US1707584A - Portable sanding machine - Google Patents

Description

April 2, 1929, v H. A. SWAN 1,707,584

PORTABLE SANDI NG' MACHINE File d Sept. 29, 1927 5 Sheets-Sheet 1 W flaw/7 if 6294/7, INVENTOR.

/ 0&5'666 ATTbRNEs s.

April 2, 1929. H. A. SWAN 1,707,584

PORTABLE SANDING MACHINE Filed Spc. 29, 1927 3 Sheets-Sheet 2 A TTORNEYS.

April 2, 1929.

/ V/ fnesaea H. A. SWAN 1,707,584

PORTABLE S ANDI NG MACHI NE Filed Sept. 29', 1927 s Sheets-Sheet 5 f/d/fa/a' 67040; INVENTOR.

A TTORNEYS.

Patented Apr. 2, 1 929.

UNITED STATES lEAROLD A. SWAN, OF CORONADO, CALIFORNIA.

PORTABLE SANDING MACHINE.

Application filed September 29, 1927. Serial No. 222,8.

This invention relates to improvements in sanding machines and has as its general object to provide a machine which will be highly efficient in operation and whichwill operate to abrade or sand the work to be dressed, in a highly eflicient manner and with the expenditure of much less time than is ordinarily required in performing this task.

Another object of; the invention is to provide a sanding machine of compact construction and operated through the medium of an electric motor, the machine being adapted to be conveniently manipulated and guided over the surface of the work to be dressed.

Another object of the invention is to provide a sanding machine which may be readily converted for use either by the employment of an endless belt as-the abrading medium, or by utilizing one of the rolls over which the belt is trained and by which it is driven, as the abrading means, so that the machine may be conveniently and readily converted from a belt sander to a cylinder sander, and vice versa, depending upon the character of the .2 work.

Another object of the invention isto provide novel means for transmitting power to the abrading element of the machine, whether it be a belt, or one of the rolls about which the belt is trained and from which the belt is driven.

Another object of the invention is to provide novel means for maintaining the lower or working stretch o'tthe abrading belt in fiat and even contact with the surface of the work to be dressed, Where the belt is employed as the abrading medium, and to provide for utilization of this means as a means for steadying and supportingthe machine for movement over the surface of the work, when the belt is removed and the drive or power roll of the machine is employed as the abrading medium.

While the accompanying drawings and the description which is to follow, constitutea disclosure of the preferred embodiment of the invention, it will be understood that various changes may be made within the scope of what is claimed. i

In the accompanying drawings: .Fig. 1 is a side elevation of the sanding machine embodying the invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a vertical longitudinal sectional view through the machine; Fig. 4 is a vertical transverse sectional view taken substantially on the line 4-4 of Figure 3 looking in the direction indicated by the arrows;

Fig. 5 is a similar view on the line 55 of Figure 3 looking in the direction indicated by the arrows;

Fig. 6 is a vertical transverse sectional view taken substantially on the line 6-6 of Figure 1 looking in the direction indicated by the arrows;

Fig. 7 is a front elevation of the machine, a part being shown in section.

The machine embodying the invention includes a body casting which includes a base 1, an electric motor casing 2 which is integral with the base 1 and located substantially at the center of the upper side thereof, and a gear case 3 which is likewise cast integral with the base and located at the rear. thereof and in rear of the motor casing 2. The electric motor of which the casing 2 constitutes a part, is of any approved type, and the conductor wires for the motor, indicated by the numeral 4, are led to the motor through the forward side of the casing 2, from any suitable source of current supply. Ears 5 are formed integrally with the oppositesidesof the base 1 at the rear end thereof, and a' spindle 6 is fitted through bosses 7 formed upon the inner sides of the ears and threaded at one end as'at 8 into one out the said bosses. A sleeve 9 is fitted onto the said spindle for rotation and supports the drive or ower roll of the machine which is indicated y the numcral 10. The under side of the base 1 isrecessed at the forward end of the base as indicated by the numeral 11, and a bearing member comprising a plate 12, is slidably adjustably disposed within the recess and is adapted to be adjusted in a forward and rearward direetion through the medium (if a screw 13 having right and left hand threads, one end of the screw being threaded into an opening 14 formed in an upstanding lug 15 formed inte ral with the upper side of the base 1, the ot er end of the screw being threaded through an opening 16 formed in an car 17 upstanding from the plate 12 at the forward slde of the said plate, the said ear 17 working in a slot 18 formed to extend in a front to rear direc tion longitudinally within the said base 1 at the upper side and front of the recess 11 therein. Ears 19 project downwardly from the opposite ends of the plate 12, and a spindle 20 corresponding to the spindle 6, is mounted at its ends in the said cars 13 and has rotatably fitted thereon a sleeve 21 which supports a roll which is indicated by the numeral 22 and which is of the same dimensions as the roll 10. A belt 23 is trained over the rolls 1() and 22 with its upper stretch travelling beneath the base 1 and its lower stretch travelling beneath a shoe which is adjustably mounted beneath the base 1 as will presently be explained, it being understood at this point that the belt may be rendered taut by adjusting the screw 13 so as to move the bearing member 12 in a forward direction, the screw being provided between its threaded end portions, with a knurled head 24: to facilitate such adjustment of the screw.

The belt 23 will have applied to its outer surface, a coating of any suitable abrading material such for example as sand or garnet, and it will readily be understood that the lower stretch of the belt constitutesthe abrading stretch.

In order that motion may be imparted to the belt 23, means is provided which will now be described.

The means referred to above comprises a shaft 25 which is rotatably journaled. at its ends in suitable bearings 26 upon the opposite side walls of the gear case 3, and this shaft has fixed upon it, midway between its ends, a worm gear 27 which is in mesh with a worm 28 fixed upon the shaft 2 9 of the motor 2, the motor shaft having its rear end extended longitudinally through the gear casin 3 and journaled in suitable hearings in said casing. Wheels 30 are fixed upon the shaft 25 at the under sides of the worm gear 27 and each of these wheels is provided with a rim 31 which is preferably of soft rubber and preferably formed with a number of concave depressions 32 in its surface. As will be observed by reference to Figures 3 and 6 of the drawings, the rims 31 of the wheels 30 travel in frictional contact with the portion of the belt 23 which passes over the upper side of the roll 10 and in this manner motion is transmitted to the belt and roll, so as to effect travel of the belt and cause the lower stretch thereof to act upon the piece of work to be dressed. It will be evident that inasmuch. as the rim 31 of each wheel 30 is of soft rubber and is formed with the depressions 32, these depressions constitute, in edect, vacuum cups which insure of a positive and steady appli cation of power through the medium ofthe rim 31, to the belt 23, and likewise the cups serve to remove particles of material which might otherwise adhere to the surface of the menace belt, and which particles are removed by the abrasive action of the lower stretch of the belt upon the surface of the work. Therefore the wheels 30 and their rims 31 constitute not only means for transmitting motion to the belt, but also as a means for freeing the belt from accumulations which would be liable to impair its efiiciency as an abrading medium,

In order that the lower stretch ofthe belt 23 may be held in snug and flat contact with the surface of the work to be dressed, means is provided for backing this stretch of the belt or in other words for holding it against upward flexing or displacement, and this means includes a shoe which is indicated in general by the numeral 33 and comprises a body plate 3% to the under side of which there is applied and suitably secured, by adhesive or otherwise, a sheet 35 of felt or other material found suitable for the purpose. The plate 3a is of oblong rectangular form and, as will be observed by reference to Figures 1, 3, 4 and 5. extends in a front to rear direction in the space between the rolls 10 and 22 and is of a width slightly greater than the width of the belt 23, the lower stretch of the belt traveling beneath the shoe and in contact at its upper surface with the under surface of the sheet 35, as clearlyshown in Figures 3, a and 5 of the drawings. It will be observed at this point that the under surface of the sheet 35 of the shoe 33 occupies the same horizontal plane as'the under sides of the rolls 10 and 22, so that the lower stretch of the belt 23 is not only held taut through adjustment of the screw 13 and the conseguent adjustment of the roll 22 in a forwardirection and away from the roll 10, but also by reason of the engagement of this stretch against the sheet '35 which is rendered substantially rigid through its attachment to the plate 34.. The plate 34 has formed upon its 7 upper side, near its forward end, a pair of upstanding lugs 36 the upper sides of which" iio are inclined downwardly and forwardly and provided with laterally outstanding tongues 37 which tongues work in grooves 38 provided between spaced ribs 39 formed upon the inner sides of depending side portions or check pieces 40 which are integral with the base 1 and project downwardly therefrom as clearly shown in Figures 1, 3 and 4 of the drawings. Lugs 41 similar to the lugs 33 are formed upon the plate 34 near the rear end thereof and are rovided with outstanding tongues 42 whlch'are inclined downwardly as in the case of the tongues. 37 and are guided in grooves 43 formed between spaced ribs 44- in turn formed upon the inner sides of cheek pieces 1-5 which correspond to the cheek pieces 40, previously described and which therefore, as in the case of the said cheek pieces 40, depend from the opposite sides of the base 1. A pair of ears 46 is formed upon the upper side of the plate 34 near the front thereof and between the lugs 36, and a bearing block 47 is swingingly mounted upon a rivet 48 which extends be-" tween the cars 46, and is provided with a threaded openlng 49 into which is adjustably threaded the forward portion of a stem 50,

adapted to accommodate the end of a nail or any other pointed device whereby the head ,may be rotatably adjusted to correspondingly adjust the stem 50. The stem extends likewise rearwardlybeyond the head, 51 and this portion 'of the stem, at its extremlty, is

.rotatably fitted in an opening 53 formed in an car 54 which depends from the under side of a collar 55 which is pressed or otherwise secured upon a-sleeve 56' which is rotatably fitted on a bolt 57; which is. inserted through anopening in one of the cheek pieces 45 and threaded at its end into an opening in the other cheek The end of the stem 50 which is rotatably mounted in the opening 53, is provided with spaced collars 58 which engage the front and. rear sides of the ear54 s0 as to prevent longitudinal displacement of the said end of the stem 50 in the opening in the said ear and'yet provide for free rotative adjustment of the stem so as to effect longitudinal adjustment of the bearing block 47 and thus, in turn, effect a forward or rearward adust-ment of the plate of the backing mem er or shoe 33. At this pointit will be understood that when the shoe 33 is adjusted forwardly, the tongues 37 and 42' riding downwardl inand being guided by-the grooves 38 and 43, respectively, will effect a downward displacement of the shoe 33, whereas a reverse adjustment of the shoe will result in elevation of the shoe. Therefore the screw stem 50 may be adjusted so as to effect adjustment of the shoe to cause the same to more 'or less firmly bear against the upper side of the lower stretch of the belt 23 and thus maintain this stretch of the belt flat and prevent upward sagging or distortion thereof when the lower or abrading side of the stretch is disposed upon-thelsurface of the work to be dressed. I

From the foregoing description of this embodiment of the invention it will be evident that there has been provided a sanding machine which is extremely simple and compact in its construction and which maybe very conveniently employed in dressing work and in a manner to effect sanding of work more expeditiously than can, be done by hand or by the use of other machines which do not possess the features of the present machine.

V In. the embodiment of the invention illustrated an described, travel is imparted to the belt 23 through direct contact of the yieldwise accumulate upon the abrading surface of the belt will beremoved by suction.

Under some conditions it may be desirable, due to the character of the work to be dressed, or ot er conditions met with, to abrade the surfa e of the work through the medium of a rot ry, roll rather than through the passage of the stretch of an abrading-belt over the work, and the present invention is peculiarly adapted to this adaptation of the machine illustrated inasmuch as, in such event, it is only necessary to remove the front roll 22 and belt 23, and apply a sheet of abrasive material about the surface of the roll- 10, whereupon the machine ma be moved over the surface of the work to. e dressed in the same manner as though the belt were present, the roll, in this instance, acting uponthe surface to dress the same, and the shoe 33 serving as a support for the machine so as to properly position the roll with respect to the surface of the work.

. Having thus described the invention, what shaft and having a yieldable, cupped rim in frictional driving contact with the abrading medium.

2. In an abrading machine of the glass described, a body, an abrading medium opera-,

tivel mounted thereon, a power shaft upon the ody, a wheel driven from the power shaft, and a rim of yieldable friction mate-- rial upon the wheel in direct frictional driving contact with the abrading medium, the said rim having depressions in its friction surface for enhancing the frictional contact between the rimtand the said abrading medium an for removing accumulations from the surface of the said medium through 5110- tion created, by compression'and expansion of the depression bearing portion of the rim.

3. In an abrading machine of the class described, a body, an abrading medium operatively mounted thereon, a motor mounted upon the body, a shaft mounted upon the body counter to the shaft of the motor, a gear upon the second mentioned shaft, a gear element upon the motor shaft coacting with the gear uponthe second mentioned shaft, and spaced friction wheels upon the second mentioned shaft having yieldable rims in direct about the rolls, means for adjusting the last frictional driving Contact With the ab'rading mentioned roll, and friction means upon the 1 medium. body having frictional driving contact with 4. In an abrading machine of the class dethe said abrading medium at its portion 5 scribed, abody, aroll rotatably mounted upon which is in engagement with the first menthe body, a second roll rotatably mounted tioned roll. upon the body in spaced relation to the first In testimony whereof I affix my signature. mentioned roll, an abrading belt trained HAROLD A. SWAN.

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