upper idler roll 35. The abrading belt 36 is trained over the

pulleys

18, 35.

Also fixed to the inner surface of the side plate 10 is a front plate 37 and a rear plate 38. These plates, like the cylinder 28, are arranged intermediate the

pulleys

18 and 35. The

plates

37, 38, are arranged in spaced relation to the members 20 and cylinder 28.

A second side plate 40 is fixed, as by welding, to the opposite ends of the front and

rear plates

37, 38, the

side plates

10, 40, and the front and

rear plates

37, 38, forming a box structure, see FIG. 3, overhanging the driving pulley 18. A platen support 41 is fixed to the front wall 37, as by screws 43, extending through the support and threading into the wall 37. The platen support 41 is also formed with threaded apertures to receive screws 45, the inner ends of which engage against the wall 37 and serve to adjust the spacing between the platen support and the wall 37 for the purpose of properly aligning the support.

A platen 47 is detachably affixed to the outer face side of the support 41. The platen may be afiixed to the support in a conventional manner wherein the platen is formed with V-grooves along its upper and lower edges for the reception of clamp members 48 moved into clamping engagement with the support by screws 50. With this arrangement, the platen is clamped snugly against the support member.

The platen 47 and the support member 41 are formed, intermediate their ends, with a transversely extending slot, the ends of which terminate in inwardly spaced relation to the side edges of the platen and support. A bar 57 is positioned in this slot for movement therein outwardly through the face of the platen. Stems 60 are attached to the bar 57 and extend inwardly through the support 41 and through the front wall 37. The stems 60' serve as piston rods, carrying pistons 61 mounted in cylinders 63 secured to the inner surface of the front wall 37, as by screws 62. The cylinders extend inwardly and have closures 65 at their inner ends. The closures 65 and the bases of the cylinders are provided with O-ring packings 67. The piston rods 60 extend through the end closures 65 and are provided with stop members 70 adjustable axially of the piston rods 60 by nuts 71.

When fluid under pressure is supplied to the inner ends of the cylinders 63 by line 73, the piston rods 60 and bar 57 are moved outwardly to the position shown in FIG. 1, this movement imparting a bowed condition to the abrasive belt 36. The limit of the outward movement of the bar 57 is determined by the setting of the stop members 7 on piston rods 60. The outer surface of the bar 57 is preferably provided with wear resisting material 74, such as tungsten carbide. Outward movement of bar 57 results in a small area of the belt 36 being presented to the workpiece, indicated at 75, the workpiece being mounted on the spindle of a rotary work fixture 76 driven by a motor 77, FIG. 1. Upon rotational engagement of the workpiece with the relatively small area of the belt pressed against the workpiece by bar 57, results in material being rapidly removed from the workpiece.

The rotary fixture 76 is mounted on a table 80 involving conventional slide structures by which the table is movable on the base structure 12 toward and from the abra sive belt, and also transversely thereof.

When the surface of the workpiece 75 has been rough ground, fluid is supplied to the inner ends of the cylinders 63 by line 83 to effect retraction of the bar 57 into the slots formed in the platen and the platen support, as shown in FIG. 3. Thereupon, the workpiece may be moved into engagement with the belt, which is then backed up by the flat and accurately adjusted platen for precision finishing of the workpiece.

An outboard bearing arm 85 is fixed to the outer surface of the side wall 40 and carries a bearing 86 in which the outer end of the arbor 14 is journalled. A plate 87 is fixed to the base plate 11 and extends upwardly therefrom in outwardly spaced relation to the side wall 10, and is connected thereto by a plurality of transversely extending stiffening members 88. The plate 87 and members '88, in conjunction with the side wall form a column structure imparting great rigidity to the plate 10. The yoke 31 is formed with a laterally extending arm 90, the outer end of which extends through a vertical slot 91 in plate 87 and into a vertical slot 92 in a plate 93 mounted for sliding movement in ways 94 attached to the outer surface of the plate 87, see FIGS. 1 and 2. A screw shaft 95 is operatively connected to the plate 93 for moving the same forwardly and rearwardly to swing the yoke 3-1 about the axis of the piston rod 30 to initially track the belt on the pulleys *18, 35.

What I claim is:

1. An abrading belt platen type abrading machine comprising a frame structure including a side plate, an arbor housingfixed in said plate, an arbor journalled in said housing with the axis of the arbor extending normal to said plate, said arbor having an end portion extending laterally from said plate, a drive pulley fixed to the extending end portion of said arbor, a cylinder mounted on said side plate, a piston and piston rod mounted in said cylinder, said rod extending from said cylinder in a direction away from said pulley, a yoke fixed to the extending end of said piston rod and an idler pulley journalled in said yoke, front and rear plates fixed to said side plate and extending laterally therefrom intermediate said pulleys at opposite sides of of said cylinder and spaced therefrom, a second side plate fixed to the free ends of said front and rear plates, a platen fixed to the outer surface of said front plate, an abrading belt trained over said pulleys with a run of the belt passing over said platen, and means operatively connected to said arbor to effect rotation of the same and said drive pulley.

2. An abrading machine as set forth in claim 1, wherein said side plate is fixedly secured to a base and extends upwardly therefrom.

3-. An abrading machine as set forth in claim 1, and including a second side plate fixed to'the free edges of said front and rear plates, and an outbroad bearing for the free end of said arbor attached to said second side plate.

4. An abrading machine as set forth in claim 1, and including means for detachably securing said platen to said front plate, and means for adjusting said platen relative to said front plate.

5. An abrading machine as set forth in claim 1, and including a platen mounting plate, means for detachably securing said mounting plate to said front plate, means for adjusting said mounting plate relative to said front plate, and means for detachably securing a platen to said front plate.

6. An abrading machine as set forth in claim 1, wherein said platen is formed in the surface confronting said abrading belt with a transversely extending slot, a bar positioned in said slot and means operable to move said bar outwardly from said platen into engagement with said abrading belt to effect a bowed configuration thereto.

7. An abrading machine as set forth in claim 1, wherein said platen is formed in the surface confronting said abrading belt with a transversely extending slot, the ends of said slot terminating inwardly of the side edges of said platen, a bar positioned in said slot, piston and cylinder structures mounted on the inner surface of said front side wall and being operatively connected to said bar to effect outward movement thereof into engagement with said abrading belt to effect a bowed configuration thereto.

8. An abrading machine as set forth in claim 1, and including an outer plate fixed to said base and extending upwardly therefrom in outwardly spaced relation to said first side plate, stiffening members extending transversely between said side plate and said outer plate and being fixed thereto and forming a column structure.

References Cited UNITED STATES PATENTS 3,134,206 5/1964 Olton et al. 51-142 3,136,096 6/1964 Hine 51142 3,451,174 6/ 1969 Schaller 51-148 OTHELL M. SIMPSON, Primary Examiner