Abstract: A seeder of the type adapted to be pulled behind a tractor for seeding a field is provided with an extendable and retractable pivoted linkage assembly on each side of the seeder. A marking disk is rotatably mounted on the furthest extremity of the linkage and a hydraulic piston and cylinder assembly is connected between the two links closest to the seeder assembly for extending and retracting the linkage in a horizontal plane. A pair of support plates are secured to the underside of the two bars closest to the seeder assembly for engaging and supporting the other bars in the retracted condition. Another piston and cylinder assembly is mounted on the seeder and operatively engaged with a lever connected to one of said bars of said first pair of bars for pivoting the retracted linkage upwardly to provide clearance between the marking disk and the field.

Abstract: Rocker arms are mounted for pivoting at their centers about a vertical axis on a chassis with the pivot axis in line with a longitudinal slot through which a crank arm projects. The upper end of the crank arm is pivoted to a crank which upon rotation reciprocates the crank shaft vertically. One or more tines project downwardly from the bottom of the crank arm below the longitudinal slot in the chassis through which the lower end of the crank arm projects and within which the crank arm is permitted to oscillate fore and aft during movement of the aerating machine over the turf. A pair of connecting rods are pivotably mounted at one end to vertical studs fixedly mounted to the rocker arm to opposite sides of the vertical pivot axis of the rocker arm on the chassis. The opposite ends of the pair of connecting rods are pivotably coupled to laterally adjacent crank arms and the connecting rods are of equal length to cause the crank arms to oscillate 180.degree.

Abstract: A hollow tine for a self-propelled lawn aeration machine is formed by a U-shaped metal plate having a stud projecting internally of the plate and welded thereto at one end. The U-shaped metal plate has an oblique cutting edge at the end remote from the stud, includes side edges parallel to each other to define a narrow slot extending from the cutting edge to the stud. The cutters where the oblique cutting edges meet the side edges of the U-shaped metal plate are pinched in to reduce the cross-section of the hollow tine formed thereby to facilitate the release of a plug cut from the turf during penetration of the tine into the turf.

Abstract: Paired, side by side sets of upper and lower wheels are connected together and driven by jack shafts pivotally mounted at respective ends to the upper and lower wheels of each set. One common shaft rotatably mounts the upper wheels, and a second shaft mounts the lower wheels for rotation about common axes to effect driving of the upper wheels and lower wheels in unison. The jack shafts joining the upper and lower wheels, respectively, of each set, are angularly offset to achieve desired timing and rotation of the wheels in unison and the sequence in projection and retraction of tines mounted through the jack shafts to the lower wheels of each set. The arrangement insures tine entry and retraction from the ground perpendicular to the ground. It also permits doubling the RPM of the wheels to increase the force driving the tines into the turf. Machine propulsion is effected automatically as a result of driving the tines in the ground and retraction of same.

Abstract: Paired, side-by-side sets of upper and lower sprocket wheels are commonly chain driven at similar speeds. Crank arms are pivotably mounted at their upper ends to the upper wheels of each set and project slidably through cylindrical bushings fixed to journals rotatably mounted to the lower wheel for rotation about the journal axes, radially displaced from the axis of rotation of the lower wheels. Tines are mounted to the lower ends of the crank arms for penetration into and extraction from the turf to aerate the turf. Machine propulsion is effected automatically as a result of driving the tines into the turf and retraction of the same. Holes at different radial positions within the upper and lower wheels permit the crank arms to be mounted to the upper wheels at different radial positions to control the depth of tine penetration into the turf.

Abstract: A hollow post tube 12 is reciprocable on an anchor spike 14 to implement the placement and removal of a sign post. A striker plate 20 located on the bottom of the post tube may be repeatedly hammered down against a ground abutment plate 16 or up against an impact plate 18, both secured on the anchor spike, to drive the anchor spike into or out of the ground. Planar ears 22 secured to the spike below the ground abutment plate prevent the spike from turning in situ, and the post tube and impact plate are cooperably square in section to prevent the tube from rotating on the spike. A sign carrying cross bar 24 is removably mounted in the open upper end of the post tube by a releasable spring detent strap 36 rigidly secured to a mounting tube 34.

Abstract: A kit for a home craftsman or do-it-yourself person to erect a spiral staircase between different floors of a house; the kit including a center column, a set of step-holder brackets for attachment to the column and to one end of step treads, another set of brackets for attachment under the opposite ends of the step treads, templates for cutting out and drilling a set of treads made of lumber for forming steps, a set of posts for forming a spiral bannister, a set of braces and shims for adjusting the distances between the step treads.