Abstract: The disclosed subject matter relates to extracorporeal blood processing or other processing of fluids. Volumetric fluid balance, a required element of many such processes, may be achieved with multiple pumps or other proportioning or balancing devices which are to some extent independent of each other. This need may arise in treatments that involve multiple fluids. Safe and secure mechanisms to ensure fluid balance in such systems are described.

Abstract: An improved, large capacity, self-propelled, walk-behind power tool, such as a lawn mower, employs a parking brake apparatus which is operative to effectively brake the drive wheels of the tool. The described apparatus is activated by a foot pedal and employs locking fingers having a cooperating lost motion coupling which relieves having to maintain close tolerances for the apparatus during manufacture.

Abstract: A large capacity, self-propelled walk-behind power tool, such as a lawn mower, employs gear-operated transmissions for independently driving each drive wheel. The transmission output shafts connect directly with the drive wheels, and clutch elements for use with the respective transmissions operably engage an input pulley to the transmission rather than an output pulley. The drive wheels are directly connected to the transmissions and the location of the clutching elements is within the periphery of the respective belts. The drive assembly is enclosed by the drive deck.

Abstract: A safety cut-off system prevents the running of a motor of a self-propelled lawn mower having left and right drive wheels, and forward and reverse gears. The safety cut-off system includes a first forward presence lever manipulatable, by an operator, between an ON state and an OFF state, wherein the forward presence lever is biased to the OFF state, and a reverse presence lever manipulatable, by an operator, between an ON state and an OFF state, wherein the reverse presence lever is also biased to the OFF state. A preventing element, which is responsive to the forward and reverse presence levers, is provided for preventing the motor from running, when the lawn mower is in neutral or a forward gear and neither the forward presence lever nor the reverse presence lever are in the ON state, and when the lawn mower is in a reverse gear and the reverse presence lever is not in the ON state.

Abstract: A large capacity, self-propelled walk-behind power tool, such as a lawn mower, employs gear-operated transmissions for independently driving each drive wheel. Control handles are connected to idler pulley levers and brake levers to control the movement of the driving wheels. A constant input rate to the control handles results in a variable output rate to the idler pulley levers and the brake levers.

Abstract: A blade brake assembly is provided for use with a lawn mower having a self-propelled power deck with a pair of drive wheels and a mower deck supporting at least a mower blade driven by the power deck. In order to change the cutting height, the mower deck is pivotable with respect to the power deck. The blade brake assembly includes an actuator mounted to the power deck and shiftable in response to a brake command by an operator, a band brake operatively coupled to the mower blade, a center pivot mounted on the mower deck and fixed with respect thereto, and a pivot lever pivotally mounted on the center pivot and having a first end pivotally connected to an end of the actuator. Furthermore, a link member is pivotally connected at one end thereof to a second end of the pivot lever, opposite the first end, wherein the center pivot is intermediate the two ends of the pivot lever, and wherein the link member is connected at the second end thereof to the band brake.