Abstract: A dual shaft pan mixer comprises a mixing vessel (1) having a first and a second pan section (3 and 4), a pair of paddle assemblies (10) having drive shafts (13) which are disposed horizontally and in paralllel relationship with each other within the mixing vessel (1) and adapted to rotate in mutually opposite directions, and a drive source (20) for synchronously driving the pair of paddle assemblies (10). The mixing vessel (1) includes a substantially triangular space (22) below an area intermediate the first and the second pan section and displaced out of the loci of rotation of the paddle assemblies (10), and also includes a discharge port (5) which is disposed adjacent to the space (22). The mixer also comprises a rod-shaped vibration generator (30) disposed within the space (22) and extending in a direction parallel to the drive shafts (13).

Abstract: A forced kneading concrete mixer including a or a plurality of mixing members such as paddles or blades disposed at fixed positions within a rotating pan or cylindrical vessel. The mixing member is carried by a support which is movably mounted on a stationary member and which is subjected to a vertical oscillation having an amplitude of from 2 to 5 mm and a frequency of 3500 to 6000 cycles per minute. A fluid charge comprising ingredients to form concrete is mulled and oscillated by the cooperation of the vessel and the mixing member. When subjected to the oscillation, the individual particles of cement contained in the oscillating fluid charge are dispersed and acquire moisture on their surface. The load on the mixing member is reduced inasmuch as the consistency is increased due to a temporary tendency of the charge to fluidize.