Patent GB-882783-A (GB)
Title: Improvements in and relating to concrete mixers
IPC: B28C5/18
Filed: 1959-11-10
Abstract: 882,783. Concrete mixers. DURST, F. Nov. 10, 1959 [Nov. 10, 1958; Dec. 12, 1958; April 14, 1959], No. 38081/59. Class 86. A concrete mixer Figs. 1, 2 has a rotatable pan 20 mounted on a shaft 15 driven by an electric motor 14 through reduction gearing 13. A plate 12 secured to the top of the reduction gear casing carries three uprights 27, 28, 29 to which is detachably secured a mounting plate 19 carrying the agitating apparatus which comprises two blades 33, 34 freely rotatable by the action of the materials about an axis at 32 parallel to the axis of the drum, a fixed scraper blade 35, and a blade 36 freely pivoted on a shaft 38 rigidly secured to the mounting plate 19. The mounting plate 19 also has deflector plates 39, 40 for directing materials into the apertures 41, 42. To discharge the mix, the motor, gearing, drum and agitators are mounted for tilting as a unit by means of a hand lever 30 about a horizontal shaft 6 forming part of a wheeled frame 1. In the mixing position the assembly is maintained at a small angle to the vertical as shown in Fig. 1, by stops 44, 45, Fig. 2. The travel in the tilted position is similarly limited. The motor may remain running throughout the mixing, tilting discharging and charging cycle. When the mixer is in operation is is supported by two pivoted legs 9 which may be swung upwards for travelling, and by a wooden block or other like support 10. In a second embodiment, Figs 3 and 4, the frame carries also a container 46 which is divided into three compartments 49, 50, 51. Compartment 49 is for cement and has a sloping floor discharging through a slot 52 closable by a flap 53 into a gauge-box 59. Compartment 50 is for aqueous solution or suspension of a concrete reinforcer, which is pumped by a pump 69 through a pipe 68 to a three-way cock 67 which is operated by a hand lever 71, Fig. 5, in the position as shown the improver is pumped into a measuring container 65 on the mounting plate 19. When the required quantity has been pumped into the container 65 the lever 71 is depressed, actuating the valve 73 to discharge the contents of container 65 into the mixing drum and operating the cock 67 to divert the liquid back through pipe 70 to compartment 50; the bulk of improver therein is thus agitated. The third compartment 51 contains water only which is delivered by pump 76 to the mixing drum through a pipe 77 and regulating valve 78 which is adjusted so that the exact quantity of water required is delivered during the mixing period. The mixing unit is tiltable as before about a shaft 6 which is supported at one end by a leg 9a which can be swung up for travelling; The handle 30 is formed as a loop and has a prolongation 84 which ensures that the motor does not hit the ground if the machine should tilt while the leg 9a is in the travelling position. A press-button switch 87 switches on the mixing motor 14 and the pump 76; a time switch (contained in a compartment 85 in the container 46) switches them both off after the predetermined mixing period. When the mixing unit is tilted a lever 90 actuates a switch 89 which switches on the motor 14 during the emptying period; the switch 89 also breaks additionally the circuit to the pumps 76, 80 that its operation is prevented. When the mixing unit is returned to the mixing position, the motor 14 is switched off until the switch 87 is again actuated. The various pipes and ducts are made flexible to accommodate the tilting movement. A third embodiment, Figs. 6 and 7 (not shown) resembles the first embodiment but is provided with an internal combustion engine mounted on the frame and driving, through a belt or chain, a bevel pinion which is rotatably mounted about the tilting axis and drives the drum through a bevel gear ring. In a fourth embodiment, Figs. 8 and 9 (not shown) the motor 14 of Fig. 1 is removed to a position on the side of the reduction gear and a water pump is mounted on the bottom thereof, pumping water from a static container to the mixing drum through a regulating valve. A detachable axle and wheels may be provided. In a fifth embodiment, Figs. 10 and 11 (not shown) the motor or engine is mounted on the frame at the level of the tilting axis and operates the reduction gear through a flexible or universally jointed shaft. One of the agitating blades is in the form of the double-edged comb, adapted to break up agglomeration of sand.