US2843981A

US2843981A - Abrasive drum

Info

Publication number: US2843981A
Application number: US648876A
Authority: US
Inventors: Block Aleck
Original assignee: Merit Products Inc
Current assignee: Merit Products Inc
Priority date: 1957-03-27
Filing date: 1957-03-27
Publication date: 1958-07-22
Anticipated expiration: 1975-07-22

Description

July 22, 1958 I A. BLOCK ABRASIVE DRUM Filed March 27, 1957 2 Sheets-Sheet 1 ?munuu n INVENTOR. flLECZ BLOCK Unitd rates Patent ABRASIVE DRUM Aleck Block, Los Angeles, Calif, assignor to Merit Products, Inc., Culver City, Calif., a corporation of California Application March 27, 1957, Serial No. 648,876

10 Claims. (Cl. 51193.7)

This invention relates to abrasive drums, and included in the objects of this invention are:

First, to provide an abrasive drum which is particularly designed to utilize wide sheets of abrasive, each having a margin extending radially and backed by a supporting brush, so that the tips of the sheets may engage a relatively wide workpiece as the drum is rotated.

Second, to provide an abrasive drum for wide sheets of abrasive wherein each abrasive sheet is wrapped on a corresponding spindle rotatably supported at each axial end of the drum, and wherein the several spindles are gear connected so as to rotate in unison to advance the abrasive sheets as their extremities become worn.

Third, to provide an abrasive drum of this type wherein the abrasive sheet supporting spindles are tubular and are longitudinally slit, and an end of the drum is provided with slots adapted to register therewith, when the spindles are turned to predetermined positions, and wherein the abrasive sheets are provided with retainer strips arranged to slip axially into the spindles; whereupon the spindles may be rotated in unison to wrap the abrasive sheets thereon, thereby providing a simple yet eflective means for quickly assembling the abrasive sheets on the drum or for quickly replacing worn sheets.

With the above and other objects in view, as may appear hereinafter, reference is directed to the accompanying drawings in which:

Figure 1 is a longitudinal sectional view of the abrasive drum taken substantially through 1--1 of Fig. 2;

Fig. 2 is an end view of the abrasive drum with portions broken away;

Fig. 3 is a fragmentary view of the opposite end of the abrasive drum with portions broken away.

The abrasive drum includes a shaft 1 on which iscentered a pair of end plates 2 and 3. Each end plate may be provided with an axially directed rib 4 concentric with the shaft 1. Supported on and extending between the ribs 4 is a ring of abrasive sheet storage tubes 5. Each storage tube may be square in cross section. The storage tubes are preferably welded, brazed, or otherwise secured to each other and to the end plates, or may be secured by other fastening means. The end plates 2 and 3 cover the ends of the storage tubes 5.

Mounted within each storage tube isa tubular spindle 6 journaled at its extremities in the end plates 2 and 3. The tubular spindles are equally spaced from each other and from the axis of the shaft 1. One end of each spindle is provided with a flange 7 which abuts the end plate 2. Each tubular spindle 6 is provided with a longitudinal slit. 8 extending the length of the storage tube and extending through the corresponding flange 7.

The outer side of each storage tube 5, preferably adjacent one radial wall, is provided with a longitudinal slit 9 extending the length of the storage tube. The end plate 2 is provided with a series of slots 10, each of which intersects a bearing opening of the end plate journaling a corresponding spindle 6, and extends to theperiphery of the: end plate along a line extending radiall from the Patented July 22, 1958 axis of the corresponding tubular spindle passing through the slit 9 of the corresponding storage tube 5. The spindles 6 may be turned so that their slits 8 register with the slits 9 of the storage tubes 5 and the slots 10 in the end plate 2 so that abrasive sheets may be inserted or removed, as will be brought out hereinafter.

The flanged end of each tubular spindle 6 may be normally closed by a cap screw 11.

The ends of the tubular spindles 6, opposite from the flanges 7, protrude through the end plate 3. Mounted on these protruding ends are spindle or planetary gears 12 disposed equidistant from the axis of the shaft 1.

Rotatably mounted on the shaft 1, adjacent the end plate 3, is a central or sun gear 13 which engages all of the planetary gears 12. A collar 14 retains the sun gear 13 on the shaft 1. The sun gear 13 may be provided with spanner ring sockets 15 so that it may be manually turned to turn the planetary gears 12 and their tubular spindles 6 simultaneously. Or, if desired, suitable turning means may be provided on any one or all of the planetary gears 12 to effect movement in unison of these gears.

Mounted between a pair of the planetary gears is a locking lever 16 having a locking pin or screw 17 so that the locking lever 16 may be moved into or out of engagement with the adjacent planetary gear 12 so as to lock all of the gears in various selected positions.

Each of the storage tubes 5 receives an abrasive sheet 18, the Width of which is equal to the length of the storage tube. Each abrasive sheet 18 is provided with retainer strips 19 suitably secured along one margin. The retainer strips 19 are of such dimension that they fit slidably within the tubular spindles 6.

The abrasive sheets 18 may be assembled on the drum structure by aligning the slits 8 of the tubular spindles 6 with the slits 9 of the storage tubes 5 and slots 10 of the end plate 2; then slipping the retainer strips 19 axially into their respective spindles while the abrasive sheets 18 are slipped axially through the slots 1d and slits 9. The tubular spindles 6 may then be rotated simultaneously to wrap the abrasive sheets 18 about the spindles until the storage tubes 5 are substantially filled. A free margin of each abrasive sheet 18 is permitted to remain extended substantially radially from the slit 9 of the corresponding storage tube 5.

Welded, brazed, or otherwise secured adjacent one margin of each slit 8 is a split tube 20. A backing brush 21 is provided for each split tube. Each backing brush includes a base member 22 which fits axially in the cor-.

responding split tube 20. A series of bristles 23 extend radially therefrom and thus form a support for the free end of the corresponding abrasive sheet 18.

Operation of the abrasive drum is as follows:

The shaft 1 is mounted for rotation between suitable bearings, not shown. The direction of rotation is such that the abrasive sheets are disposed at the leading sides of the backing brushes 21. The free extremities of the abrasive sheets are adjusted so that they extend approximately to the radial extremities of the backing brushes. This is accomplished by rotatably adjusting the planetary gears 12 and drawing outwardly on the free ends of the various abrasive sheets 18. It should be noted that the centrifugal force exerted-during operation will also eifect optimum extension of the free ends of the abrasive sheets 18.

On rotation of the abrasive drum the tip ends of the abrasive sheets 18 eventually wear. The planetary gears 12 are therefore adjusted from time to time to extend the abrasive sheets. In doing so, the locking lever 16 is released, the planetary gears 12 advanced one or more teeth, and the locking: lever 16 returnedto its locking position,

When it is desired to remove the remnants of used abrasive sheets 18, the cap screws 11 are removed, the longitudinal slits 3 are turned to a position of registry with the the slits 9 and slots 10, and the abrasive sheets are then slid axially from the spindles 6 and storage tubes 5. New abrasive sheets may then be installed.

The abrasive sheets 18 are formed of cloth or paper, coated with abrasive; or may be, in some cases, merely cloth which in the course of use is coated with abrasive material, such as rouge, by applying the abrasive material to the exposed ends of the sheets 18 as the drum is rotated.

It will be observed that the abrasive drum may be constructed so as to have any reasonable axial length so that relatively wide surfaces may be sanded or abraded by the abrasive drum. That is, the axial length of the drum may be several feet if desired, so that wide material may be handled.

While a particular embodiment of this invention has been shown and described, it is not intended to limit the same to the exact details of the construction set forth, and it embraces such changes, modifications, and equivalents of the parts and their formation and arrangement as come within the purview of the appended claims.

What is claimed is:

1. An abrasive drum, comprising: a drum structure including end plates and a plurality of storage tubes extending axially between said end plates and spaced equally from a common center; a tubular spindle in each storage tube; each storage tube, its spindle, and at least one of said end plates having axial slits adapted to register; abrasive sheets, each having a retainer element along one margin adapted .to be slipped endwise into a spindle as the adjacent margin of said sheet is slipped endwise into the corresponding storage tube; and means for rotating said spindles to Wrap said abrasive sheets thereon.

2. An abrasive drum, comprising: a drum structure including end plates and a plurality of storage tubes extending axially between said end plates and spaced equally from a common center; a tubular spindle in each storage tube; each storage tube, its spindle, and at least one of said end plates having axial slits adapted to register; abrasive sheets, each having a retainer element along one margin adapted to he slipped endwise into a spindle as the adjacent margin of said sheet is slipped endwise into the corresponding storage tube; means for rotating said spindles in unison initially to wrap said abrasive sheets about said spindles and thereafter to feed said sheets from said spindles, thereby to extend the free ends of said sheets a selected distance radially of said storage tubes; and brushes extending radially from said storage tubes to back the extended ends of said sheets.

3. An abrasive drum, comprising: a drum structure including end plates and a plurality of storage tubes extending axially between said end plates and spaced equally from a common center; a tubular spindle in each storage tube; each storage tube, its spindle, and at least one of said end plates having axial slits adapted to register; abrasive sheets, each having a retainer element along one margin adapted to be slipped endwise into a spindle as the adjacent margin of said sheet is slipped endwise into the corresponding storage tube; a planetary gear for each spindle; and a sun gear on said shaft for engagement with all of said planetary gears, said planetary gears being rotatable in unison to cause said spindles to wrap said abrasive sheets in unison thereabout.

4. An abrasive drum, comprising: a drum structure including end plates and a plurality of storage tubes extending axially between said end plates and spaced equally from a common center; a tubular spindle in each storage tube; each storage tube, its spindle, and at least one of said end plates having axial slits adapted to register; abrasive sheets, each having a retainer element along one margin adapted to be slipped endwise into a spindle as the adjacent margin of said sheet is slipped endwise into the corresponding storage tube; a planetary gear for each 4 spindle; a sun gear common to said planetary gears to rotate said planetary gears and spindles in unison initially to wrap said abrasive sheets about said spindles, and thereafter to feed said sheets from said spindles and extend the free ends of said sheets radially; and brushes extending radially from said storage tubes to back the extended ends of said sheets.

5. An abrasive drum adapted to utilize abrasive sheets having retainer elements along one margin, comprising: a pair of end plates; a plurality of storage tubes extending between said end plates and spaced equally about a common center; a tubular spindle in each tube journaled at its extremities in said end plate; each storage tube and its spindle having longitudinal slits and at least one of said end plates having slots in registry with the slits in the corresponding storage tubes, and the slit in each spindle being adapted to be rotated into registry therewith whereby retainer elements may be inserted into said spindles with the adjacent portions of said abrasive sheets extending through said slits; and means rotating said spindles to wrap said abrasive sheets therearound.

6. An abrasive drum adapted to utilize abrasive sheets having retainer elements along one margin, comprising: a pair of end plates; a plurality of storage tubes extending between said end plates and spaced equally about a common center; a tubular spindle in each tube journaled at its extremities in said end plate; each storage tube and its spindle having longitudinal slits and at least one of said end plates having slots in registry with the slits in the corresponding storage tubes, and the slit in each spindle being adapted to be rotated into registry therewith whereby retainer elements may be inserted into said spindles with the adjacent portions of said abrasive sheets extending through said slits; means for rotating said spindles in unison initially to wrap said abrasive sheets about said spindles and thereafter to feed said sheets from said spindles, thereby to extend the free ends of said sheets a selected distance radially of said storage tubes; and brushes extending radially from said storage tubes to back the extended ends of said sheets.

7. An abrasive drum adapted to utilize abrasive sheets having retainer elements along one margin, comprising: a pair of end plates; a plurality of storage tubes extending between said end plates and spaced equally about a common center; a tubular spindle in each tube journaled at its extremities in said end plate; each storage tube and its spindle having longitudinal slits and at least one of said end plates having slots in registry with the slits in the corresponding storage tubes, and the slit in each spindle being adapted to be rotated into registry therewith whereby retainer elements may be inserted into said spindles with the adjacent portions of said abrasive sheets extending through said slits; a planetary gear for each spindle; a sun gear common to said planetary gears to rotate said planetary gears and spindles in unison initially to Wrap said abrasive sheets about said spindles, and thereafter to feed said sheets from said spindles and extend the free ends of said sheets radially; and brushes extending radially from said storage tubes to back the extended ends of said sheets.

8. An abrasive drum, comprising: a drum structure including end plates and a plurality of storage tubes extending axially between said end plates and spaced equally from a common center; a tubular spindle in each storage tube; a plurality of abrasive sheets; means for interlocking each abrasive sheet with its spindle including cooperating interlocking elements formed longitudinally in said spindle and along a margin of said abrasive sheet and interengageable on relative longitudinal movement of said abrasive sheet; and means for rotating said spindles to wrap said abrasive sheets on said spindles.

9. An abrasive drum adapted to utilize abrasive sheets having retainer elements along one margin, comprising: a shaft; a pair of end plates mounted for rotation on for rotating said spindles to wrap said abrasive sheets therearound; and means for locking said spindles against rotation to secure the free ends of said abrasive sheets in predetermined extended relation with said spindles.

10. An abrasive drum, comprising: a shaft; a pair of end plates mounted for rotation on said shaft and having rings of aligned journal bores spaced from said shaft; a plurality of spindles journaled by their ends in aligned pairs of said bores; a plurality of abrasive sheets; cooperative means on said abrasive sheets and spindles for attaching each sheet by a margin to a corresponding spindle; a planetary gear for each spindle; a sun gear mounted on said shaft engaging all of said planetary gears to rotate said spindles in unison to Wrap said abrasive sheets simultaneously thereon; and locking means engageable with at least one of said gears to secure said gears against rotation thereby to secure said abrasive sheets in predetermined extended relation with said spindles.

References Cited in the file of this patent UNITED STATES PATENTS 564,587 Black July 28, 1896 2,046,122 Hunt June 30, 1936 2,198,047 Wick Apr. 23, 1940 2,522,920 Baltes Sept. 19, 1950 2,624,217 Clark June 6, 1953