US 2792199 A
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May 14, 1957 M. BECKER ETAL DUST COLLECTOR 2- Sheets-Sheet l Filed Dec. 15, 1955 ullll lll? M4 wwf May 14, 1957 Filed Dec, 15. 1955 E. M. BECKER ET AL DUST COLLECTOR 2 Sheets-Shag@ 2 Ahum x M INVENToRs Mez. .MBE MUD Rey/nouv E. eacfrr/ Ice Patented May 14, 1957 DUST COLLECTOR Earl M. Becker and Raymond E. Brochetti, Pittsburgh, Pa., assignors to Mine Safety Appliances Company, Pittsburgh, Pa., a corporation of Pennsylvania Application December 13, 1955, Serial No. 552,364
7 Claims. (Cl. Z55-50) This invention lrelates to dust collectons of the type used with drills that form bolt holes in mine roofs, so that the rock dust falling down out of the holes can be caught and carried away.
It is among the objects of this invention to provide a dust collector which is supported by the drill steel itself, which is simple in construction, which is easy to apply to the drill steel and remove therefrom, and which can accommodate drill steels of different diameters.
In accordance with this invention, a vertical sleeve is provided with a downwardly tapered inner surface that is slidably engaged by a plurality of laterally spaced clamping shoes that extend down below the sleeve. The inner surfaces of the shoes are curved transversely to fit around a drill steel extending up through the sleeve. A coil spring encircling the shoes below the sleeve is compressed between it and supporting means projecting laterally from the lower ends of the shoes. This spring urges the shoes downward in the sleeve to move the shoes toward eachother so that they will frictionally grip the shoes and steel tightly enough to support the sleeve. Above the sleeve there is an open top dust receiver that has an opening in its bottom which permits the drill steel to extend up through the receiver. The receiver is supported by the sleeve through a bearing that allows the sleeve to rotate with the steel while pressing the top of the receiver up against the roof. As the drill is fed upward, it slides up through the sleeve and receiver.
The invention is illustrated in the accompanying drawings, in which Fig. l is a side view of our dust collector, partly broken away;
Fig. 2 is a horizontal section taken on the line II-II of Fig. 1;
Fig. 3 is a central vertical section; and
Fig. 4 is a fragmentary view, similar to Fig. 3, of a modification.
Referring to Figs. 1 and 3 of the drawings, a cylindrical dust receiver is formed from a rigid bucket 1 having a bellows type sealing gasket 2 fastened around its top for snugly engaging the roof 3 of a mine around a hole 4 that is being drilled up into the roof by a drill 5 mounted on the upper end of a drill shank 6. The drill and shank will be referred to herein as a drill steel. The bottom of the receiver has a central opening through it, through which a tube 7 extends. The tube is welded to the bottom of the receiver. lt projects a short distance below the bottom, but extends a con siderable distance up into the receiver. Mounted on the upper end of the tube is a sealing cap 8 of rubber or the like, provided with a central hole for the drill steel. A clamping 1aand 9 holds the cap on a ring il) that is rotatably mounted on the upper end of the tube. The cap, which snugly engages the drill steel, defiects falling rock dust out away from the top of the tube and down into the receiver around the tube.
The dust receiver is supported by a sleeve 12, the
upper end of which supports a circular friction bearing 13 that engages the bottom of the receiver around the lower end of tube 7. The tube keeps the bearing centered against the bottom of the receiver. As shown in Fig. 2, the sleeve below the bearing is rectangular in horizontal section. It has two parallel sides, between which there are two downwardly and inwardly inclined sides. Engaging the tapered inner surface of the sleeve is a pair of laterally spaced shoes 14, one shoe being slidable against each inclined side of the sleeve. The inner or opposed surfaces of the shoes are curved transversely to tit around the drill steel between them. The shoes are drawn down in the sleeve, to cause them to be moved toward each other and tightly engage the drill steel, by a coil spring 16 that encircles the shoes below the sleeve. This spring is compressed between an outwardly projecting flange 17 secured to the bottom of the sleeve, and similar anges 18 secured to the lower ends of the shoes.
The shoes should engage the drill steel and sleeve i. e. be wedged in between them, tightly enough to prevent the dust collector from sliding down the steel when the top of the receiver is pressed against the mine roof. On the other hand, the engagement should not be so tight as to interfere with sliding of the drill steel up through the shoes as the drill advances. If the shoes tend to bind on the drill steel, they will be moved upward with the steel and that will release them from it momentarily. Because the shoes tightly grip the drill steel, they and the sleeve will rotate with the steel while the sleeve and bearing 13 push the receiver up against the mine roof. As the drill steel rotates, the rock dust from the hole descends and falls into the receiver. After the hole has been completed, the operator pushes up on shoe ilange 18 to permit the shoes to separate so that the drill steel will slide down freely. The dust receiver is emptied after each hole is drilled.
In the modification shown in Fig. 4, the central tube 21 is secured to the top of the sleeve 22 which contains shoes 23 that grip the drill steel 24. The tube extends up through bearing 26 and the bottom of receiver 27, which has a exible cup-like sealing ring 28 mounted on its upper end for engagement with the mine roof 29. Tube 21 extends up through an outer tube 31 that is welded to the bottom of the receiver. The two tubes are spaced apart by upper and lower bearings 32. A ilexible sealing cap 33 is rigidly mounted on the projecting upper end of the inner tube, where it` is held by a clamping ring 34. The cap has a depending skirt 35 that overlaps the top of the outer tube to prevent rock dust from falling between the tubes. The top of the cap grips the drill steel and turns with it and the inner tube.
According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.
1. A dust collector for use with 'a drill steel drilling holes up into the roof of a mine, the collector comprising a vertical sleeve provided with a downwardly tapered inner surface, a plurality of laterally spaced clamping shoes in said sleeve slidably engaging its inner surface and extending down below the sleeve, the inner surfaces of the shoes being curved transversely to tit around a drill steel extending up through the sleeve, supporting means projecting laterally from the lower ends of the shoes, a coil spring encircling the shoes below the sleeve and compressed between said supporting means and the sleeve for urging the shoes downward in the sleeve to cause them to frictionally grip the sleeve and steel tightly enough to support the sleeve, an open top dust receiver above the sleeve and having an opening in its bottom permitting the drill steel to extend up through the receiver, and a bearing between the sleeve and receiver for supporting the latter and allowing said sleeve to rotate with the steel while pressing the top of the receiver up against the roof.
2."A dust collector according to claim 1, in which said spring-supporting means are flanges pl-ojectingout Wardly from the lower ends of the shoes.
3. A dust collector according to claim 1, in which said bearing is secured to the top of the sleeve and rotates With it against the bottom of said receiver.
4. A dust collector according to claim l, including' a VY\vertical tube extending from within said bearing up through said receiver opening, and a ilexible sealing cap mounted on the upper end of the tube and adapted to engage a drill steel extending therethrough.
5. A dust collector according to claim 4, in which said tube is rigidly connected to the bottom of the receiver and centers the bearing against said bottom.
6. A dust collector according to claim 4, in which said tube is rigidly connected to the top of the sleeve and rotatable in the receiver.
7. A dust collector according to claim 4, in which said tube is rigidly connected to the top of the sleeve and rotatable in the receiver, and a second tube encircles said tube and is rigidly connected to the bottom of the receiver, said cap overlapping the upper end of the second tube.
References Cited in the file of this patent UNITED STATES PATENTS