US1835573A

US1835573A - Sanding machine

Info

Publication number: US1835573A
Application number: US202021A
Authority: US
Inventors: Robert A Ponselle
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-06-28
Filing date: 1927-06-28
Publication date: 1931-12-08
Anticipated expiration: 1948-12-08

Description

C- 1931. R. A. PONSELLE SANDING MACHINE Filed June 28, 1927 2 Sheets-Sheet l INVENT 6M4. M2 161 g JZ m,M Z 7 ATTORNEYS Dec. 8, 1931. R. A. PONSELLE SANDING MACHINE Filed June 28, 1927 ATTORNEYS 2 Sheets-Sheet 2 Patented Dec. 8, 1931 PATENT OFFICE ROBERT A. PoNsELLE, on NEW YORK, N. Y.

SANDING MACHINE 1 Application filed June 28, 1927. Serial No. 202,021.

This invention relates to sc -called sanding machines used for wood working purposes and is concerned more particularly with an abrasive tool or element used in sue a machine to perform the actual work. This tool is mounted on the machine to be rotated .at a suitable rate of speed and has an abrasive surface which contacts with the article to be operated on.

The tools employedfin machines of the kind referred to ordinarily include a support which is 0 eratively connected to a driven shaft, and t e abrasive surface takes the form of a disc of abrasive sheet material removmovably secured to the support. As" these discs become worn and lose their abrasive qualities in service, more or less frequent replacement is required, dependin on the character of the material being woi' ked, and the operation being performed.

The object of the present invention is to provide a sanding machine which includes a readily removable abrasive tool, this tool being so arranged and constructed that replacement of the worn abrasive disc is easily and rapidly accomplished. The new tool further includes a reliable clampin means for holding the disc in position w ile the tool is in use and also a locking device for locking the clamping means a alnst releasing the disc during use. This lbcking device 1s brought into action and is eflective only when the tool is mounted in operative position in the machine, and accordingly, 1t 1n no way interferes with the release of the clamping means under those conditions that would prevail when such release is intentional and replacement of a disc is to be made. So long as the tool is in operative osition, however, the clamping means is loc ed and the disc is held firmly so that tearing or other injury to it is avoided. v

The new tool is of especial utility in a portable sanding machine to be used for treating wood floors andt-hat adaptation of on upper and lower ball bearin 17, 18, on a stud shaft 19 extending through 5 the invention will be described merelyfor purposes of illustration. In one such machine the tool or element is mounted on the end of a vertical driven shaft, and the face of the tool covered with the abrasive disc lies in contact with the floor, the entire weight of the machine pressing the cutting surface against the floor.

The construction of a sanding machine for treating floors is illustrated in the accompanying drawings, in which,

Fig. 1 is a view of a convenient form of the sanding machine in side elevation with certain parts shownin vertical section on the line 11 of Fig. 2,

Fig. 2 is a transverse sectional view on the line 2-2 of Fig. 3,

Fig. 3 is a view in side elevation showing the driving connections and the tool detached from the remainder of the machine,

Fig. 4 is a transverse section on the line 4-4 of Fig. 1, O

Fig. 5 is a vertical section on the line 55 of Fig. 4, Y

Fig. 6 is a sectional view of a detail, and

Fig. 7 is a face view of the abrasive disc.

' While the present tool is suitable for use with various types of machines to be used for different purposes, it is here illustrated in the form most suitable for use in a sanding machine for operating on floors. This machine includes a base or frame 10 on which is mounted an electric motor 11 having a driving shaft 12 which drives a chain 13 through suitable gearing and a vertical shaft mounted within a housing 14. The chain drives a sprocket wheel 15 mounted on the upper end of a tubular hub 16 which is in turn mounted assemblies a boss 20 in the frame and having a nut 21 at its upperv threaded end 22 b which the stud shaft is held in position. T e ball hear, ing assemblies are mounted in position with a driving fit and are held separated v,

; ill

than the diameter of the felt ring bular spacer 23. A cap plate 24, held in lace by screws on the lower end of the stud s aft, assists in holding the inner race of the lower assembly 18 in position, and a cap mounted on the lower end 0f the hub 16 by screws, serves to close the end of the hub and also supports the outer race of the lower bearing assembly. A ring plate 26 secured to the upper face of the sprocket wheel overlies the upper end of the tubular hub so as to prevent ghei) entrance of dirt into the interior of the Mounted on the lower face of the sprocket wheel around the hub is a ring 27 which is provided with a plurality of spaced depending lugs 28, each of which carries a plate 29 on its lower end, these plates lying in a plane parallel to the lower face of the sprocket Wheel. Each plate is held in position by screws 30 which extend through the lug and the sprocket wheel and-also serve to hold the ring 27 in place on the sprocket wheel. The

plates 29 project beyond the lugs in the direction in which the sprocket wheel is to be driven.

The tool includes a support 31 provided with a fiat disc 32 at one end and on its opposite face the support has a tubular extension 33 forming a recess 34. On the upper end of the extenslon is a ring 35, having tangential arms 36 corresponding in number to the number of lugs 28. Each of the arms has an under-cut portion, and the arrangement of the arms is such that the tubular extension of the sup ort may be passed over the end of the sha t and by a turning movement of the support the lates 29 on the lugs 28 may be engaged in the under-cut recesses in the arms. The support may thus be mounted on the lugs of the ring 27 carried by the sprocket wheel 15 and a driving connection between the s rocket wheel and the support is thus established. When the support is to be removed from the end of the shaft, the support is given a slight turning movement, freeing the arms from the plates 29, whereupon the support may be removed from the shaft endwise.

The sup rt has a central depression 37 having a s oping side wall, and a ring 38 of yielding material such as felt, is secured to the lower face of the plate 32. Secured in the support is a threaded stud 39, held in position in any convenient manner and proecting downwardly into the depression, as shown in Fi 1.

The abrasive material 40 is in the form of a circular disc of slightly greater diameter 38. The abrasive disc has a central hole 41 and a 1uralitv of slits 42 are cut radially in the isc, as illustrated in Fig. ,7. The circle drawn through the outer ends of the slits is of substantially the same diameter as the inner diameter of the ring of felt, and when, the

abrasive disc is placed on the face of the felt the tabs 43 defined by the slits are bent inwardly so as to lie against the sloping wall of the depression 37 These tabs are clamped in position against this wall by a clampmg device consisting of a ring 44'having a side wall of the same slope as the slope of the wall of the depression. A circular plate 45 has a channel 46 in its edge in which is received the inner edge of the ring 44, and plate 47 secured to the face of the plate 45 slightly overlies the portion of the ring 44 received in the channel 46. The ring 44 and the plate 45 are thus secured together a ainst detachment but are capable of relatlve movement. The plate 45 has a central hub 48 threaded on the end of the stud 39 and wing lugs 49 are formed on the lower face of the plate, these lugs providing means for turning the plate on the stud.

The upper face of the plate 45 is provided with a circular row of locking teeth 50 and mounted in a-boss 51 in the su port 31 is a pawl 52. This pawl has its lower end cut at an angle, as shown at 53, (Fig. 5) and it carries a pin 54 entering a notch in the lower end of the boss 51, the pin preventing the pawl from-turning. A leaf spring 55 is secured to the upper end of the pawl by means of a portion of the pawl which passes through a hole in the spring and is upset to form a rivet head. The spring 55 has a portion which extends inwardly toward the 11 per end of the stud 39 and this spring tends to hold the pawl retracted into the boss 51.

When the tool is to be put in operation, a disc of abrasive paper of the proper size is provided, the central hole is cut in it, and it is then slit radially, as shown in Fig. 7. The support, with the felt layer in po- -sition, is then turned up-side-down, the

abrasive disc is put in place, and the tabs are bent downwardly so as to lie against the sloping wall of the depression in the support. The late 45 with ring 44 secured to it, is now t readed on the stuu 39 and turned until the sloping face of the plate is brought into engagement with the tabs of the abrasive disc. The plate is turned until the face of the ring clamps these tabs tightly betweenthe face of the ring and the sloping wall of the depression in the support. The support is now placed on the end of the driving shaft of the machine and turned until the arms carried by the support are engaged by the lugs on the ring carried by the sprocket. If no locking means for the clamping device were provided, the rotation of the support accompanied by the jarring to which the machine is subjected in use, would cause the clamping device to become loose and the abrasive (1150 would sli and stand still so that it would do no usefu work and might become injured by the rotation of the support. v

With the present tool, however, the placmg of the support with the disc in place on the end of the shaft brings the spring 55 into contact with the end plate 25 on the hollow hub of the sprocket, and the spring is bent downwardly, forcing the pawl 52 into locking engagement with one of the teeth on the plate 45, The plate 45 is thus prevented from turning, and the tabs on the abrasive disc are securely clamped throughout the period of use of the machine. The spring is shaped so that if, when the support is mounted on the end of the hub of the sprocket wheel, the end cap projects downwardly to a greater extent than is necessary to force the pawl into locking engagement with the teeth, the spring is simply flexed to a greater extent without disturbing the engagement of the pawl and teeth.

As soon as the support is removed from the end of the shaft, the spring is free to return to its normal position, and it retracts the pawl from engagement with the teeth. The plate 45 may now be turned by the wing lugs, releasing the clamping ring from engagement with the tabs of the abrasive disc, and the disc may be removed and another one easily put in position. It will he observed that the ring 44 and the plate 45 are capable of'relative movement of rotation, but are otherwise secured together against detachment. This permits the clamping ring to be forced tightly into clamping engagement with the tabs of the abrasive disc, although the ring 44 does not turn. Conserpiently the tabs are not subjected to a tearing action. At the same time e clamping ring and plate are secured towiii be test.

new tool has been shown arranged e on a machine suitable for treating this machine having a carriage proa with wheeis 56 which may be swung nward into engagement with the floor erinit the machine to be moved over the 1 while the abrasive tool is clear of the tier. The machine is also provided with as usual handie 57, to which the motor E are secured, and the usual switch for control of the motor- 1s also mounted on he tool is adapted for other a tic-or machine, as will be sanding machine, the combination n shaft, a support removably mountthe end of the shaft, an abrasive disc sn, means for securing the abradisc in position on the support, and carried by the support for locking e "caring means in efi'ective position, the l means engaging the shaft when er so that there is no likelihood that the a locking device carried by the support andengaged by the shaft when the support is mounted thereon, the device being rendered effective thereby to lock the clamping disc in clamping position.

3. In a sanding machine, the combination of a driven shaft, a support removably mounted at theend of the shaft, an abrasive disc on the support, a clamping disc for holding the abrasive disc on the sup ort, this clamping disc being provided with ocking teeth, and a locking device carried by the support and engaged by the shaft when the support is mounted thereon, the device being forced thereby into locking engagement with the teeth on the clamping disc.

4. In a sanding machine, the combination of a driven shaft, 2. support removably mounted at the end of the shaft, an abrasive disc on the support, a clamping disc for holding the abrasive disc on the support, this clamping disc being provided with locking teeth, and a spring-pressed pawl carried blyl the support and forced by engagement wit the shaft when the support is placed there on into locking engagement with the teeth on the clamping disc.

5. In a sanding machine, the combination of a driven shaft, a. support removably mounted at the end of the shaft and having a recess into which the end of the shaft projects, an abrasive disc carried by the support, a clamping disc for holding the abrasive disc on the support, locking teeth on the clamping disc, and a spring-pressed pawl mounted on the support and forced by the spring into the said recess, this pawl being so arranged that it is forced out of the recess into engagement with the said locking teeth by engagement with the end of the shaft when the support is placed thereon.

6. In a sandin machine, the combination of a driven shaft, a support removably mounted at the end of the shaft and having a recess into which the end of the shaft pro jects, an abrasive disc carried by the support, a clamping disc arranged to clamp the central portion of the abrasive disc against the support, locking teeth on the clamping disc, a pawl on the support movable to engage the said locking teeth and thereby efiective to prevent the clamping disc from releasing the abrasive disc, and a spring on the support tending to hold the pawl out of engagement with the teeth, this spring being engaged by the shaft when the support is placed thereon, and flexed to force the pawl into engagement with the teeth.

7. In a sanding machine, the combination of a driven shaft, a support mounted on the shaft, an abrasive element,- means for holding the abrasive element on the support, and cooperating locking elements on the support and on the holding means, said elements being brought into locking engagement only when the support is mounted on the shaft.

In testimony whereof I aflix my signature.

ROBERT A. PONSELLE.