Abstract: An aerator for lawns and the like has spiders formed of four identically formed members. Each member has a tine on each end, so four members provide eight tines for the spider. The members are relatively narrow, and filler members at each side of the tine members provide stability to the spider. The spiders are carried by a frame, and the frame carries a weight-receiving tray for carrying weight to assure penetration of the tines. Springs carry the tray on the frame so the springs will absorb the energy if the tines engage an impenetrable object.

Abstract: An improved brush attachment (10) includes a frame (12) comprising a semirigid plate (14) and rigid braces (16-24) so that the relative overall stiffness is adjustable in accordance with the contour of the underlying surface. An arrangement of end-to-end, oppositely angled brushes (46-60) is provided on the bottom of the frame (12).

Abstract: There is disclosed a manually powered aeration device having a frame and a removable weight tank which is positioned such that the center of gravity of the weight tank and the aerator cylidner are in substantially vertical alignment.

Abstract: An improved mechanism for connecting a ground-engaging blade to the frame of a vehicle is disclosed which allows the blade to tilt, pitch or angle relative to the frame. The disclosed arrangement includes a pair of hydraulic cylinders which control the tilting or pitching of the blade and a single hydraulic cylinder which controls the angling of the blade. The cylinders are all pivotally connected to an intermediate member which is pinned to the blade and guided through an arc on the frame by a guide bar formed on the frame. A single hydraulic circuit is disclosed which powers the pair of hydraulic cylinders to pitch or tilt the blade relative to the frame. The resulting arrangement is both simplified and relatively stable when compared to prior art structures.

Abstract: A tractor includes front wheels and rear wheels. A three-point hitch connects a yoke to the tractor. The yoke is stabilized by stabilizer arms which are connected under the rear tractor axles and to the frame of the tractor forward of the rear tractor axles. The stabilizer arms lock up the yoke so that it is rigidly fixed to the tractor when an earth working implement tilling the soil is stressing the yoke. The stabilizer arms are connected to the yoke by chain links which permit the yoke to be raised and lowered by the three-point hitch, but which prevent any lateral movement or flexibility to the yoke. This rigidity in part is by having the chain link connection of each stabilizing link straddle the connection of the three-point hitch to the yoke. In addition, the two stabilizing arms are connected by a cross brace which is bolted in place. The cross brace may be unbolted in the event a power takeoff shaft is to be used, which would otherwise be blocked by the cross brace.

Abstract: An archery bow rest shelf portion amounts brackets having upper and lower horizontal arms that respectively mount an arrow holder and an arm rest device for pivotal movement between generally vertical extending positions for engaging opposite sides of the arrow shaft to aid in retaining the arrow in an emplacement position and stabilizing an arrow as it is being propelled by the bow string. The swing arm is generally of a frusto-sector shape with its forward base corner portion pivotally mounted on the lower leg between the vertical position extending above the first leg to a datum position having its arrow supporting, arcuately curved surface forwardly of its vertical position and extending to a lower elevation.

Abstract: Various earthworking machines make use of an oscillatory blade, such as the herein referred to sod cutter. Instead of employing two handles, one of which raises and lowers the blade and the other of which handles, when tightened, maintains the blade at a selected depth, only a single handle is employed. When the handle is manually moved forwardly, the blade is lowered and when moved rearwardly the blade is raised, but when the single handle is moved to the left the blade is locked at the depth that has been determined by the forward movement of the handle, this handle movement to the left camming a shiftable gear rack into engagement with a fixed gear rack to maintain the adjusted blade depth. Handle movement to the right allows a coil spring to disengage the racks. A stop, when appropriately set, enables the selected depth to be re-established after each raising of the blade whenever no change in blade depth is needed.

Abstract: An earth crust breaker drawn by a tool bar on a tractor is provided and consists of an elongated U-shaped frame having an angularly upwardly extending front end attached to the bottom of a vertical member of the tool bar. A post extends vertically from each side of the frame to the free end of a horizontal member of the tool bar. A plurality of specifically placed knife blades extend from the bottom of the frame to penetrate the ground and make slices into the crust thereby chopping it up.

Abstract: A soil cultivator has a new cultivator shank and a new plow blade which has a fixed lock structure. The plow blade is held to the shank by a movable snap action lock mechanism in a working end of the shank. A new method of quickly changing plow blades with a snap action lock in a cultivator shank is also provided.

Abstract: A hoe attachment for a conventional rotary line trimmer designed to cultivate soil when rotated and which is particularly useful for cultivating small areas of soil. The attachment comprises a plurality of downwardly extending arms each having a blade projection at the lower end thereof extending radially inwardly toward the vertical axis of rotation.

Abstract: A method of producing a work surface by producing a reference plane 2--2 and traversing a working tool 104 in a direction generally parallel to said reference plane. So that the required work surface can be a surface other than of flat planar form, the distance of the working tool 104 from the reference plane 2--2 is varied in accordance with instructions from a computer 120 in response to a measure of distance travelled.

Abstract: A corner bracket 20, 120 forming part of a system of corner brackets adapted for mechanically inter-connecting in an air tight manner generally rectangular duct portions 37, 38. A first bracket 12 on the end of a first duct 37 is placed in adjacent, abutting, back to back relationship with a second bracket 6 on a second duct 38 and similarly at all four corners of the duct ends. Tabs 27, 127 which are formed from the corner bracket 20, 120 are located so as to be foldable over the adjacent, back to back brackets so as to mechanically bind the brackets together. The folding operation can be performed with hand tools such as hammers and the like. Using appropriate seals, an air tight, mechanically sound duct joint is accomplished. The brackets and the bracket inter-connection system are particularly suited for use with air conditioning duct networks.

Abstract: A clamp for forming a seal on a pipeline section, the clamp comprising a pair of complementary clamp members to be clamped together, each clamp member having an inner surface with a pair of axially spaced, circumferentially extending circumferential seals, and one clamp member having a pair of circumferentially spaced longitudinal seals which extend axially to bridge the gaps between the opposed circumferential ends of the pair of circumferential seals to define four junction zones where the circumferential seals and the longitudinal seals abut, and retention means at each junction zone to connect the circumferential and longitudinal seals together in the retention zones, and at the same time connect the seals to the clamp member at the junction zones. The clamp includes corner seals to provide back-up sealing for the junction zones. The clamp includes heat protection grooves to protect certain of the clamp seals. The clamp may include a pipe branch to provide a hot tapping facility.

Abstract: A multiple use cultivating tool includes a generally planar rigid blade support defining a plurality of outwardly extending cultivating members and a lower tamping surface. A generally triangular pick blade and a plurality of pointed rake teeth extend outwardly from the blade support in generally perpendicular directions. A straight blade is formed on a portion of the blade support and extends outwardly to form an additional cultivating member. A generally cylindrical handle support is secured to the blade support and extends orthogonally therefrom. An elongated rigid handle is secured within the handle support.

Abstract: A method and structure for environmental control of plant growth in greenhouse conditions. The structure comprises a translucent stressed fabric shell on a base, the shell and base enclosing a predetermined space within which to grow horticultural plants, the shell and base sealing the environment within the space against external environmental air conditions. Temperature, humidity carbon dioxide are monitored and controlled within the space by a microprocessor programmed to provide optimum temperature, humidity and carbon dioxide conditions within the space. The structure and method are ideally suited to nutrient film techniques, wherein nutrient being fed to the plant roots is monitored and controlled by the microprocessor.

Abstract: A launderable cloth-like product for surgical use and method of making same are provided wherein such product has a plurality of layers comprising at least a portion thereof with the plurality of layers comprising a bottom layer and a top layer each made of woven material and the layers are suitably fastened together. The top layer is made with warps and wefts in a plain weave with each of the warps and wefts being made of a blend of natural material and synthetic material and a coating on the top layer defines the outside surface thereof. The coating has hydrophobic properties such that the top layer when new and with the coating thereon is substantially impermeable to water flow therethrough prior to laundering thereof and when subjecting the outside surface to a hydrostatic water pressure generally of the order of 50 pounds per square inch gauge.

Abstract: An auxiliary support for permitting longitudinal travel of transversely elongated agricultural implements comprises a pivoted lifting frame adapted to extend outwardly and downwardly to elevationally raise the implement framework at one side. The outer end of the lifting frame is provided with a wheel aligned in the desired longitudinal direction of travel. An adjustable and removable saddle has an extension that overlies the implement frame to permit interposition of a conventional jack to raise and lower the implement framework as required. The elevated implement framework is held in a travel position by chains extending between the outer end of the lifting frame and brackets attached to the implement framework. A foldable hitch frame can be provided at one side of the implement framework to facilitate towing of the implement in a direction perpendicular to its normal direction of field movement.

Abstract: A game and sport device which can be used to repeatably mold and accurately throw snowballs as launched missiles. It comprises a hollow plastic shaft having a cup used for molding and holding a snowball at one or both ends. Snowballs are held in place by snow compacted into a series of 360.degree. grooves inside each end cup. They are launched into flight at about the zenith of the throwing motion when the force of the throw exceeds the shear force of the snow where it is compacted into the grooves. The widest cup diameter occurs at the cup mouth and the snowballs are discharged from the device as a single mass of material. Two cups each having a different groove pattern, sizes or the like can be provided at opposite ends of the device to allow opportunity for cup selection to compensate for various snow conditions.

Abstract: A device for attaching a working machine to a vehicle in which a heavy weight working machine can be detachably and fixedly attached to the vehicle and a three point link type working machine can also be attached through a three points linking mechanism when the heavy working machine is not attached to the vehicle. The device includes an attachment frame at a rear portion of the vehicle body, and a working machine connecting portion for attaching the heavy weight working machine. Further, a three point link connecting portion for connecting the three point linking mechanism is provided on the attachment frame.

Abstract: A reversible plow comprising a three point hitch, a pivotally mounted tool bar provided with a plurality of adjustable plow gangs, and gauge wheels wherein said tool bar can be shifted from left of center to right of center, and back, by a hydraulic piston such that the plowed ground can be directed in a desired direction. The hitch includes a hydraulic piston and cylinder assembly for shifting the plow frame and tool bar about a central longitudinal axis with respect to the tractor, thereby maintaining the plow in a horizontal position even though one rear wheel of the tractor is in the plowed furrow.