Abstract: A no-till farming apparatus is provided for use with a planter unit which plants seeds as the planter unit is pulled along a predetermined path. The apparatus includes a hiller device coupled to the planter unit. The hiller device is configured to form an elevated ridge including a mixture of soil and a residue remaining from a previous crop in front of the planter unit so that the planter unit plants seeds a predetermined distance below a top surface of the elevated ridge formed by the hiller device. The apparatus also includes a residue cleaning implement located in front of the hiller device to clear at least a portion of the residue in front of the hiller device. In the illustrated embodiment, the residue cleaning implement is pivotably coupled to a support extending in front of the hiller device.

Abstract: A microprocessor-controlled pH and ion concentration meter is disclosed with improved testing procedures. The meter can be tested for excessive internal bias current by measuring the potential (V1) when the meter is connected to a circuit a known voltage (E1) of low impedance and the potential (V2) when the meter is connected to a circuit of the same voltage source (E1) but of known high impedance and having the meter compare (V2-V1) to a preset limit value. The meter can be tested for low internal impedance by further measuring the potential (V4) when the meter is connected to a circuit of a second external voltage (E2) and the known high impedance (R1). The meter then calculates:(V4-V2)and compares that value to preset limits based upon E1, E2 and R1. Such limits can be derived as (Z.sub.o) (E2-E1) / (R.sub.1 +Z.sub.o) where Z.sub.o is the minimum acceptable internal impedance.

Abstract: In accordance with the present invention, a punching assembly is provided which includes a punch slidably mounted in a housing. An air chamber is located between the punch and the housing for air cooling the punch, with means associated between the housing and the punch for automatically transferring air into the chamber in response to the reciprocation of the punch in the housing. The punch has a flange with a sliding fit in the housing to define a piston for changing the volume of the air chamber. In accordance with another feature of the invention, the stripper plate is removable and is automatically locked in place when inserted, i.e., it is self-locking.

Abstract: A trash clearing brush unit for use ahead of a planter unit including a pair of circular brushes rotatably mounted to a vertical support bar and angularly inclined toward one another. The support bar is attachable to a planter unit and vertically adjustable with respect thereto.

Abstract: In accordance with the present invention, a punching assembly is provided. The punch assembly preferably includes a casing or sleeve in which a punch is mounted for longitudinal sliding movement. In accordance with one feature of the invention, a stripper plate is provided adjacent the operating end of the punch. The stripper plate includes a central opening for the punch that surrounds and guides its cutting end. A retaining means is preferably provided to cover a portion of the stripper plate at times to keep the stripper within the assembly until it is to be released.

Abstract: A punch assembly is described for a punch press having a quick tool change capability. The punch assembly comprises a punch sleeve having a punch slidably mounted therein. A tang extends from the sleeve, and a bolt is connected between the tang and the punch. An ejection spring member is mounted between the tang and the bolt for yieldably biasing the bolt in the direction of the punch. An elastic retraction member is mounted in the sleeve for biasing the punch and tang toward one end of the sleeve. Means is provided for retaining the ejection spring and bolt within the punch assembly during partial disassembly thereof so that only the punch is removed during said partial disassembly while the ejection spring and bolt remain in place when the punch is withdrawn after the bolt is unscrewed from the punch. A screw-threaded punch length adjustment platen is threadedly connected between the tang and the punch for adjusting the distance that the punch extends from the punch assembly.

Abstract: A punch assembly for a punch press is described which includes an external housing or sleeve having a punch slidably mounted therein with a spring such as a disc spring for yieldably biasing the punch toward one end of the sleeve and a removable stripper plate mounted on the sleeve in a position around the operating end of the punch. The punch is preferably keyed to the sleeve in more than one location and the stripper plate guides the punch by preventing rotation as well as lateral deflection. A retaining member such as a ring surrounds the stripper plate and can be manipulated manually, e.g. by rotating it, to enable the punch and stripper plate to be ejected by means of a spring.

Abstract: A microprocessor-controlled pH and ion concentration meter is disclosed with improved calibration and testing procedures. For calibration (standardization), the meter stores number pairs (pX.sub.a, E.sub.a), (pX.sup.b, E.sub.b) where the pX values may be pH values (e.g., 4.00 and 7.00) and the E values are expressed in mV/deg K. When multiple standard values are stored, remeasuring one (e.g., replacing E.sub.a1 by E.sub.a2) can be used to update the others (e.g., E.sub.b1 to E.sub.b2) without remeasurement by applying the formula:E.sub.b2 =E.sub.b1 +(E.sub.a2 -E.sub.a1).Additionally, the meter can be tested for excessive internal bias current by measuring the potential (V1) when the meter is connected to a circuit of low impedance and the potential (V2) when the meter is connected to a circuit of the same voltage source but of known high impedance and having the meter compare (V2-V1) to a preset limit value.

Abstract: Apparatus for controlling the speed of a motor which includes a switch connected in series with the motor for controllably conducting an A.C. signal to the motor and means for controlling the switch which includes first means for generating a series of pulses at a frequency which may be varied according to an input signal, second means for generating a pulse once per cycle at a zero crossing of the A.C. signal, third means for generating a pulse at said A.C. signal zero crossing if a pulse was produced by the first generating means during the A.C. cycle immediately preceding said zero crossing, and fourth means responsive to the output of the third generating means for generating a pulse which is supplied to and renders conductive said switch for one complete A.C. cycle.

Abstract: An improved method of potentiometrically titrating a sample to an unknown endpoint or endpoints is disclosed. The method includes delivering a titrant to the sample until an endpoint or endpoints are reached, while continuously monitoring the volume of the titrant delivered to the sample and continuously monitoring the potential of the sample during titration. The improvement in the method is accurately determining the endpoint or endpoints by establishing a substantially constant rate of change in sample potential during titration proximate to the endpoint or endpoints and maintaining the established rate of change in sample potential by adjusting the rate of delivery of the titrant.