Patent GB-470527-A (GB)
Title: Improvements in or relating to vacuum cleaners
IPC: A47L9/19
Filed: 1936-06-15
Abstract: 470,527. Vacuum cleaners. ELECTROLUX, Ltd. June 15, 1936, No. 16650. Convention date, June 14, 1935. [Class 8 (ii)] A vacuum cleaner is provided with a device for indicating the filling of the dust collector, or the clogging of the dust filter, which includes an indicator moved solely in one direction, directly or indirectly, under the action of pressure differences produced by the air circulator and remaining in its set positions until the release or actuation of a re-setting device. In one form, Figs. 2, 3, the rear end of the dust bag 14 rests against a plate 24 supported by springs 25 mounted on the fan housing 26, the plate in turn bearing against the end 28 of a rod 30 slidably mounted in the cleaner casing 10 ; the rod 30 engages the arm 41 of an indicator 40 mounted in a cap 39 forming part of the front fastening of the handle 23 ; the indicator is viewed through a window 42 and may have coloured fields. As the dust bag becomes filled, or the pores become clogged, the pressure inside the bag becomes greater than that in the fan chamber and the bag distends, movement of the plate 24 thus operating the indicator 40; when the cleaner is inoperative, the return movement of the bag does not affect the indicator which remains in its set position. In a modification, the rod 30 carries a plate with coloured fields viewed through a window. The dust bag is carried by a ring 16 the flange 17 of which is embedded in packing 18 which is gripped between the end cap 11 secured by toggle catches and the casing 10 or a reinforcing ring 20 secured thereto. A rod 34 is slidably mounted in the casing 10 and is held in the position shown by the packing 18 pressing on its head 36 ; when the end cap 11 and dust bag are removed, a spring 37 moves the rod 34 to the left and a lug 33 working in a slot 32 in the rod 30 engages the left-hand end of the slot thereby moving the rod 30 to the left and resetting the indicator to zero. In a modification, Fig. 5, a membrane 50 is mounted in a housing 45 formed integral with the reinforcing ring 20 of the casing 10 ; the front of the membrane communicates through passages 70, 71, 74, 72, 73 with the filter space F while the rear of the membrane communicates with the fan space U. When the dust bag fills or clogs the membrane 50 is moved to the right against the action of a spring 59 by the pressure differences set up, and so displaces an indicator sleeve 61 which is viewed through a window 62. When the end cap and dust bag are removed a spring 69 moves a rod 66 to the left and sets the indicator sleeve back to zero. In a modification, Fig. 7, the membrane 50 and indicator 61 are both secured to a sleeve 76 movable on a spindle 77 ; the front of the membrane communicates through a passage 80 and bore 79 in the spindle 77 and a recess 81 and passage 82 in the end cap with the filter space F while the rear of the membrane communicates with the fan space U through a hole 92 in one of the two cylindrical end members gripping the transparent tube 91. A disc 86 is loosely mounted on the spindle 77 and is engaged by a pin 88 secured to the part 76 and carrying a spring 90 which presses the disc 86 against the head 89 of the pin. When the dust bag fills or clogs the parts 50, 61, 76 are moved to the right against the action of a spring 59 by the pressure differences set up, movement of the indicator sleeve 61 being viewed through the tube 91 ; the pin 88 causes the disc 86 to set at right-angles to the spindle 77 and so permit rearward movement of the sleeve 76; reverse movement of the indicator is however prevented by the disc 86 assuming an inclined position on the spindle 77. On removal of the end cap 11 the spindle 77 is moved to the left by a spring 85, the locking action of the disc 86 is no longer exerted and the indicator 61 is returned to its zero position by the spring 59. In a modification, the return spring 85 is dispensed with and the end of the spindle 77 abuts against the end wall of the indicator chamber ; on removal of the end cover the spring 59 acting on the member 76 moves that member and the spindle 77 to the left until the bent edge of the disc contacts the end wall of the indicator chamber, at which time the indicator 61 has returned to its zero position. In a modification, Fig. 8, the indicating device is provided in the end cap and includes a membrane 93 the inner and outer edges of which are secured to parts 94, 95 respectively ; a member 96 is moved to the left by the membrane against the action of a spring 97 and so moves the indicator 99 which is slidably mounted on a rod 98 and is viewed through a window 100. On removal of the end cap from the cleaner casing a spring 102 moves a member 101 to the right, a part 104 thereon engaging a flange 105 on the indicator and resetting it to zero. In a modification, Fig. 10, when the membrane 96 is moved to the left against the action of the spring 97 a pin 108 carried by the membrane acts on a pivotal indicator 111 viewed through a window 100 ; when the end cap is removed from the cleaner casing a member 113 is moved to the right by a spring to reset the indicator to zero. In a modification, Fig. 13, the membrane 116 abuts against the end of the indicator 122 which is thus projected from the end cap by movement of the membrane; the indicator 122 is carried by a membrane 119 which together with the membrane 116 encloses a space 118 communicating through passages 125, 126, 127, 128, 129 with the fan space U, the membrane 116 being acted upon by the pressure in the filter space F. The indicator may be provided with graduated divisions, and friction is caused by a ring 124 ; in this form, the indicator is reset by hand. In some forms the membrane and indicator may be integrally moulded from rubber. Specification 401,195 is referred to.