Vacuum cleaner

Abstract: A vacuum cleaner comprises a dust sensor(6) which constitutes a light emitting device(61) and a light receiving device(62) which devices(61,62) are provided at predetermined positions of a suction nozzle(4) or a suction pipe(2) in a condition that both devices(61,62) oppose to one another in a direction which crosses a dust suction direction by a predetermined angle, a spacer member(72) is positioned at a predetermined position accurately of the suction nozzle(4) or the suction pipe(2) by an engagement of a second projection member(71a) and a second concave section(72c), and each device(61,62) is positioned accurately to the spacer member(72) by an engagement of a first concave section(72a) and a first projection member(72b).

Description: Background of The Invention The present invention relates to a vacuum cleaner, and more particularly to a vacuum cleaner which detects a quantity of dust using a dust sensor, which dust is included within an air sucked into a dust bag from a floor nozzle through a suction hose, which dust bag is housed within a vacuum cleaner body. From past, a vacuum cleaner having a dust sensor is presented. Such a vacuum cleaner has an arrangement such that a dust sensor is provided at a predetermined position of an air suction path which dust sensor operates optically, and a quantity of dust is detected using the dust sensor, which dust is included within an air which is sucked from a floor nozzle through a suction hose to a dust bag which is housed within a vacuum cleaner body. Therefore, a quantity of dust within a region which is to be cleaned is recognized based upon a quantity of dust which is detected using the dust sensor. And, it is judged whether or not cleaning is finished. A conventional dust sensor is classified into two groups. A dust sensor corresponding to one group detects a quantity of dust based upon an optical quantity of a light which passes across an air suction path. While, a dust sensor corresponding to the other group detects a quantity of dust based upon an optical quantity of a light which is reflected or scattered by dust particles within an air suction path. When the latter dust sensor is employed, a light is reflected or scattered by dust particles. An extent of a reflected or scattered light becomes a wider extent to some degree, while an extent of a received light by a light receiving device is a narrower extent to some degree. Therefore, a quantity of dust is detected based upon only a part (an extremely smaller quantity with respect to an entire reflected light and an entire scattered light) of a reflected or scattered light due to dust particles. Consequently, a dust detection sensitivity cannot be raised too much. On the contrary, when the former dust sensor is employed, a light is prevented from passing through the air suction path by dust particles. Therefore, most of radiated light from a light emitting device passed though the air suction path so as to reach the light receiving device. Consequently, a dust detection sensitivity can easily be raised. Therefore, the former dust sensor is employed when a dust sensor with high sensoitivity is required. An arrangement is most popularly employed as an arrangement of the former dust sensor that a light emitting device is provided at a predetermined position of a wall member of a pipe which constitutes an air suction path, and a light receiving device is provided at a predetermined position which opposes to the light radiating device. That is, an optical axis of the light emitting device and an optical axis of the light receiving device are coincident to one another. Further, a providing arrangement of the light emitting device and the light receiving device is most popularly employed, as is illustrated in Fig. 7, that a through hole is formed at a predetermined position of a wall member of a pipe which constitutes an air suction path, a case made of transparent resin is inserted and housed within the through hole, and the light emitting device or the light receiving device is inserted and housed within the case. When the providing arrangement is employed, a disadvantage arises in that providing condition of the light emitting device and the light receiving device vary depending upon a slight error in size, vibration given from outside of the dust sensor and the like so that the optical axis of the light emitting device and the optical axis of the light receiving device shift from one another. Further, a disadvantage arises in that the light emitting device and the light receiving device shift in a slipping out direction of the case, and/or the cases ahift in a slipping out direction of the wall member of the pipe so that a distance between the light emitting device and the light receiving device. Furthermore, a light radiated from the light emitting device is radiated within the pipe through a bottom wall of the case and the light radiated within the pipe is received by the light receiving device through a bottom wall of the case. Therefore, disadvantages arise in that a passing through quantity of a light is decreased, a light is scattered, a passing through direction of a light is shifted from the optical axes of the light emitting device and the light receiving device, when the bottom wall of the case has cracks, blur, and distortion which is formed during forming of the case. A predetermined dust detection sensitivity cannot be obtained even when any one of the above disadvantages arises. A vacuum cleaner according to the precharacterizing portion of claim 1 can be taken from EP 0 347 223 A. Summary of The Invention An object of the present invention is to coincide an optical axis of a light emitting device and an optical axis of a light receiving device with one another. Another object of the present invention is to maintain a distance between a light emitting device and a light receiving device to be a predetermined distance. A further object of the present invention is to guide a light from a light emitting device to a light receiving device efficiently. A vacuum cleaner according to the present invention includes a suction fan and a dust bag within a vacuum cleaner body, and guides dust with air to the dust bag through a suction path comprising a floor nozzle and a suction pipe, the vacuum cleaner comprises, a dust sensor having a light emitting device and a light receiving device, both devices being provided at predetermined positions of the suction path under a condition that both devices opposite to one another in a direction which is inclined by a predetermined angle with respect to a dust sucking direction, through holes for housing each of the light emitting device and the light receiving device, spacer members for housing each of the light emitting device and the light receiving device, the spacer members being housed within each through hole and is characterized by a large diametered flange provided at a base portion of each of the light emitting device and the light receiving device, a first concave section for housing the flange member, the first concave section being formed in the spacer member, a first projection member for preventing the flange from slipping out of the first concave section, the first projection member being provided at the spacer mamber, a second concave section provided at a predetermined position of an outer face of the spacer member, and a second projection member for engaging the second concave section so as to position the spacer member, the second projection member being formed on the wall forming the through hole. When the vacuum cleaner according to the present invention is employed, the spacer member is accurately positioned at a predetermined position of the suction path by an engagement of the second projection member and the second concave section. Each of the light emitting device and the light receiving member is accurately positioned at a predetermined position of the spacer member by an engagement of the first concave section and the first projection member. Therefore, each of the light emitting device and the light receiving device is accurately positioned to the suction path and is opposite to one another. And, the arrangement never shifts even when vibrations and the like are applied from outward so that a condition is continuously maintained that an optical axis of the light emitting device and an optical axis of the light receiving device are coincident to one another. Further, the light emitting device and the light receiving device are securely provided to the suction path even when the light emitting device, the light receiving device, the spacer member and the like have dimensional tolerance. Therefore, an assemble operator having no special skill can provide the light emitting device and the light receiving device in a condition that both optical axes of the light emitting device and the light receiving device are coincident to one another, without using a special tool. Furthermore, the spacer member made of arbitrary material can be employed so as to reduce the vacuum cleaner in its cost, because the spacer member affects no influence to a light propagation path between the light emitting device and the light receiving device. Brief Description of The Drawings Figure 1 is a diagram schematically illustrating a vacuum cleaner of an embodiment according to the present invention, Figure 2 is a cross sectional view illustrating a main portion of the vacuum cleaner, Figure 3 is a cross sectional view illustrating an arrangement of a portion in which a light emitting device is provided, Figure 4 is a cross sectional view illustrating a portion A of Fig. 2 in an enlarged manner, Figure 5 is a plan view illustrating the portion A of Fig. 2 in an enlarged manner, Figure 6 is a cross sectional view illustrating a portion B of Fig. 2 in an enlarged mariner, Figure 7 is a plane view illustrating the portion B of Fig. 2 in an enlarged manner, arid Figure 8 is a cross sectional view illustrating an arrangement of a portion of a conventional vacuum cleaner in which portion a light emitting device is provided. Detailed Description of The Preferred Embodiment Fig. 1 is a diagram schematically illustrating a vacuum cleaner of an embodiment according to the present invention. The vacuum cleaner comprises a vacuum cleaner body 1, a suction hose 2 which is provided to the vacuum cleaner body 1 in a removable manner, an extension pipe 3 which is provided to the suction hose 2 in a removable manner and a suction nozzle (floor nozzle) 4 which is provided to a leading edge section of the extension pipe 3 in a removable manner. The vacuum cleaner body 1 has a motor 11, a suction fan 12 which is rotated by the motor 11, a dust bag 13 for collecting dust which is included within a sucked air and an electrical circuitry section for controlling an operation of each section of the vacuum cleaner. The suction hose 2 has an operation section 5 for performing a remote operation at its leading edge section. The operation section 5 has a dust sensor 6 for detecting a quantity of sucked dust. The dust sensor 6 has a light emitting device 61 and a light receiving device 62, both devices 61 and 62 face to one another in a direction which crosses an air flowing direction flowing through the suction hose 2 by a right angle, as is illustrated in Fig. 2. Figs. 3 through 7 are diagrams illustrating a provision condition of the light emitting device. As is apparent from these figures, the light emitting device 61 is housed within a through hole 71 by interposing a spacer member 72 made of non-conductive material. The through hole 71 is formed at a predetermined position of a wall member of the suction hose 2. More particularly, the light emitting device 61 has a large diametered flange 61a at its base section and lead wires 61b for supplying an electric power for operation. The through hole 71 has a stepped section at its central section so that an inner side of the through hole with respect to the suction hose 2 is formed to have a smaller diameter and an outer side of the through hole with respect to the suction hose 2 is formed to have a large diameter. A second projection member 71a is formed at a predetermined position of a wall member corresponding to a large diametered section of the through hole 71. A number of the second projection members is at least one, and is three preferably. The spacer mamber 72 has an outer diameter which is nearly equal to the inner diameter of the large diametered section of the through hole 71. The spacer member 72 has a first concave section 72a for housing the flange 61a therein which first concave section 72a is formed at an inner side face of the spacer member 72 with respect to the suction hose 2. The spacer member 72 also has a first projection member 72b for pressing the flange 61a to a bottom face of the first concave section 72a which first projection member 72b is formed at a position corresponding to an opening edge section of the first concave section 72a. A number of the first projection members is at least one, and is three preferably. The spacer member 72 further has a second concave section 72c at a predetermined position of its outer face which second concave section 72c can be engaged with the second projection member 71a. The spacer mamber 72 has a central hole 72d for passing through the lead wires 61b of the light emitting device 61 which central hole 72d is communicated with the first concave section 72a. The position of the second projection member 71a and the position of the second concave section 72c are determined so that the spacer member 72 is positioned under a condition that the spacer member 72 is pressed to the stepped section of the through hole 71. Further, the second projection member 71a resiliently deforms when the spacer member 72 is inserted into the through hole 71. The second projection member 71a restores to the original state when the second projection member 71a engages the second concave section 72c so that the spacer member 72 is maintained in a condition that the spacer member 72 is prevented its slipping out from the through hole 71. The first projection member 72b resiliently deforms when the flange 61a is inserted into the first concave section 72a. The first projection member 72b restores to the original state when the flange 61a is housed its entirety within the first concave section 72a so that the flange 61a is maintained in a condition that the flange 61a is prevented its slipping out from the first concave section 72a. Furthermore, it is possible that a lens cover 72e made of transparent synthetic resin and the like is provided at the most inner side of the through hole with respect to the suction hose 2, as is illustrated with a dashed line in Fig. 2, so that dust is prevented from intruding in the through hole 71 by the lens cover 72e. A provision method of the lens cover may be similar to the provision method of the spacer member 72. Other various methods may be emploed as a provision method of the lens cover. Further, it is preferable that the lens cover is removable. A provision condition of the light receving device 62 is similar to that of the light emitting device 61, therefore description is omitted. Operation of the vacuum cleaner having the above arrangement is as follows. When the suction fan 12 is rotated by the motor 11, dust is sucked with air from the suction nozzle 4 through the extension pipe 3 and suction hose 2 so that only dust is collected by the dust bag 13. When a light radiated from the light emitting device 61 is received by the light receiving device 62, a quantity of received light becomes smaller responding to a case in which a quantity of sucked dust is great, while a quantity of received light becomes greater responding to a case in which a quantity of sucked dust is small. Therefore, a quantity of sucking dust is detected based upon a quantity of received light. That is, it is recognized whether or not cleaning has finished. Further, the light emitting device 61 and the light receiving device 62 are housed within the first concave section 72a of the spacer member 72 accurately in a slipping out preventing manner. The spacer member 72 is housed within the through hole 71 of the suction hose 2 accurately in a slipping out preventing manner. Therefore, an optical axis of the light emitting device 61 and an optical axis of the light receiving device 62 can be determined to be coincident to one another easily and accurately. Also, a distance between the light emitting device 61 and the light receiving device 62 is determined to be a predetermined distance easily and accurately. Furthermore, disadvantages are prevented from occurrence that the light emitting device 61 and the light receiving device 62 are shifted their positions and that the distance between the light emitting device 61 and the light receiving device 62 is varied, even when vibrations and the like are supplied from outside of the vacuum cleaner. Further, the second concave section 72c may be a concave section having a narrow width formed at a position which corresponds to the second projection member 71a. It is preferable that the second concave section 72c is a concave groove formed on an outer face of the spacer member 72. When the latter arrangement is employed, providing operation of the spacer member can be simplified.

Claims: A vacuum cleaner including a suction fan (12) and a dust bag (13) within a vacuum cleaner body (1), and guides dust with air to the dust bag (13) through a suction path comprising a floor nozzle (4) and a suction pipe (2), the vacuum cleaner comprising, a dust sensor (6) having a light emitting device (61) and a light receiving device (62), both devices (61, 62) being provided at predetermined positions of the suction path under a condition that both devices (61, 62) opposite to one another in a direction which is inclined by a predetermined angle with respect to a dust sucking direction, through holes (71) for housing each of the light emitting device (61) and the light receiving device (62), and spacer members (72) for housing each of the light emitting device (61) and the light receiving device (62), the spacer members (72) being housed within each through hole (71), characterized by : a large diametered flange (61a) provided at a base portion of each of the light emitting device (61) and the light receiving device (62), a first concave section (72a) for housing the flange member (61a), the first concave section (72a) being formed in the spacer member (72), a first projection member (72b) for preventing the flange member (61a) from slipping out of the first concave section (72a), the first projection member (72b) being provided at the spacer member (72), a second concave section (72c) provided at a predetermined position of an outer face of the spacer member (72), and a second projection member (71a) for engaging the second concave section (72c) so as to position the spacer member (72), the second projection member being formed on the wall forming the through hole. A vaccum cleaner as set forth in claim 1, wherein the through hole (71) includes a stepped section so that an inner diameter of an outer side of the through hole (71) with respect to the suction path is determined to be larger, while an inner diameter of an inner side of the through hole (71) with respect to the suction path is determined to be smaller. A vacuum cleaner as set forth in claim 1 or 2, wherein the spacer member (72) is housed within a larger diameter section of the through hole (71). A vacuum cleaner as set forth in one of claims 1 to 3, wherein the first projection member (72b) has resilience so as to permit force inserting of the flange member (61a) into the first concave section (72a), and the second projection member (71a) has resilience so as to permit forced inserting of the spacer member (72) into the through hole (71). A vacuum cleaner as set forth in one of claims 1 to 4, wherein the first projection member (72b) is formed at every distance by angle and the second projection member (72c) is formed at every distance by angle. A vacuum cleaner as set forth in one of claims 1 to 5, wherein the second concave section (72c) is a concave groove formed on an outer face of the spacer member (72).

Inventors: IMAMURA NOBUO, IMAMURA, NOBUO
Applicants: YASHIMA DENKI KK, YASHIMA ELECTRIC CO., LTD.
Application year: 1997
Main classification: A47L9
IPC codes: A47L9