Abstract: A spark plug having the electrodes composed of twisted stainless steel wire with their spark gap ends frayed so as to give more spark contacting area, reduce heat and eliminate wear on the electrodes, thus giving a stronger, more efficient spark and more efficient combustion of the fuel-air mixture in the cylinders. A sealing means is also incorporated in the interior of the plug to prevent escape of any combustion products. The frayed ends will vibrate during the firing cycle, which will shake off any carbon which may tend to accumulate on them. A modification shows the ends of the wires not frayed but solid and clean cut.

Abstract: A balanced mower head for carrying a plurality of monofilament lines. The mower head is suitable for being mounted on the shaft of conventional rotary mower and includes certain features which particularly adapt the head for universal fit and for replacing the conventional mower blade with monofilament cutting lines thereby substantially enhancing the safety of the cutting operation. The head defines a bore extending therethrough which is proportioned for receiving the shaft which normally carries the blade of a conventional rotary mower. A plurality of line holders extend outwardly from the head body and define at their outboard end portions an opening which is proportioned for receiving a line such that the line extends outwardly from the outboard end portion of each of the line holders to perform the cutting operation upon rapid rotation of the head. Means are provided for generating air currents in a vertical direction during the cutting operation to stand the vegetation up prior to its being cut.

Abstract: An attachment for the lower end of a vertical drive-shaft of a wheel-mounted power mower of the rotary lawn mower type comprises a balanced assembly of centrally-bored shaft-engaging hub together with a plurality of equi-distantly spaced radially extending arms each of which carries a boss or lateral enlargement adjacent its outer end for receiving a quickly and easily replaceable flexible cutting line which projects freely therefrom in the general direction of the arm by which it is carried. The lower end of the vertical drive-shaft of the prime mover of the rotary mower, which ordinarily receives the mid-section of a rigid metallic cutting blade that is sharpened adjacent each of its ends, is attached to the hub of the rotary assembly of the invention, suitable adapter means being provided for accommodating driveshafts of different sizes.

Abstract: An attachment is provided for the end of the drive shaft of the motor of a rotary lawn mower, edger, trimmer or the like which comprises an elongated member that extends transversely of said drive shaft and carries at each end a rigid container having removably disposed therein a spool of non-metallic cutting line which extends from the spool and through the rigid container into the cutting plane, means being provided whereby the spools, which are oppositely disposed with respect to each other, may be easily and quickly made capable of either free movement or secured thereagainst; with the spools capable of quick and easy replacement when such is found necessary or desirable.

Abstract: A vertically extending attachment for the vertically extending drive-shaft of a rotary lawn mower, edger or trimmer comprises a centrally apertured flexible and longitudinally compressible spool which is encased within a rigid cylindrical sleeve of lesser length with a centrally apertured washer at each end which contacts the corresponding ends of the centrally apertured flexible and longitudinally compressible spool. An elongated centrally disposed adjustable bolt extends through the device with its upper end threaded for reception in the usual screw-threaded recess in the lower end of the aforementioned drive-shaft. A heavy duty monofilament or non-metallic cutting strand is wrapped around the aforementioned spool so as to provide at least two free-travelling ends which extend outwardly through relatively short radially disposed tubes which are mounted in evenly spaced alignment with communicating apertures in the sidewall of the rigid sleeve.