US2261897A - Apparatus for sanding - Google Patents

Description

Nov. 4, 1941. F. w. ADAMS APPARATUS FOR SANDING 2 Sheets-Sheet 1 Filed Aug. 25, 1958 F. W. ADAMS APPARATUS FOR SANDING Nov. 4, 1941.

Filed Aug. 25, 1938 v 2 Sheets-Sheet 2 FLOYD w. ADAMS Patented Nov. 4, 1941 UNITED STATES PATENT- OFFICE APPARATUS FOR SANDING Floyd W. Adams, Metuchen, N. J., assignor to The Celotex Corporation, Chicago, 111., a corporation of Delaware Application August 25, 1938, Serial No. 226,694 4 Claims. (Cl. 51-190),

ing or abrading operation is accomplished by the action of relatively inflexible abrading members, which, although the abrading member itself may not be inflexible, the effect thereof is relatively inflexible due to the fact that where the abrasion occurs the abrasive is backed by substantially inflexible rolls or the like. 7

The invention hereof differs: from the conventional sanding machine in that the machine is so constructed that the abrasive action upon the surface being sanded is what might be termed a flexible abrasive action since the abrasive is mounted resiliently order that the abrasive effect may be self-adjusting depending upon the surface being sanded.

The object of the invention is the provision of a sanding machine which is especially adapted to sanding a surface rather than to sand to a surface, or otherwise expressed, the sanding machine comprising the invention is adapted to sand an approximately equal amount from all portions of the surface rather than to sand unequal amounts from various portions thereof while a surface being sanded with. the ordinary sanding machine, depending upon the irregularity of the original surface, at the high spots receives a relatively heavy sanding with but little or no sanding of the spots in the surfaces which are relatively low.

Other and further objects of the invention are the provision of a sanding machine especially adapted for the accomplishment of the primary object of the invention as aforesaid, which machine shall be simple in construction and economical in operation and which incorporates therein new and novel features in the construction thereof. These other features will become fully apparent upon reading the following description taken in connection with the accompanying drawings.

A particular feature of the invention is in connection with the construction of the sanding roll which is so constructed that the abrasive material acting upon the surface to be sanded is so mounted that the mounting thereof gives or yields according to the elevation of a particular portion of the surface being sanded, so that there is no tendency for every part of the "surface being sanded to be sanded to a uniform plane but instead there is removed from the entire surfacebeing sanded a substantially uniform amount of material.

The inventions hereof are described in the following specification in connection with the construction as illustrated in the accompanying drawings, wherein:

Figure 1 is a side elevation of the complete 7 I sanding machine with unnecessary detailed conillustrated'in Figure 4.

In the embodiment of the invention as illustrated, the sanding machine comprises a novel sander roll construction having top and bottom sanders A. and B. The top and bottom surface sanders are similarly formed and comprise a supporting frame base Ill. The supporting frames of the top and bottom sanders A and B are suitably interconnected by conveyor table frame constructions H and t2. Referring to Figures 1 and 2, the supporting frame ID has mounted thereon an inverted U-shaped yoke l3 for supporting respectively an upper sander roll unit C and a lower sander roll unit D,

The upper sander roll unit C has been illustrated asadjustable while the lower roll D has. been illustrated in a fixed position. It is to be understood, however, as within the scope of the invention, that the. sander roll units may be either'fixed or adjustable; As illustrated, in Figures I and 2, the sander roll unit C is suitably supported from the inverted, yoke l3. by cross members [4 and I5 to which are suitably connected bearing guides I 6. is suitably journaled in a bearing l8 which is adjustably mounted on the guides 16.

The sander roll unit C is adjusted vertically through an adjusting means having a ball and socket joint connection [9 to. the bearing I8. Adjustment of the sander roll unit C is accomplished through an adjusting screw 20 suitably threaded through cross members M of yoke l3 and having on itslower end the ball. portion'o-f ball and socket joint 19 and is actuated through an adjusting wheeIZl. It is therefore apparent A. shaft or arbor l1 chine.

that by actuating the adjusting wheels 2| of the sander roll unit C that the sander roll unit may be vertically raised and lowered to adjust for material which is to be surface sanded having various thicknesses.

As the material which is being sanded is fed through the sanding machine by the conveyor tables I] and I2, 'itis obvious that when the material comes to the lower sander roll unit that means for applying pressure to the material'as it is being sanded on its lower surface is necessary. A simple pressure attachment for the lower sander roll unit will now be described.

Pressure rolls 22 for contacting themateria-l as it enters and leaves the bottom surface sander. unit B are suitably supported on shafts 23 which are suitably pivoted by pressure roll arms 24 mounted on the inverted U' shaped yoke I3.

arbor I! of the upper sander roll unit C. Intermediate the right hand yoke l3 and the sander roll unit C is mounted a drive pulley 46 from which the lower sander roll unit B is driven.

The conveyor belt 3| of the conveyor units H and I2 are actuated from the jack shaft 36 by a belt 41 running over pulleys 42 and 38 which in turn drive the conveyor drive pulley 32 by the belt 39 running over the pulley 31.

The driving means for actuating simultaneously the upper and lower sander roll units C and D comprise a continuous belt 48 passing over the pulleys 46 and pulley 4| to provide for an increase surface contact of the belt 48 over its At the inner ends the arms 24 are pivotally at-.

tached at 25. A pressure roll spring 26 is mount'-' ed at the connecti0n25'and secured at its upper end to vanladjustingscrew. 21. .Thepressure rolls are 'suitablyadjusted on each side of the sanding machine by an adjusting .hand wheel 28.

The conveyor tables II .and' |2 which comprise the mechanism for feeding .the materialthrough the sanding machine are illustrated in Figures 1 and 3; and, in this specific embodiment of the invention the material which is .tobe sanded is in slabs having a relatively fiat surface of large area. The conveyor tables Hand I2 which are suitably .supported byv the framework of the top and bottom surface sanders A and B also serve as support for conveyor shafts '29 of the conveyors entering and leavingjthe sanding ma- As each conveyor is'similan'like reference characters will denotesimil'arparts. i Suitably secured to the conveyor shafts '29 are conveyor rolls or pulleys 30 over which'run conveyor belts 3|. A conveyor drive' pulley' 32 mounted on the conveyor table ll adj'acent the bottom surface sander'B serves to" operate both conveyors. The conveyors are voperatively connected to operate in the same direction-through a belt or similar drive running over connecting drive pulleys 33. 4 v

The driving mechanism for actuating the conveyors for the top and bottom surface sanders A and B and'also' the upper and lower sander roll units vC and D is of conventional construe tion. Referring to Figurel, the various drives will be described. Cross members 34' mounted on the frame I0 of the top surface sander A support bearings 35 in which are journaled drive shafts 36. As the supporting structure for the drive shaft '36 on both units A' and B are the same, like reference characters will indicate similar parts. On the bottom of surface sander B a pulley 31 is secured to the shaft 36. A larger pulley 38 is for decreasing the speed of the feed of the conveyors as they are operated from the same source of power as the sander roll units which are operated at a much higher rate of speed. A belt 39 operatively connects the pulley 31 with the conveyor drive pulley32,

Pulleys 4| and 42 are suitably mounted on the shaft 36: of the topsurface sander A. An idler pulley 43 for the drive of the sand-er roll units C and D is supported on "a'shaft 44 suitably mounted on the conveyor table frame connecting the top and bottom surface sanders A and B and is adjacent to thesander unit D. Referring to Figures 1 and,2, a main drive pulley 45 is secured to the outer end of the shaft or respective pulleys. The belt is returned over the idler 43 which also serves as an idler and belt tightener. It 'is, therefore, apparent from the foregoing description of the drive for the sander roll units 0 and D and from the description of the conveyor drives that as the sander roll units C and D are driven, the conveyor belts are driven but at a reduced speed. To aid in supportin the material as it is fed by means of the conveyor belts 3| of the conveyor tables II and I2. suitable conveyor supporting rolls 49 are mounted on the conveyor table frames and |2.

In order to accomplish the object of the invention which is to provide a sanding machine especially adapted to sanding a surface and particularly a relatively flat surface of large area, a novel sander roll unit is a particular feature of the invention. In order to mount the abrasive material of the sander roll unit, a new and novel construction will be "described with theyaid of Figures 3, 4 and 5. As thesander roll units C andD are similar, like reference characters will indicate similar construction. Each'sander roll unit C and D can be considered asa drum which has a deformed surface and which may be considered as fl'exible or resilient so that -as the sander roll unitsare operated, there isremoved from the entire surface by sanding asubstantially uniform amount of material. The abrasive action of the sanding roll units as they act upon the surface being sanded is what might be termed a flexible abrasive actionfsince the abrasive is mounted either flexibly or resiliently in order that the abrasive effect, depending upon the surface being sanded, may be self adjusting. The term resiliently as used within the scope of the claims covers equivalent construction such as springs or rubber mounting; and, in the particular embodiment illustratedit .refers to a spring covered member upon which an abrasive material is mounted. The term flexibly as used within the scope of the claims is a broader term than the specific term resiliently, and it is used generically to include constructions falling under the term resiliently as well as any loosely mounted abrasive material forming a sander roll unit as illustrated.

In the particular embodiment illustrated in Figures 4 and 5, the sander roll units C and D are suitably formed in the shape of adrum which has a hub50 secured tothe shaft IT. The drum is made up of rings 52 suitably connectedwith the hub 50 by spokes 5|. Bars 53 suitably spaced radially about the rings 52 serve to form the outer surface of the drum to which the abrasive material is attached.

As best illustrated in Figures 3, 4, and 5, a spring steel supporting member 54 forms a resilient mounting for the abrasive which is applied thereto in strips or in any suitable manner.

The abrasive surface formed by the abrasive strip 54 is helically coiled about the outer surface of the drum. It is coiled in such a manner that as the strip advances for the pitch of the helix, there is formed an elliptical surface for each pitch advanced. It is so coiled that at each pitch advance of the helix, a separate elliptical surface is formed which is displaced angularly from the preceding elliptical surface about the surface of the drum, as best illustrated in Figure 5. Preferably, each elliptical surface is secured to a bar 53 at the minor axis of the ellipse by ears 55 which are secured. to the resilient abrasive material 54. Screws 58, rivets, or the like passing through the ears 55 firmly secure the ears 55 to the bar 53.

It is obvious from the foregoing description that a novel sander roll unit has been described which will satisfactorily follow the contours of a relatively flat surface for surface sanding. The helical method of applying the abrasive material also leaves the surface which is sanded perfectly smooth without the usual tell-tale sanding marks. It is further evident from the disclosure that since sanding rolls are usually operated at relatively high peripheral speeds that the centrifugal effect as the drum is rotated will tend to throw the surfaceof each elliptical unit to its maximum diameter while the inner limiting diameter of the sander roll is the point at which the abrasive is secured to the drum for each helical unit. A deformed sanding drum has therefore been provided which has a substantially flexible and helically mounted abrasive surface which is formed by substantially successive elliptical surfaces displaced about the drum; and, the flexible sanding surface so formed has as its maximum diameter substantially the major axis of the ellipse and as its minimum diameter substantially the minor axis of the ellipse. With this construction it is apparent that the abrasive effect of the sanding drum as it is operated is self adjusting depending upon the surface being sanded.

In the operation of the sanding machine, the material is being fed through from left to right, as illustrated in Figure l, and the upper surface is first surface sanded after which the lower surface is surface sanded. The sanding machine is capable of adjustment for various thicknesses of material, and it is also possible to operate the machine so that only one surface is sanded. It is within the scope of the invention that the sander roll units can be operated at any peripheral speed depending upon the material being surface sanded. It is also within the scope of the invention that the conveyors for feeding the material to the sanding machine can be operated at speeds which are relatively low with respect to the peripheral speed of the sanding roll unit, but which are satisfactory for the successive operation of the apparatus. In the preferred embodiment of the invention, however, the periph eral speed of the sanding drum and feed of the conveyors of the sanding machine are within the range of accepted practice.

Although there has been shown in this embodiment a combination of novel features, all

cooperating functionally to provide an improved sanding machine, it is to be understood that the invention, as defined by the following claims, includes the various subcombinations of elements which may be utilized with improved results over the existing structures known in the art.

While the above construction illustrates a preferred embodiment of the-invention, the details of construction described are not essential and may be varied without departure from the scope of the invention as defined in the following claims.

What is claimed is:

1. In a sanding machine adapted for surface sanding, a sanding means in the form of a drum comprising a flexibly mounted abrasive surface for surface sanding, said abrasive surface comprising a plurality of substantially elliptical sanding surfaces and helically formed by a narrow strip of abrasive material secured to the drum about its circumference at substantially the minor axes of the ellipses and in substantially equally displaced steps, and the cross-section through the abrasive strip for each pitch advance of the abrasive strip substantially in the form of an ellipse.

2. A sanding drum for surface sanding comprising a flexibly and substantially helically mounted abrasive surface,'said abrasive surface formed by substantially successive elliptical surfaces angularly displaced about. the drum with respect to each other, whereby a flexible sanding surface is formed having as its maximum diameter substantially the major axis of the ellipse and as its minimum diameter substantially the minor axis of the ellipse.

3. In a sanding machine adapted for surface sanding, sanding means comprising a drum and a flexible sanding element carried thereby, said sanding element comprising a continuous strip of abrasive surface applied helically about said drum, the convolutions of said strip spaced from each other, the cross section of said strip in each convolution substantially in the form of an ellipse, and said strip in each convolution secured to said drum substantially in the region of the minor axis of its elliptical form leaving the remainder of the strip in each convolution unsupported, the successive convolutions of said strip having their major axes angularly displaced about the drum with respect to each other, whereby the abrasive surface of the sanding element is flexibly conformative to the surface of the material being sanded.

4. A sanding drum for surface sanding comprising a flexibly and substantially helically mounted member having an abrasive surface, said abrasive surface. formed by a plurality of successive substantially elliptical surfaces angularly displaced about the drum with respect to each other, said member secured to the drum only in the region of the minor axes of the elliptical surfaces, whereby a flexible sanding surface is formed having as its maximum diameter substantially the major axis of the ellipse and as its minimum diameter substantially the minor axis of the ellipse.

FLOYD W. ADAMS.

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