A constant-volume metering pump includes a pump body, a solenoid device, and a piston pump inside the pump body. The solenoid device includes an armature, and the piston pump includes a sleeve, a piston, an inlet valve, and an outlet valve. The sleeve includes an inner sleeve bore. The inner sleeve bore conforms with the external surface of the piston and can slide freely. The piston pump divides the interior pump body into a low-pressure space and a pressure feed space. Liquid enters the pressure feed space from the low pressure space through the inlet valve and is output through the outlet valve, wherein the sleeve connects with the armature and keeps synchronous reciprocating motions. The solenoid-driven device drives the sleeve to perform a motion relative to the piston, causing output of liquid. The output quantity of liquid due to such relative motion is defined by the geometric construction.

An accessory for a kitchen appliance, particularly in the form of a measuring cup, for being attached to a cooking vessel, as well as to a correspondingly equipped kitchen appliance, wherein a sensor arrangement is arranged in the accessory and is capable of determining operating states, which are transmitted wirelessly to the kitchen appliance.

A liquid measuring beaker is suitable for measuring an amount of a liquid required in a liquid mixing process. The liquid measuring beaker includes a shell and an adjusting partition. The shell defines a reservoir having a volumetric capacity, in which the shell has a first opening passing through a bottom of the shell. The adjusting partition is vertically movable in the reservoir for adjusting the volumetric capacity, in which the adjusting partition has a second opening passing through the adjusting partition.