US 2142794 A
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Jan. 3, 1939. J, MATTHEWS 2,142,794
SCREENING MACHINE Filed May 5, 1938 5' Sheets-Sheet l wmwzsass INVENTOR Jsse flafzfiewa I BY u :WM M ATTORNEYS Jan. 3, 1939. Y J, MATTHEWS 2,142,794
SCREENING MACHINE Filed May '5, 1938 5 Sheets-Sheet 2 I INVENTOR 5 Jesse flafifiews wn-Nzssgs 2 2 Q g eow (I I 6/? ATTORNEYS Jan. 3, 1939. J. MATTHEWS SCREENING MACHINE 3 Sheets-Sheet 3 Filed May 5, 1938 INVENTQR tlsse .f/Za flhews ATTORNEYS Patented Jan. 3, 1939 UNITED STATES PATENT OFFICE 4 Claims.
This invention relates to an improved screening machine for screening sand and gravel, or
any other screenable material, an object being to provide a construction wherein the material as it is excavated is screened before it reaches the truck or stock pile.
Another object of the invention is to provide in conjunction with a rotating crane, an excavating structure and a screening device worlnng in harmony so that before the excavated material is dumped it is subjected to a screening action, the parts being so arranged that the matter passing through the screen will be discharged at one point and the matter retained by the screen will be discharged at a second point.
A further and more specific object of the invention is to provide a device for screening or re-screening any suitable screenable material with a minimum of handlings of the material.
In the accompanying drawings Fig. 1 is a side view of an embodiment of the invention shown in the position for excavating a given batch of material;
Fig. 2 is a view similar to Fig. 1 but showing a second position of the parts whereby the material excavated is being screened and the finer material discharged at one point and the coarser material taken care of at another point;
Fig. 3 is a view similar to Fig. 2 except that it shows the parts in the second dumping position;
Fig. 4 is an enlarged fragmentary sectional view through Fig. 2, approximately on the line 4-4;
Fig. 5 is an enlarged fragmentary sectional view through Fig. 2 approximately on the line 5-5;
Fig. 6 is a sectional View through Fig. 5, approximately on the line 6-43;
Fig. 7 is a front view of the clam-shell excavatbucket shown in Fig. 1.
Referring to the accompanying drawings by numerals, 4 indicates a bank or pile of sand and gravel, or other screenable material. Hereinaiter when the expression sand and gravel is used it will be understood to include any other screenable material. As shown in Fig. 1, there is rovided a clam-shell excavating bucket 2, which is of the well-known type, and this bucket is manipulated from a car 3 mounted on a suitable tractor d. The parts just described are old in the art and present a well-known crane structure which has a boom 5 adapted to be actuated from the car 3 and in addition adapted to carry certain improved parts as hereinafter fully described.
It will be noted that the screen 6 is pivotally mounted at l on the boom 5 and is connected at 8 to the upper part of the excavating bucket. A control cable 9 passes over a suitable guiding pulley ill and is connected to the screen 6 so as to .5 pull the screen to the position shown in Fig. 1 whenever desired. This cable is sometimes known as a tag line cable or chain and is connected to suitable means on the car 3 which are power operated. It will be understood that the 10 lifting and manipulating cables are connected to the bucket 2 and are operated by power actuated means on the car 3.
When the device is in use the bucket 2 is caused to excavate a quantity of sand and gravel and this 16 sand and gravel is raised to the position shown in Fig. 2, after which the bucket is rather slowly opened so as to discharge the contents therefrom.
As the screen 6 is connected by a pair of cables i l to the point 8, the screen will be swung upwardly 20 to the position shown in Fig. 2 by the time the bucket 2 has reached its proper elevated position. As soon as the parts reach substantially the position shown in Fig. 2', the control cable of the bucket 2' is manipulated to open rather gradually 25 the bucket and the contents will then be discharged on to the screen. The finer matter of the contents will pass through the screen and will discharge on to a stock pile l2 or in a truck as may be preferred. The coarser material will be 30 retained on the screen and will pass down to the screen hopper 13 from which it may be dumped later. In case any of the material catches in the screen and it is desired to screen or dislodge the same, the bucket holding cable is suddenly re- 35 leased and then stopped. This will allow the screen to drop suddenly and then stop. This will give a shaking action to the screen and will also increase its pitch. Usually this is sufficient to take care of any matter lodging on the screen.
It will be understood that when the parts are moved to the position shown in Fig. 2, the boom 5 could be rotated to the desired position before the bucket 2 is opened so that the fine material will drop on the stock pile l2 or on a suitably positioned truck.
Preferably the boom is swung a little further or to a second position so as to be above a gravel stock pile M, as shown in Fig. 3, or above a sec- 5U 0nd truck. The bucket 2 is then lowered and the tag cable 9 is pulled inwardly until the screen is at the angle shown in Fig. 3 or at a similar angle, .as for instance the angle shown in Fig. 1. This will cause all of the coarser material to be dis- 55 charged from the screen and also from the hopper l3.
By this construction and arrangement it will be seen that the material is handled only once and is screened only once. In case it is desired to rescreen the material the same action again takes place either with the same screen or with a finer screen.
Referring to Figs. 4, 5 and 6, it will be noted that the screen 6 is provided with side members l5 and Hi, which may be wood or other desired material, as for instance metal, and which are connected together by suitable cross braces .11 and auxiliary braces 18. A wire mesh screen material I9 is mounted on top of thezbraces 18, as shown in Fig. 6, and extends to the hopper l3. This hopper I3 is open at the bottom except for a screen 28. It will be notedthat thefrontand rear walls 2| and 22 taper or converge toward each other. It will also be noted that the hopper is provided with a top strip 23 having an inclined deflecting plate 24 arranged parallel to the wall 22, whereby an opening 25 is presented. This will allow the coarser material on the screen to pass down into the hopper l3. Ahinge cover 25 is hingedly connected with the plate 24 and rests by gravity on top of wall 2!. This will prevent any of the coarser material from bouncing out of the hopper, but will not prevent the hopper from discharging from the top when the screen 5 is moved to the position shown in Figs. 1 or 3. The cover 25 will swing out of the way by gravity and also by reason of the coarser material striking the same as it flows from the hopper. From these figures it will be seen that there is provided a or rod 2'! which extends through the side members i5 and i5 and to which the tag line chain 9 is connected. The lifting cables H are also connected to this bar as shown particularly in Fig. 5.
At the inner end or the end nearest to the boom 5, there are provided cross bars or braces 28 and 29 which keep the side members l5 and i5 spaced while bolts 33 and 3| act to clamp the side members tightly against the bars. The bar 28 is preferably shapedas a channel iron, as shown in Fig. 6, and may be welded or otherwise secured to the cross braces ll at or adjacent their point of crossing. This provides a desired anchor for the pull rod 32 which extends through the bar 28 and receives a pair of nuts 33. The forward end of pull rod 32 extends through the bar 29 and may be threaded into the split tubular portion or shank 34 which isprovided with lugs so as to receive the respective bolts or rivets 35. The lugs 35 are preferably spaced slightly apart so that when the bolts are tightened the shank 34 will pinch the rod 32 whereby not only will the threads of this rod be held to hold the shank 34 in place but the clamping action mentioned will lock the parts together. The shank 34 is preferably formed integral with an arc-shaped section 31 coacting with an arc-shaped section These arc-shaped sections form a housing for a member 39 which acts as a ball. The membore 3*. to 39 inclusive prevent a ball-and-socket structure and the member 38 could be a complete ball, but as shown particularly in Fig. 5 the two ends are cut away and the central part of the ball member 39 is rotatably mounted on a king pin 48 and held against independent lateral movement by the sleeves 4i and 42 which press against member 39 and against the brackets 43 and 44, which brackets are bolted or otherwise rigidly secured to a bar 45. As shown in Fig. 4,
passed around the pulley 52 or 53.
.1 to secure a second bucketful.
the bar 45 coacts with a clamping bar 45 and clamping bolts 41 and 48. This arrangement, as shown in Fig. 4, causes the bars 45 and 46 to be clamped tightly against corner pieces 50 and 5| of the boom 5. By this arrangement the screen or hinged end of the screen 6 may be clamped to any desired point along the boom. Preferably the clamp is arranged approximately half way between the center and the upper or outer .end of the boom. The pulley I0 is arranged a short distance beneath the center of the boom to guide the tag line chain 9. This chain 9, if desired, may be extended directly to the winding drum 54 in car 3, but is preferably Pulley 52 carries a rather heavy weight 55 which is guided by suitable uprights 56 so that it may move directly-upwardly and downwardly. By this arrangement the winding drum. 54 need not be operated except occasionally. When the excavating bucket 2 is raised to the position shown in Fig. 2 the line I I will be pulled and the weight 55 raised as shown in Fig. 2. When the bucket 2 is released and allowed to move downwardly weight 55 will pull on line I I and cause the screen to swing automatically to the position shown in Fig. 1. From this it will be seen that if desired that part of the winding drum 54 used for winding line 9 could be dispensed with and the line 9 secured to the boom or some stationary part of car 3.
Sometimes it is desired to wash the gravel and sand and .to take care of this situation a pipe or hose 5'! is provided. This pipe extends through the king pin of the tractor 4, as indicated in dotted lines in Fig. 1. This cable also extends upwardlyalong the boom to a point near the top where it extends outwardly sufiiciently to discharge water into the bucket 2 when desired. It will be observed that the hose 5! is provided with a curved end 58 as shown in Fig. 2, so that it will direct the water into the bucket during the discharge of the contents thereof.
From Fig. "l'of the drawings it will be noted that the connection 8 shown in Fig. 1 includes .a cross bar 59 which is bolted or otherwise rigidlysecured, to: part of the bucket structure and to which the cables -II are connected by suitable fittings-50. By providing these two cables and by spacing the same apart there will be no tendency to twist the screen 6 as it is moved from one position to the other.
In operation after the bucket 2 has secured a supply-of sand and gravel it is raised a short distance and then swung until the screen 6 is over the stock pile 3. The parts are then moved upwardly to the position shown in Fig. 2 and the bucket discharged. With the parts in this same position the boom 5 is swung until the screen 6 is over the gravel stock pile M, as shown in Fig. 3. The bucket 2 is then lowered sumciently to permit the screen to swing to dumping position. This completes one screening operation. If. more than one bucketful is desired, the deviceds again manipulated as shown in Fig. This action is continued until the desired supply of screened gravel and sand has been secured.
1. A screening apparatus including a crane having a swingable boom and an excavating bucket, a screen hingedly mounted at one end on said boom intermediate its length, a cable connectingthe free end of the screen to said bucket,
and a control cable extending from the free end of said screen whereby when said bucket is elevated said screen will be swung upwardly to a position inclined from the horizontal and beneath the said elevated bucket so that as the excavated material flows from said bucket it will strike said screen and the fine material separated from the coarse.
2. A screen apparatus including a crane provided with a swinging boom, a screen hingedly connected at one end to said boom intermediate the ends of the boom, means for causing said screen to swing toward said boom, and means for causing said screen to swing away from said boom to near a horizontal position, said lastmentioned means including an excavating bucket, means for raising, lowering and manipulating said bucket and a cable connecting said bucket and said screen.
3. A screen apparatus including a crane provided with a swinging boom, an excavating bucket and means for manipulating said bucket, a screen hinged at one end to said boom at a point spaced from the top thereof, flexible means connecting the outer end of said screen to said bucket but spaced therefrom, whereby when said bucket is elevated to a point near the top of said boom said flexible means will swing said screen to a position below the bracket to catch and screen the material discharged from the bucket, and means for swinging said screen toward said boom for discharging material therefrom.
4. A screen apparatus including a crane provided with a boom, an excavating bucket and means for manipulating said bucket, a screen, a ball-and-socket hinge structure connecting one end of said screen to said boom at a point spaced from the top of the boom, whereby the screen may swing horizontally and vertically, means for dumping material to be screened into the screen when the screen is almost horizontal, and means for swinging the screen downwardly for dumping the same.