US3848374A

US3848374A - Sanding drum structure in a drum sander

Info

Publication number: US3848374A
Application number: US00319728A
Authority: US
Inventors: K Hasegawa
Original assignee: Meinan Machinery Works Inc
Current assignee: Meinan Machinery Works Inc
Priority date: 1971-12-28
Filing date: 1972-12-29
Publication date: 1974-11-19
Anticipated expiration: 1991-11-19
Also published as: JPS4870989A

Abstract

A drum for use with the drum type sanding machine or drum sander which features a quick and ready replacement of a sanding surface member to and from the outer circumference of the drum. This drum is specifically equipped with a tubular air jacket which is adapted to entirely surround the drum outer circumference after onto which a suitable endless and seamless sanding surface member or sanding belt is placed so that a replacement of worn sanding belt with a new one may be performed simply and quickly by discharging compressed air filled up in the tubular air jacket disposed around the drum thereby to reduce the outer diameter of the drum and provide a sufficient gap between the drum and the sanding belt and by recharging compressed air into the air jacket thereby to fix the sanding belt rigidly in proper position for sanding operations.

Description

Hasegawa 1 51 Nov. 19, 1974 1 SANDING DRUM STRUCTURE IN A DRUM SANDER [75] Inventor:

[73] Assignee: Meinan Machinery Works, Inc.,

Aichi-Pref., Japan 22 Filed: Dec. 29, 1972 21 Appl. No.: 319,728

Katsuji Hasegawa, Nagoya, Japan [30] Foreign Application Priority Data Dec. 28, 1971 Japan 46-471288 52 US. 01. 51/373 51 1m. (:1 B24d 9/02 [58] Field of Search 51/373; 242/72 B; 294/63, 294/86.24, 93

[56] References Cited UNITED STATES PATENTS 683,123 9/1901 Knill 51/373 1,487,256 3/1924 Mall 51/373 2,113,836 4/1938 Hamilton 51/373 2,116,272 5/1938 Mall 51/373 2,225,073 12/1940 Miller 51/373 2,448,884 9/1948 Hamilton 51/373 4/1950 Mall 7/1957 51/373 Miller 51/373 Primary Examiner-Othell M. Simpson Attorney, Agent, or FirmWoodhams, Blanchard and Flynn [5 7] ABSTRACT A drum for use with the drum type sanding machine or drum sander which features a quick and ready replacement of a sanding surface member to and from the outer circumference of the drum. This drum is specifically equipped with a tubular air jacket which is adapted to entirely surround the drum outer circumference after onto which a suitable endless and seamless sanding surface member or sanding belt is placed so that a replacement of worn sanding belt with a new one may be performed simply and quickly by discharging'compressed air filled up in the tubular air jacket disposed around the drum thereby to reduce the outer diameter of the drum and provide a sufficient gap between the drum and the sanding belt and by recharging compressed air into the air jacket thereby to fix the sanding belt rigidly in proper position for sanding operations.

9 Claims, 2 Drawing Figures I SANDING DRUM STRUCTURE IN A DRUM SANDER BACKGROUND OF THE INVENTION The present invention relates to the field of polishing machines, and particularly to a new and useful device which is applicable to the drum type sanding apparatus or drum sander. More particularly, this invention is concerned with a drum of unique design and construction adaptable to polishing or sanding operations, which is designed for use with the drum sander enabling a sanding surface member or sanding belt to be easily fixed and detached to and from the drum.

This invention is intended for easy replacement of the sanding surface material by means of a drum having a uniquely designed diameter reduction mechanism which permits a ready and quick replacement of the sanding surface material to and from the outer circumference of the drum for a drum sander, thereby to afford efficient sanding operations.

In the conventional drum sander, it requires considerably awkward jobs such as cutting a strip of the sanding surface material from a roll of same in an exact length corresponding to the outer circumference of the sanding drum and fixing the cut strip properly around the outer circumference of the drum without any gap between the cut ends of the strip, thereby to attain a complete sanding surface installation on the outer circumference of the drum. Moreover, such toilsome jobs are repeated at each time of replacement of the sanding surface member.

Furthermore, since there exists a seam between the abovementioned cut ends of the sanding surface member on the outer circumference of the drum, it is inevitable that such seam will give undesirable marks on the finished surface of the product, and consequently, it is practicably impossible to obtain a clean scar-free finish on the surface of the product.

On the other hand, in case of the conventional wide belt sander using an endless belt, it is possible to eliminate the abovementioned defects and problems encountered in the drum sander due to the use of the sheet type sanding material, thereby to result in satisfactory sanding operations.

Generally speaking, however, this type of machine has the following drawbacks, i.e., requirement for a plurality of rolls as well as specific extra means for giving the belt proper tension or effecting automatic running adjustments, despite its satisfactory sanding operations. Therefore, there will be brought about such problems from an economical point of view, as an increase of production cost, intricate and toilsome maintenance services, etc. due to the complicated construction thereof as compared with the drum sander which is simply constructed and handled.

SUMMARY OF THE INVENTION In consideration of the above stated defects and problems which are inherent to the conventional design and construction of a sanding apparatus, either of the drum sander or the wide belt sander, it would be advantageous to provide a drum for use with the drum type sanding apparatus of novel and unique design concept, which enables the outer diameter thereof to be reduced by means of deflatable air jacket incorporated under the circumference of the drum complete, for readily and quickly replacing an endless sanding surface member or sanding belt thereby to eliminate the abovementioned defects and problems inherent to the sanding apparatus of the conventional design and construction. This invention is directed essentially to meet such requirements which have long been left neglected.

It is therefore a primary object of the present invention to provide a sanding drum for use with a drum sander incorporating a unique mechanism under the circumference thereof which enables the outer diameter of the complete drum to be varied by means of an air jacket to be inflated by compressed air therewithin, which does not require wearisome jobs of cutting and adjusting the sanding strip but does perfonn ready and quick replacement of the sanding surface member without any specific difficulty. Another object of this invention is to provide a drum of the unique construction'using an endless sanding surface member or sanding belt, which performs fixation of the sanding belt in an outstandingly precise order on the outer circumference of the complete drum. v

A further object of this invention is to provide a sanding drum for the drum-sander affording the use of an endless and seamless sanding belt, which eliminates such apprehensions as of rendering undesirable marks of a joint seam of the sanding member on 'the finished surface of the product.

According to the present invention, briefly summarized by way of'a preferred embodiment, there is provided a drum for use with the drum type sanding apparatus which comprises a tubular air jacket disposed on the outer circumference of the basic construction thereof, which air jacket is adapted to be deflated by discharging compressed air therefrom and inflated by recharging compressed air thereto, and a layer of resilient body disposed to flexibly surround the outer circumference of the air jacket, which layer of resilient body being adapted to assure a positive adhesion of the cylindrical sanding surface member during sanding operations, thereby to afford the use of the seamless cylin drical sanding surface member in a detachable manner, whereby the sanding surface member may be replaced readily and quickly to precision so required.

BRIEF DESCRIPTION OF THE DRAWING The nature, principle, and details of the present invention, as well as further characteristics and advantages thereof, will become more apparent from the following detailed description with respect to a preferred embodiment of the invention when read in conjunction with the accompanying drawing, in which like parts are designated by like reference numerals, and in which:

FIG. 1 is a side elevational view, partly in axial section, showing a complete sanding drum according to this invention with compressed air discharged from its air jacket to a deflated circumferential state; and

FIG. 2 is a side elevational view, partly in axial section, showing the same complete sanding drum as shown in FIG. 1 with its air jacket filled up with compressed air for fixing a sanding surface member in operating position.

DETAILED DESCRIPTION Referring to FIGS. 1 and 2 showing a preferred embodiment of the drum for sanding operations according to the invention for use with a drum type sanding apparatus or drum sander, there .is provided a cylindrical drum A which comprises the following composite members, i.e., a basic roll of rigid construction 2, an air jacket 1 which is installed snugly around the outer circumference of the basic roll 2 and designed with an inflatable-and-deflatable construction by charging or discharging compressed air, respectively, and a resilient body 3 having an appropriate thickness such as sponge rubber or the like which is adapted to entirely coat the outer circumference of the air jacket 1.

In the abovementioned design and construction of the drum A, the rigid construction of the resilient body 3 onto the outer circumference of the air jacket 1 is to merely show one example thereof, and it may therefore be detachably installed thereon.

The fundamental construction of the drum according to this invention is fully described hereinbefore, and onto the ultimate outer circumference of the thus constructed cylindrical drum A there is provided an endless and seamless sanding surface member or sanding belt 4 to be installed properly in position while the air jacket 1 is deflated by discharging the compressed air therefrom, thus a complete sanding drum arrangement is accomplished.

In applying to the abovementioned sanding drum according to this invention, the sanding belt 4 should necessarily be of an endless and seamless cylindrical construction which completely eliminates the aforementioned defects accompanying the conventional strip type of sanding material.

As is apparent from FIG. 1, when compressed air is discharged from the air jacket 1, the outer diameter of the complete cylindrical drum A is made appropriately smaller than the inner diameter of the sanding belt 4, whereas, when the air jacket 1 is filled up with compressed air therewithin, as shown in FIG. 2, the outer circumferenceof the complete drum A is properly inflated to an extent that the outer diameter of the complete drum A is increased enough to meet the inner diameter of the sanding belt 4 so that an entirely compensated fixation of the sanding belt 4 on the outer circumference of the complete drum A is thus accomplished. Therefore, quite an easy and quick replacement work is made available by virtue of the abovementioned unique construction of the complete drum A as well as the use of the endless sanding belt 4.

As fully described hereinbefore, the advantageous features of the construction of the cylindrical sanding complete drum A will insure an easy and quick replacement of the endless sanding belt 4, that is, when the sanding belt 4 is required to be replaced, compressed air within the air jacket 1 on the drum is firstly discharged, thereby the air jacket is deflated to reduce the outer diameter of the complete drum A, and then a worn belt is replaced with a new one. This replacement work will be conducted quite easily because there is no resistance to check removal of a sanding belt due to a substantial difference existing between the outer diameter of-the complete drum A and the inner diameter of the sanding belt 4.

Likewise, this is quite true with an installation of the sanding belt 4 onto the outer circumference of the complete drum A. After installation of the sanding belt 4 in right position on the drum, the sanding belt 4 will be firmly and precisely fixed in a predetermined position on the complete drum A simply by charging compressed air into the air jacket 1 on the drum as the outer circumference of the resilient body 3 will progressively grow radially outwardly when the air jacket 1 inflates under inner pressure therewithin so as to exactly reach and fit to the inner diameter of the sanding belt 4.

Consequently, by virtue of the use of the sanding drum according to the present invention, a replacement work of the sanding belt in the cylindrical form to and from the complete cylindrical drum A will be performed remarkably readily an quickly, and further an installation of the sanding belt in a predetermined position on the drum will be accomplished much more precisely without any particular difficulty when compared with the use of the conventional sanding drum and surface member, whereby an efficient sanding operation is afforded.

Moreover, by virtue of the use of the endless and seamless sanding belt, such apprehensions of printing undesirable marks of the seam of the conventional sanding strip on the finished surface of the product, as stated hereinbefore, will entirely be eliminated, and consequently, there willv be provided quite a satisfactory finish free from scars on the product surface.

Furthermore, the drum sander using the sanding drum according to the invention does not require any such complicated construction as required in the conventional wide belt type installation using an endless belt, which requires, as also stated hereinbefore, complicated adjustments as well as intricate and toilsome maintenance services during sanding operations, consequently, resulting in remarkably economical advantages from both manufacturing and maintenance standpoints.

By virtue of the advantageous features as outlined above, the sanding drum according to this invention meets the requirements which have long been unfulfilled, whereby it realizes with a simple construction a solution to the defects and problems inherent to the conventional sanding apparatus, of either drum type or wide belt type, and whereby it encompasses the advantageous features of the two conventional type apparatus, i.e., eliminating the problem of undesirable marks to be printed on the finished surface of the product by the seam of the sanding surface member for use with the conventional drum type sanding apparatus, yet further enjoying advantageous features of the drum sander, such as the simple construction, low production cost, free from the toilsome works, etc., thus essentially promoting an efficiency and rationalization of the sanding operations. 1

The invention has been described in an illustrative manner and 'it should be understood that the terminologies which have been used herein are intended to be only in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings;

surized fluid is discharged therefrom said jacket folds in a radial direction;

a cylindrical sleeve body surrounding said jacket,

said body being made of resiliently stretchable material and having an internal diameter larger than the diameter of the peripheral surface of said base to define therebetween an annular zone in which said jacket is disposed, said body being expanded radially outwardly when said jacket is expanded;

a seamless cylindrical sanding member separate from and surrounding said body and adapted to be releasably frictionally engaged with the outer surface of said body when said jacket and said body are expanded, said sanding member being separable from said body when said jacket is folded.

2. A sanding drum structure according to claim 1, in which said bellows means comprises substantially flat, radially inner and radially outer cylindrical walls interconnected by foldable side walls, said inner and outer walls defining substantially cylindrical inner and outer surfaces with said inner surface being adapted to releasably frictionally grip the peripheral surface of said base when said jacket is expanded; said side walls being foldable toward each other when pressurized fluid is discharged therefrom.

3. A sanding drum structure according to claim 2, in which said body is attached to the outer wall of said bellows means.

4. A sanding drum structure according to claim 2, in which-said body is separate from said bellows means, said body being contacted by said outer wall of said bellows means and being expanded radially outwardly when said bellows means is expanded so that said body releasably frictionally grips and is supported by said bellows means.

5. A sanding drum structure according to claim 1 wherein means are provided to hermetically seal compressed air within said jacket so as to maintain a high pressure therewithin enough to rigidly support said body during sanding operations.

6. A sanding drum structure according to claim 1 wherein said body is made of sponge rubber.

7. A sanding drum structure according to claim 1 in which said body is free from connection to and support by said base except through said jacket.

8. A sanding drum structure according to claim 7, in which the axial ends of said body extend axially beyond the axial ends of said jacket and the axial ends of said sanding member are disposed directly radially outwardly of the axial ends of said jacket.

9. A sanding drum structure according to claim I, in which said jacket comprises a series of axially spaced, circumferentially extending jacket sections each having substantially flat inner and outer walls.

Claims

1. A sanding drum structure, comprising: a sanding drum base having a substantially cylindrical peripheral surface; a tubular inflatable jacket surrounding said peripheral surface, said jacket comprising radially foldable bellows means inflatable by pressurized fluid so that when pressurized fluid is supplied thereto said jacket expands radially to snugly engage said peripheral surface of said base and to define a substantially cylindrical outer surface, and when pressurized fluid is discharged therefrom said jacket folds in a radial direction; a cylindrical sleeve body surrounding said jacket, said body being made of resiliently stretchable material and having an internal diameter larger than the diameter of the peripheral surface of said base to define therebetween an annular zone in which said jacket is disposed, said body being expanded radially outwardly when said jacket is expanded; a seamless cylindrical sanding member separate from and surrounding said body and adapted to be releasably frictionally engaged with the outer surface of said body when said jacket and said body are expanded, said sanding member being separable from said body when said jacket is folded.

4. A sanding drum structure according to claim 2, in which said body is separate from said bellows means, said body being contacted by said outer wall of said bellows means and being expanded radially outwardly when said bellows means is expanded so that said body releasably frictionally grips and is supported by said bellows means.

9. A sanding drum structure according to claim 1, in which said jacket comprises a series of axially spaced, circumferentially extending jacket sections each having substantially flat inner and outer walls.