US2456217A

US2456217A - Sanding machine

Info

Publication number: US2456217A
Application number: US740924A
Authority: US
Inventors: Linville L Rothrock
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-04-11
Filing date: 1947-04-11
Publication date: 1948-12-14
Anticipated expiration: 1965-12-14

Description

Dec. 14, l1948.

L.. 1 RoTHRocK SANDING MACHINE 8 Sheets-Sheet 1 Filed April l1, 1947 Dec. 14, 1948. 1 L.. RoTHRocK 2,456,217

SANDING MACHINE Filed April 11, 1947 e sheets-sheet 2 mi@ NN.

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8 sheets-sheet v5 Filed April 11. 1947 I 8 Sheets-Sheet 6 L. L. ROTHROCK SANDING MACHINE Dec. 14, 1948.

Filed April 11, 1.947

l.. 1 Ro'rHRocK 2,456,217

SANDING MACHINE Dec. 14, 1948.l

8 Sheets-Sheet '7 Filed April 11, 1947 l.. l.. RTHRocK SANDING MACHINE De. 14, 194s.

Sheets-Sheet 8 Filed April 11, 1947 forney mounted a sprocket chain 46 having rubber cleats or rubber blocks 41 on the outside surface thereof for engaging the workpieces and feeding them through the apparatus. The sprocket wheel 45 projects upwardly into an elongated slot 50 in the bed plate I3, and also the upper portion of the sprocket chain 46 has movement in this slot 50.

Rotatably mounted in

bearing blocks

5 and 56, secured on the exterior surfaces of side members I and l2, is a shaft 51 on which is xedly mounted a sprocket wheel 58 and on which the sprocket chain 46 is also mounted. The sprocket wheels 45 and 58 are of the same size so as to cause the upper portion of the sprocket chain to occupy a horizontal position in the groove 50.

Secured to one edge of the bed plate i3 and to the side plate I2 and rising upwardly therefrom is a bracket 60 having a laterally projecting portion 6| which has a Vertical threaded hole therethrough in which is threadably mounted a shaft 62 having a hand wheel 63 on its upper end. The lower end of this shaft 62 is shouldered (Figure 11) and penetrates an inverted U-shaped bracket 64 and a collar 65 rotatably confines the bracket 64 on the lower end of the shaft 62. The free ends of the inverted U-shaped bracket 64 have xedly mounted therein a shaft 66 on which is rotatably mounted a rubber-rimmed pressure wheel 61 which is adapted to press against the upper surfaces of the workpieces such as 2| and 22 which are being fed into the machine. Welded to the inverted U-shaped member 64 is a T-shaped arm 68 which is mounted for vertical sliding movement in a dove-tailed member 11 welded to the bracket 60.

Suitable legs 69 project upwardly from the table 22 and support a platform 10 on which is mounted an electric motor 1| having

Wires

12 and 13 extending therefrom to any suitable source of electrical energy, not shown. The motor 1I has a shaft 14 extending therefrom on which is xedly mounted a pulley 15 and which has mounted thereon an endless abrasive belt '16. This abrasive belt 16 has abrasive on the exterior surface thereof and is usually sand paper or cloth or emery paper or cloth and the like.

Secured to one edge of the bed plate I3 and to the side plate |2 is a platform 19 having bearings 82 and 83 in which is rotatably mounted a shaft 8| having a pulley 80 thereon on which the abrasive belt 16 is also mounted. The platform 19 has slidably mounted on its upper surface a plate 84 on which the bearings 82 and 83 are mounted, and one edge of this plate 84 has a block 81 affixed thereto in which is rotatably mounted one end of 1 a threaded shaft 88 which is also threaded in a bearing 89 extending upwardly from the platform 19. The threaded shaft 88 has a hand wheel on one end thereof whereby the position of the pulley 80 can be adjusted longitudinally of the machine to take up any slack in the endless ybelt 16.

There is also provided an idler pulley 92 rotatably mounted on a shaft 93 which projects from one side of a vertically disposed bar 94 which is affixed to one edge of the bed plate I3.

Suitable braces

95 and 96 are also secured to the vertically disposed bar 94 and to the edge of bed plate I3 and to the side member I2 for supporting the bar 94.

In order to apply the abrasive belt to the uneven surfaces of a workpiece, certain pressure applying means are provided. It might be pointed out that the workpieces are usually of irregularly shaped molding having projecting ribs 91 and depressions 98 between the ribs and a flexible endless belt is necessary and also suitable pressure applying means are necessary to apply the belt to the surface to ybe sanded while the belt is moving and also while the workpiece is moving at a much slower speed than the belt. It is of course evident that the sprocket chain 46 is travelling at a constant rate of speed and from right-to-left in Figures 1 and 2 and the lower surface of the sanding belt 16 is also travelling in a clockwise direction in Figure 1.

Projecting laterally from bar 94 is a shaft |00 which has keyed thereon by a suitable key |0I a hub member |02. The hub |02 has projecting from one side thereof a portion |03 to which is secured by screws |04 vertically disposed bars |05 and |66. Pivoted on bar |05 by means of bolts |01 and |08 are links |09 and ||0. The vertically disposed bar |06 has pivoted on screws |`|I and I I2, links I I3 and I4, respectively. The free ends of the links |09 and ||3 are pivoted by means of screws |I6 and ||1 to a bar IIB which is secured by any suitable means su-ch as screws ||9 to a vertically disposed bar |20. The lower end of this bar |20 has likewise affixed thereto by means of screws |22 a similar bar |23 having its ends turned rearwardly towards the shaft |0l0 to which the free ends of links I|0 and I I4 are pivoted by means of screws |25 and |26. surface of bar |20 near the lower end thereof is welded a plate |21 as shown in Figure 9, and also riveted to bar |23 is a flattened U-shaped member |28. In the upper end of bar |20 is slidably secured one end of a shaft |30 on which is pivotally mounted a bar |3I which projects downwardly and passes between the flattened U- shaped bar |28 and the plate |21. Disposed halfway between the shaft |30 and the U-shaped bar |28 and welded to the vertically disposed bar |20 is a lug II5. An adjustment screw |2I, having a lock nut |24 thereon threadably penetrates the lug |I5 and the bar |20 and the end of the screw I2| presses against the bar |3I for adjusting the same forwardly to raise the forward end of block |48. The U-shaped bar |28 has passing therethrough a pin I 34 which penetrates a bolt |33 which slidably penetrates the bar |28 and disposed on this bolt I 23 are compression springs I 35 and |36 which tend to center the vertically disposed ybar |3|. The lower end of bar |3| has secured thereon by means of a bolt |40 one-half of a socket I4| and secured to this half socket I4I by means of a screw |43 is another half socket |42. The two sockets confine a ball |45 on the upper end of a stem |46 which has a platelike portion |41 which is secured to a block |48 by means of screws |49.

The block |48 is preferably made of wood to prevent its heating up under the friction of the belt. The lower surface of this block has grooves |5| therein and projections |52 therebetween which are the male portion coinciding with the female portion which is the workpiece 2| or 22 being operated upon. This universal joint is preferable to allow the front end of the block |48 to move upwardly or downwardly to conform to the On the forward disposed above the table and having a pressure applying member adapted to engage the upper surface of the lower reach of said abrasive belt for holding the abrasive belt in contact with the upper surfaces of the workpieces as they are moved along said groove, the lower face of the pressure applying member being grooved to agree with the configurations of the upper surface of the workpieces being passed along said groove, said pressure applying member being mounted for universal movement on said pivoted framework for allowing its lower surface to conform to unevenness in the upper surface of the workpieces, said pivoted frame having a lever arm extending therefrom and a weight adjustable along said lever arm for regulating the pressure of said workpiece, said pivoted frame also having a slidable rod associated therewith and means for securing said rod in adjusted position to hold thepressure applying means out of contact with the abrasive belt when desired, said slidable rod have ing a tension spring associated therewith biased to counteract the weight on said lever to thereby provide a resilient movable mounting for said pivoted framework. v

` 3. In a sanding machine for Ipolishing one side of a workpiece, means for feeding the workpieces longtudinallyof the machine, an abrasive belt extending longitudinally of the machine, an idler pulley near one end of the machine on which the abrasive belt is mounted, a motor driven pulley near vthe other end of the machine on which the abrasive belt 'is mounted, a Second idler pulley disposed a substantial distance above the machine and over which the upper reach of the abrasive belt travels, a pivoted framework mounted at one end above the framework, the other end of the pivoted framework having a pressure applying member adapted to engage said belt and force it into contact with the workpieces as they move longitudinally of the machine, the pivoted framework having extending therefrom a lever arm and a weight adjustably mounted on the lever arm for regulating the amount of pressure applied to the pressure applying member to be in turn applied to the abrasive belt to hold it in contact with the upper surface of the workpieces, the lower surface of the pressure applying member being grooved to conform to the grooves and projections on the upper surface of the workpiece,

a link having one end pivotally mounted to the free end of the pivoted framework and having its other end slidably mounted in a fixed portion of the machine, a tension spring associated with said link for normally urging the free end of the y pivoted framework away from the abrasive belt but not being sufficient to overcome the pressure exerted by the adjustable weight on said lever, and means associated with -said link for engaging the link when the pivoted framework is raised on its pivot to hold the pivoted framework in elevated position whereby its pressure applying member will be held out of contact with the abrasive belt.l i

`-4. In a sanding machine having a table with a` groove extending longitudinally thereof through which workpieces are fed, an abrasive belt for engaging the upper surface of the workpieces as they travel along said groove, an idler pulley near one end of the table, a motor driven pulley near the other end of the table, a vertically disposed bar intermediate the ends of vthe table having an idler pulley on1 its upper end, an abrasivebelt mounted on all of said pulleys, said vertically disposed bar having a shaft projecting to force it into contact with they yupper surfaces of the workpieces being passed along said groove, the free end of the framework having a, vertically disposed member pivoted near its upper end 'on the framework and having its lower end slidably mounted on a transversely disposed bolt, compression springs disposed on said bolt and on each side of the lower end of said pivoted member for allowing lateral swinging movement of saidf pivoted member, the lower end of said pivoted member having a universal joint thereon, a pressure applying member having a bearing extending from its upper surface and secured in said universal bearing, the lower surface of said pressure applying member being grooved to conform to the configurations of the workpieces being passed along said groove, the pressure applyingmember being adapted to engage the upper surface of the lower reach of the abrasive belt for forcing the abrasive belt into contact with q'the workpieces as they travel along said groove,

5. In a sanding machine having means fory feeding workpieces through the machine and anA abrasive belt for engaging the upper surfaces of the workpieces as they pass through the machine, pressure applying means for Aengaging the lower reach of said abrasive beltA for pressing it into contact with the workpieces, comprising aframe.

rpivoted at one end and having a downwardly projecting member pivoted at its upper end in an upper portion of the free end of said pivoted frame, spring means for allowing lateral swinging l movement of the pivoted member transversely of the path traveled by the workpieces, a ypressure member having its lower surface grooved to conform to the grooves in the workpieces being engaged by the abrasive belt, said pressure mem# ber being pivoted to the lower end of the downwardly projecting member and being adapted to engage the upper surface of the lower reach of the abrasive to engage the upper surface of the lower reach of the abrasive belt for forcing the abrasive belt into contact with the workpieces as they travel through the machine, means for applying pressure to the free end of the pivoted frame for in turn applying pressure to the workpiece to force it intol contact with the abrasive belt and to force the abrasive belt into contact with the workpieces passing through the machine, and means for latching the pivoted framework in raised position to hold the workpiece out of contact with the abrasive belt.

LINVILLE L. ROTHROCK.

REFERENCES CITED le of this patent:

UNITED STATES PATENTS Number Name Date 470,794 Shempp Mar. 15, 1892 1,493,779 Humphreys May 13, 1924 1,927,330 Williams 1;.- Sept. 19, 1933 1,961,210 Fenton June 5, '1934 1,978,149 Stevenson Oct. 23, 1934 2,064,476 Johnson Dec. 15, 1936 2,227,865 Scott Jan. 7, 1941-v 2,338,644

Illmer et al. c 'Jan.,i4, .1944A