US3274712A - Retractable scarifier - Google Patents

Description

Sept. 27, 1966 Q JONES 3,274,712

RETRACTABLE SCARIFIER Filed April 16, 1964 2 Sheets-Sheet 1 FIG-. 2.

INVENTOR. fiW//fl' 6. MOW 55 Sept. 27, 1966 D. c. JONES RETRACTABLE SCARIFIER 2 Sheets-Sheet 2 Filed April 16, 1964 INVENTOR. lV//W' C. /0/V5 United States Patent 3,274,712 RETRACTABLE SCARIFIER Dwight C. Jones, La Habra, Calif, assignor to Earthcavator Company, Inc., a corporation of California Filed Apr. 16, 1964, Ser. No. 360,234 1 Claim. (Cl. 37145) This invention relates to earth scarifiers and particularly to a retractable scarifier of the general type shown in US. Letters Patent to M. C. Davis, et al., US. Patent No. 2,865,117.

This type of scarifier is adapted to be incorporated with a scraper hitched onto the back end of a light tractor and the scarifier is manually shiftable between a downward position in which the scarifier digs into the earth when the scraper is pulled forwardly, and a retracted position in which the scarifier is disposed upwardly out of the way of using the scraper primarily as a dirt scraping, collecting and spreading tool. The mechanism shown in said patent for manually shifting the scarifier between these two positions is located to one side of the vertical yoke which occupies a substantial portion of the frontal area of the scraper and which provides attaching points for the three-point hitch connecting the scraper to the tractor and through which the scraper is pulled and bodily raised or lowered, as desired, by a power take-off on the tractor. The location of the scarifier shifting means a substantial distance from the center of the scraper provides asymmetrical resistance to the stresses set up in the scarifier which renders the latter subject to undue strains in operation.

It is accordingly an object of the present invention to provide a retractable scarifier having manual means for shifting the scarifier between an upwardly retracted position and a downwardly disposed operative position and locking the scarifier in the latter position which applies such restraint to the scarifier in the fore-and-aft vertical plane which bisects the scarifier so as to symmetrically resist the strains imposed upon the scarifier and the scraper supporting the same by engagement of the scarifier with the earth.

It is a further object of the present invention to provide a draft beam with a retractable scarifier mounted thereon, wherein the latter, when in operative position, is locked to said beam at a relatively low central point therein so as to give a direct connection between said beam and said scarifier which is close to the points of the scarifier teeth where these dig into the earth.

A further object of the present invention is to provide a retractable scarifier as aforesaid in which the pivotal mounting of the scarifier on its draft beam is on a transverse axis disposed a substantial distance above the locking connection formed as aforesaid between mid-points of said scarifier and said draft beam at a relatively low level on the latter.

It is still another object of the present invention to provide such a retractable scarifier in which the scarifier is pivotally connected to the aforesaid draft beam along a transverse axis disposed rearwardly from and at a relatively high level with respect to said beam at two widely spaced points and said scarifier, when in operative position is locked downwardly and forwardly with respect to said beam 'by a hook which engages a lower edge of said beam and is located in the fore-and-aft vertical axial plane of the scarifier so as to be symmetrically disposed relative to said points of pivotal connection between said scarifier and said beam.

It is a further object of the present invention to provide such a retractable scarifier in which the mechanism for manually shifting the scarifier between operative and retracted positions is spring counterbalanced to facilitate its being actuated manually.

A further object of the invention is to provide such a scarifier with an adjustable spring counterbalance means whereby the counterbalancing force applied to the scarifier will be suflicient for merely coun-terbalancing the weight of the latter when this weight varies substantially due to varying the number of teeth provided on said scarifier.

The manner of accomplishing the foregoing objects as well as further objects and advantages will be made manifest in the following description taken in connection with the accompanying drawings in which FIG. 1 is a front view of a preferred embodiment of the invention incorporated in a scraper and showing the scarifier in retracted position.

FIG. 2 is an enlarged sectional view taken on the line 22 of FIG. 1.

FIG. 3 is a fragmentary sectional detail view illustrating the full opening of the locking hook by the initial movement of the manual means for shifting the scarifier from its upward retracted position to its downward operative position.

FIG. 4 is a view similar to FIG. 2 with the scarifier shown in lowered operative position.

FIG. 5 is a fragmentary enlarged detail view showing the detail structure of one of the adjustable counterbalancing springs of the invention.

Referring specifically to the drawings, the invention is there illustrated as embodied in a combination earth scraper and scarifier 5 which includes a rectangular scraper bucket 6'having side walls 7 and a back wall 8 connecting rear ends of said side walls, a forwardly inclined scraper blade 9 being mounted on the lower edge of said back wall. A draft beam 10, disposed transversely within said bucket, has its opposite ends integrally united as by welding with forward portions of said walls. Said draft beam includes a heavy cylindrical pipe 11 which is reinforced by angle irons 12 and 13 welded to the front side of said pipe. IFitting front and upper faces of draft beam 10 and welded thereto so as to extend upwardly therefrom is .an arched draft yoke 14, said yoke being symmetrically disposed relative to the fore-and-aft axial vertical plane 22 which bisects the bucket '6. A pair of brace bars 15 are disposed parallel and in symmetrical relation with said plane the upper ends of said bars being welded to the yoke '14 and their lower ends being welded to draft beam 10. Welded to upper portions of bars 15 and extending forwardly therefrom is a pair of apertured bearing lugs 16. Welded to yoke 14 and extending upwardly from the central portion thereof is a pair of apertured lugs 17 through which a pin 18 is inserted. The :lower parallel portions '19 of yoke 14 which are welded to draft beam 10 may be referred to as the feet of said yoke. Welded to beam 10- in outward-1y parallel spaced relation with yoke feet 19 is a pair of hitch attaching lugs 20, said feet and lugs having aligned apertures for receiving hitch attaching pins 21. The combination earth scraper and scarifier 5 is adapted to be drawn behind a Fordson or similar light tractor and for this purpose is connected to such a tractor by an adjustable hitch element 22 which connects to pin 18 and hitch bars 23 which connect to pins 21.

Spaced inwardly from yoke feet 19 and welded to the top face of draft beam 10- is a pair of angle brackets 28 these brackets and said yoke feet having aligned aper-.

tures for receiving shafts 29. Rotatably mounted on each of these shafts is a spring sleeve 30 on which is coiled a heavy spring 31. An end of each of said sleeves disposed adjacent one of said yoke feet is provided with an annular flange 32, said flange having a series of horizontal holes circumferentially arranged therein, any of which is adapted to receive a pin 33 which is horizontally,

slidably mounted in a suitable hole provided therefor in said yoke foot. The end of each spring 31 adjacent flange 32 of the sleeve 30 on which said spring is wound, is fixed to said sleeve by a pin 34 which extends diametrically through aligned apertures in said sleeve and the shaft 29 on which the same is mounted. Integral with each spring 30 and extending upwardly from the inner end thereof is a spring biased arm 35 having an eye 36 formed on its outer end. The purpose of these springs will be made clear hereinafter.

Welded to draft beam 10 in close parallel spaced relation on opposite sides of vertical plane 2-2 is a pair of :lugs 37 having aligned apertures for receiving a pivot pin 38. Welded in a central location on the lower forward edge of draft beam :10 is a striker plate 39. Also welded to beam 10 to extend rearwardly therefrom in relatively widely spaced relation on opposite sides of plane 22 are pairs of lugs 40 each of which pairs has horizontally aligned apertures for receiving a pin 41 these pins in both of said pairs of lugs being in coaxial alignment on an axis which is disposed a substantial distance rearwardly from the pipe 11 of draft beam 10 and a substantial distance above the horizontal plane containing the axis of said pipe.

The combination earth scraper and scarifier includes a scarifier 45 having a hollow scarifier bar 46 which is approximately square'in cross section and has flat walls 47, 48, 49 and 50. Walls 47 and 49 are provided with a series of aligned slots '51 in various pairs of which scariher teeth 52 are mounted. Each pair of slots 51 may have a scarifier tooth 52 mounted therein or certain of these pairs of slots may be left vacant where a particular scarifying job requires the teeth to be spaced apart a greater distance than that between adjacent pairs of slots 51. In other words, the scarifier bar 46 may be operated with a varying number of teeth 52 mounted thereon, the fewer the teeth the greater the distances that adjacent teeth are spaced apart along said bar.

Welded to flat wall 47 of bar 46, so as to extend between pairs of lugs 40, and apertured, so as to receive pins 41 and be pivotally mounted thereon, are lugs 53 each of these lugs having an arcuate face 54 which fits the curvature of pipe 11 and acts as a stop terminating the upward swinging movement of scarifier bar 46 about the axis of pins 41 which determines the upward retracted position of said bar as shown in FIG. 2. Welded upon wall 48 of scarifier bar 46 is a pair of short lugs 55 which are symmetrically spaced on said bar the same distance apart as eyes 36 and are pivotally connected by links 56 and coiled springs 57 to said eyes.

The tension on heavy coiled springs 31 is adjusted in accordance with the number of scarifier teeth 52 mounted on bar 46 so as to yieldably hold said bar in its upward position shown in FIG. 2.

Welded on flat wall 50 of scarifier bar 46 in parallel closely spaced position and equidistant from said vertical plane 2-2 is a pair of hook mounting lugs 60 having aligned holes for mounting a heavy pivot pin 61. A massive hook 62 which is preferably made of steel plate about one inch thick slidably fits between lugs 60 and is apertured to receive pin 61 so as to be pivotally mounted on said pin between said lugs. A stop rod 63- is welded at its ends on lugs 60 to limit the counterclockwise swinging of said hook at its maximum open position (FIG. 3). Welded to a hub portion of hook 62 and extending approximately in the opposite direction from pin 62 than said hook is an arm 64 which is preferably made of steel plate about one-half inch thick, is apertured to receive a pin 65 and has a lug 66 to which one end of a contractile spring 6-7 connects, said spring extending through suitable apertures provided in scarifier bar 46 with the opposite end of said spring hooking onto said bar whereby the spring is concealed within said bar and yieldably urges hook 62 to rotate clockwise into hooking position (FIG. 4).' A pair of quarter inch thick plates 68, lying flat against opposite sides of arm 64, and pivota-lly connected thereto by pin 65, are united by being welded to a stop block 69 with the latter disposed beneath the extremity of arm 64 and between this arm and scarifier bar 46. The plates 68 comprise a link 70 the opposite end of which is pivotally connected to a link 71 which extends between plates 68 and is pivotally connected thereto by a pin 72.

The opposite end of link 71 is pivotally connected by a pin 73 to the upper end of a link 74 the lower end of which extends between lugs 37 and is pivotally mounted on pin 38 provided in said lugs.

Extending through the apertured ends of bearing lugs 16 is a shaft 75 on which a sleeve '76 disposed between said lugs is rotatably mounted, said sleeve having a pair of lever arms 77 welded thereto near the opposite ends of said sleeve so as to extend forwardly therefrom as shown in FIG 2. The free ends of arms 77 are pivotally connected to a pair of off-set links 78 which extend downwardly and inwardly with their lower ends embracing the pivotally connected ends of links 74 and 71 therebetween and being pivotally connected to said ends of said links by pin 73. Welded on one of the lever arms 77 is a hand lever 79.

Operation It is to be understood that the device 5 of the present invention is connected by hitch element 22 and hitch bars 23 to the back end of a tractor, the operator of which is seated just forward of the hand lever 79 so that he may readily reach back and engage this lever with his hand any time he desires to shift the scarifier 45 from its inoperative position as shown in FIG. 2 to its operative position as shown in FIG. 4 or vice versa. To perform the first of these acts, the operator seizes hand lever '79 in the position in which this is shown in FIGS. 1 and 2 and swings it forwardly into the position in which this is shown in FIG. 4. The first result of this movement of hand lever 79 is to shift link 71 in the direction of arrow 80 (FIG. 3) and the first part of this movement rocks the hook 62 into its maximum open position as shown. When the hook 62 is thus brought against stop rod 63, the movement of link 71 is transmitted to the scarifier bar 46 so that the balance of the movement of link 71 in response to the downward and forward swinging of hand lever 79 is to swing the scarifier bar substantially into the downward position in which this is shown in FIG. 4. The friction between the stop block 69 and scarifier bar 46, caused by the pressure of the link 71 against said block during the initial part of this downward swinging of the scarifier bar, causes the hook 62 to continue to be held in its open position practically until the scarifier bar reaches its downward position shown in FIG. 4, whereupon a relaxation of manual pressure on the hand lever 79 reduces the friction between stop block '69 and scarifier bar 46 and permits the hook 62 to respond to the action of contractile spring 67 thereby snapping the hook 62 from its open position, shown in FIG. 3, to its closed position shown in FIG. 4.

It is to be noted that the extremities of hook mounting lug 60 are provided with arcuate faces 81 which fit against the curved outer surface of the draft beam pipe 11 when the scarifier bar 46 is in its downward position shown in FIG. 4. This produces a solid locking of the middle of the scarifier bar to the draft beam 10 against either.

forward or backward movement relative to said beam until the operator, by shifting the hand lever 79 upwardly, withdraws the hook 62 from locking relation with draft beam 10. The latter action is accomplished by the initial upward movement of hand lever 79 from the position in which this is shown in FIG. 4. This movement of course.

shifts the link 71 upwardlywhich pulls upward on the end of link 70 which includes stop block 69, and as the latter underlies the free end of hook arm 64, the upward movement of link 70 swings the hook 62 bodily about its pivotal mounting pin 61 untilthe hook 62 completely disengages striker plate 39 and swings against stop rod 63 so that the balance of the upward movement of link 71 is effective, with the assistance of the heavy coiled springs 31, to swing the scarifier bar 46 from its downward to its upward position as shown in FIG. 2.

The tension of the coiled springs 31 is preferably adjusted in accordance with the number of scarifier teeth 52 mounted on the bar 45 so that the latter will be snugly retained in its upward position as shown in FIG. 2 without the necessity of locking said bar in this position. The spring pressure provided by springs 31 holds the arcuate faces 54 provided on lugs 53 snugly against the draft beam pipe 11 thus placing the scarifier 45 in its retracted upward position so as not to interfere with the various other earth moving operations which the device 5 is provided for performing and which do not involve the use of the scarifier 45.

Included among the advantageous features of the present invention which contribute to its remarkable ruggedness are the following: the symmetrical location of the means for locking the scarifier bar in operative downward position so that it will provide balanced support for all parts of the scarifier 45; division of the draft forces transmitted through the draft beam to the scarifier bar 46 between the widely spaced pairs of pivotal mounting lugs 40 and 53, on the one hand, and a massive central steel hook 62 and means for massively mounting the same on the scarifier bar, on the other hand; providing for the draft beam 10 being engaged by said hook directly in the fore-and-aft vertical axial plane 22 of the invention; providing a substantial spacing between the point of contact between said hook and said draft beam and the transverse axis on which the scarifier bar pivotal mounting lugs 40 and 53 are connected; and the provision of linkage which automatically retracts said hook and maintains it in non-locking position until the moment that the scarifier bar reaches its downward position and then automatically causing the hook to snap into its snug locking position; and the automatic retraction of the hook from its locking position with relation to the draft beam as the first step in the action of the manually operated linkage for returning the scarifier 45 from its downward operative position to its upward retracted position.

While only a single embodiment of the invention has been disclosed herein, it is to be understood that this is for illustrative purposes only and that this specific embodiment is subject to numerous changes and modifications without departing from the spirit of the invention or the scope of the appended claim.

What is claimed is:

A scarifier embodied in an earth scraping tool drawn by a powered tractor, said scarifier comprising: a draft beam adapted to be supported rigidly at its opposite ends on said tool; a scarifier bar having teeth attached thereto, said bar being arranged parallel with and generally rearwardly from said beam; pivotally connected lugs fixed on said beam and said bar at symmetrically spaced points thereon for pivotally mounting said bar on said beam on a transverse axis disposed between said bar and said beam whereby said bar is swingable between a downward teeth extending position and an upward teeth retracting position; striker plate means provided upon a forward lower edge of said beam; hook means disposed symmetrically with the central vertical fore-and-aft axial plane of said tool and pivotally mounted on said bar on a transverse axis between said striker plate means and said hat when the latter is in downward position, said hook means being adapted to hook upwardly over said striker plate means when said bar is swung into its downward position; an arm integral with said hook means and extending rearwardly therefrom above said bar when the same is in downward position; spring means rotatively biasing said hook means and said arm about the axis of their pivotal mounting to move said hook means into hooking relation with said striker plate means when said bar is in downward position; a stop on said bar for limiting rotation of said hook means and said arm in an opposite direction and to a degree slightly past that necessary to unhook said hook means from said striker plate means; a first link, one end of which is pivoted to said arm close to the place where said arm is integrally joined with said hook means and on an axis above said bar when the same is in downward position, said link then extending rearwardly across said bar and having a lug underlying said arm whereby lifting on said link will lift on said arm and Swing said hook means against said stop; a second spring means relatively biasing said bar to rotate the same from its downward position to its upward position when said hook means is swung against said stop; and toggle means for applying power to swing said bar against the action of said second spring means and into its downward position, said means including a second link extending downwardly therefrom and pivotally joined at an obtuse angle at its lower end with the rear extremity of said first link when said bar is in its upward position whereby actuation of said toggle means to push said second link downward rotates said hook means and arm against the action of said first spring means and swings said hook means into engagement with said stop, whereupon further downward movement of said second link swings said bar against the action of said second spring means and into the downward position of said bar where a change thus caused in the angular relation between said links renders the first spring means effective in swinging said hook means upwardly into hooking relation with said striker plate means.

References Cited by the Examiner UNITED STATES PATENTS 1,285,900 11/1918 Bartholomew 172-269 1,854,904 4/1932 Johnson 172-269 X 2,555,555 6/1951 Olson et al 172-269 2,839,851 '6/1958 Geiszler 37--145 2,865,117 12/1958 Davis et a1. 37145 FOREIGN PATENTS 899,731 12/1953 Germany.

352,851 7/1931 Great Britain.

639,151 6/ 1950 Great Britain.

ABRAHAM G. STONE, Primary Examiner.

JOE O. BOLT, WILLIAM A. SMITH III, Examiners.

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