US2218874A - Sanding machine - Google Patents

Description

Oct'. 22, 1940. E. c. CLARKE SANDING MACHINE 2 SheetsSheet l Filed June 26, 1939 x Rm. RN Q :1: m www@ i NMM\ m.\ WN wm NN W W :iw: m@ n.hw www ohw uw ,m |Hw mw .QN u.\\- JAN NM. E mv w .@.MI .o MI M MY M. N EN. UQ Nvldf NM ma Q .mv QN. Nv. \ma Vv, MK n. m.\ f A mw N l... l w b mm. .Q .9 \N\Fu, kw 11m am. M. .ww I \V. BM. #IT mw .we .El G

Oct. 22, 1940. E. c. CLARKE SANDING MACHINE 2 Sheets-Sheet. 2

Filed June 26, 1939 Patented Oct. 22, 1940 SANDING MACHINE.' e

I Edmund C. Clarke, Jacksonville, Fla.

. Application June 26, 1939, SerialNo. 281,239

4 Claimsf 'chine of the continuous belt type, which may be.

readily adjusted withrespect to aworking plane. Yet, a further object.' is to providea sanding machine of the endlessbelt type, wherein the motor drive is, ,always connected tofthe sanding belt, irrespective of the adjustment of the latter.

Other objects and advantages orfthis invention ywillappear from thefollowing description taken in` connection .with the vaccompanying In thedrawings, wherein like reference characters indicate corresponding parts in the vvarious figures:

Y I Figure l is a front elevation of asanding machineof the endless belt type, showing apreferred embodiment incorporating features of thev present inventive concept;

Figure 2 is a plan view of the device in Figure 12' Figure 3 isa partial vertical cross-section sub-y stantially on the line 3-3 of Figure 1, showing the power drive;

Figure lisa view substantially along the line 4--4 in Figure l, showing the opposite end support Vfor the continuous belt;v

Figure 5 is an enlarged detail transverse section along the line 5-5 in Figures l and 2;

Figure 6 is an enlarged detail substantially on the line 6-6 of Figures l and 3.

Figure '7 is a partial plan view'showing the adjustable arrangement of the pulley 2|.

Considering the drawings in greater detail, the device includes a table I0 arranged to support the entire apparatus. At the opposite ends of the table are mounted supporting brackets II and I2, which are substantially ,H-shaped in transverse cross-section, as clearly seen in Figure 6, and which are rigidly secured to the table by appropriate fastening means I3. Each bracket carries at its outer end a bearing structure I4 arranged to provide a pivotal mounting means for the opposite ends of the endless belt.

' Intermediate the supports is arranged a table I5, which is adjustable with respect to the support I0, and which is of sufficient width to serve both as a flat surface for the upper moving strand I6 of the belt I'I, as well as a supporting surface for, articles being sanded. This table has an enlarged boss I8,4 from which extendsvdownwardly a leg I9, arranged to adjustably support the table with respect to the mechanism. The endless belt I'I extends about a driving pulley 20 pivotally mounted upon the bearing |4 at the power end of the device, and upon 4a similarly arranged pulley 2| mounted at the opposite end of the device. The belt I'I has its upper strand I6 extending between these pulleys as well as the lower `strand or section 22, which normally extends a short distance above the supporting table II).l f

As Viewed in Figure 4, the left-hand pulley 2| is rotatably mounted upon a shaft 23, which in turn, is secured within a bearing 2t.` The bearing is secured upon an outwardly extending arm rof a cup-shaped bearing and supporting element 26. The latter encompasses the bearing I4l and isysecured thereupon by pin 2l and its 'securing means 28, for oscillating or rotary'motion.

A similar mechanism is mounted at the opposite endv of .thetable I0 and comprises an oscillatable arm 29 secured by cup-shaped bearing member 3D uponathe-'bearing I4, and'secured thereto by the headed pin 21 and securing means 28. The arm 29in this case carriesa similar bearing 24".

In order to'keep these arms in appropriateV positionand at the same time allowingior adjustable positioning of the endless sanding belt, a double ended@ yoke or linkl 3| is secured with relation to theshaits 23 and 23 of vthesanding machine. The link is biiurcated at each end, and as clearly observed in .Figures 2' and 6, the bifurcated yoke portions 32 and 33 each have a bearing element 34 and 35 concentric with axis of shaft 23. The opposite end of the yoke is bifurcated with arms 36 and 31, similarly supporting bearingelements which are concentric with the shaft 23. In view of this arrangement, it will be appreciated that movement of the shaft 23' yabout the ,center 2l' of bracket I 2 will also result in `a similar movement of shaft 23 about the axis 21 of bracket II. As a result of this arrangement, it will be observed that the endlessbelt may be raised and lowered so that its upper andlower strands move parallel away from or toward the table l0.

The table I5 previously described has its leg I9 passing through an aperture in the enlarged boss 38, carried by the yoke 3|. A set-screw 39 locks the leg I9 so as to maintain the belt I'I in definite relationship to the table.

The power drive for the sanding mechanism comprises a motor 43, mounted upon a shelf 4|,

' aperture 5 in the shaft 23.

which is in turn, secured upon the bearing shell 30. A change speed pulley 42 has an endless belt 43 carried thereon, and arranged to engage with a driving pulley 44, which latter turns on shaft 23 and serves as. the power drive for the vsanding mechanism by way of pulley 20.

As a result of the construction thus far described, whenever the sanding belt is raised or lowered with respect to the table, a motion of the axis 23 about its support axis 21 will take place, with the axis 23 moving in a similar manner. The motor 40 will also move about the pivot 21 of bracket l2 in a clock-wise direction at the same time as does the shaft 23.

For the .purpose of accomplishing this movement in a controlled and regulated manner, and at the same time rendering the mechanism suitable for locking or holding the sander in definite spacing with regard to the support Il), a Vernier mechanism is provided.

This latter mechanism includes a U-shaped element 45 pivotally supported at 46 upon the bracket l2. 'A screw-threaded rod 41 carries a hand-wheel 4S at its outer end and is rotatably supported in the U-shaped member 45 and limited as to aXial movement thereof by means of collars 119. This shaft passes through a screw-threaded The result obtained by this construction is that the turning of the hand-wheel in a clock-wise or counterclock-wise direction results in a movement of the shaft 23 to a determinate position removed from the position shown in Figure 1, and comprising an arc with axis 21 as a center.

In order to limit axial movement of the shaft 23 a set-screw 5| is arranged to ride within the slot 52 cut in this shaft, as clearly observed in Figure 6. This will maintain a driving end of the sanding belt in fixed relation with respect to the remaining parts of the apparatus, it being'observed that the pulley 2U and pulley 44 are secured to a housing which is freely rotatable on the shaft 23, the latter serving as a bearing support for these elements.

In order to render the belt readily replaceable, the pulley 2l is adjustable. 'I'he bearing device 52 secured to a rod 53, which latter has the handwheel 54, provides the means for shifting the axis of the pulley 2| so that the belt may be replaced. The rod 53 is threaded and rides through a threaded boss 55 carried upon the yoke 3|.

This arrangement is primarily to make the belt track evenly on both pulleys. It will also be noted that the table I serves to tension the sanding belt.

Although a preferred embodiment of this invention is illustrated and described, variations within the true spirit and scope of same are to be determined by the appended claims.

What I claim is:

1. A sanding machine comprising a table base, two pedestals fixed on said base, each of said pedestals having a bearing, a bracket oscillatably mounted on each pedestal bearing, a shaft carried by each of said brackets parallel with each other and to the table base, pulleys mounted on said shafts, an abrasive belt mounted on the pulleys, a connecting rod pivotally connected at each end to one of said shafts and means associated with one pedestal and its associated shaft to angularly adjust said shaft with respect to the pedestal bearing whereby the space between the lower reach of the abrasive belt and the table base can be regulated.

2. The structure of claim l in which one of the brackets is formed with a motor seat, a motor on said seat and power transmission means between the motor and the pulley carried by the 'same bracket.

bracket formed with a cup-like part to seat on the drum and having a depending arm angularly disposed toward the pedestal, a shaft carried by the depending arm of each bracket and extending under and clear of the pedestal, pulleys on each shaft, an abrasive belt mounted on said pulleys, said belt and pulleys mounted clear of the pedestals, a connecting rod having bifurcated ends, said bifurcated ends pivotally engaging the respective shafts and Vstraddling the arms of said brackets I under the bearings, a motor mounted on one of said brackets, power transmission means between the motor and the pulley carried by that bracket and means carried by one pedestal whereby the brackets can be angularly adjusted and the space between the lower stretch of the belt and the table base regulated. f

EDMUND C`. CLARKE.

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