Vacuum cleaners

Abstract: An electric vacuum cleaner having a body (1), suction generating means (7) and a dust collection space in said body, and a rotatable hose inlet (30) for receiving a suction hose (66) and connecting the hose to the dust collection space. The suction hose has at one end a coupling (67) engageable with said hose inlet. An electrical power supply cord socket (109) is arranged to receive a plug of a power supply cord (112) for a powered accessory (108) of the vacuum cleaner. To avoid twisting of the cord around the hose, the cord socket (109) is located on the hose coupling (67).

Description: BACKGROUND OF THE INVENTION 1. Field of the invention This invention relates to vacuum cleaners, particularly electric vacuum cleaners. 2. Description of the prior art Electric vacuum cleaners have been highly developed in recent years, and many different models have been placed on the market. Vacuum cleaners for use in the home are generally of two types, often known as the cylinder type and the upright type. The cylinder type has a body, usually mounted on wheels, and containing an electric motor driving suction generating means such as a fan and a dust collection chamber in which usually dust collection bags are mounted to filter the sucked air. The air is sucked through a hose from a cleaning accessory such as a brush or a nozzle at the remote end of the hose. The hose has a coupling detachably connectable to a hose inlet leading to the dust collection chamber. Cleaning is conducted by moving the accessory over the surface to be cleaned. The upright type differs in that the surface to be cleaned is located immediately beneath the body, so that a hose and an accessory are not required. Nevertheless the upright type is usually adaptable so as alternatively to suck air through a hose from a remote accessory. The upright type has the advantage that the body may also carry one or more brushes which are driven in rotation, and which contact the surface to be cleaned which is particularly advantageous when cleaning carpets. Recently, in order to provide the same advantage in a cylinder type vacuum cleaner, there has been provided an accessory for mounting at the end of the hose, which itself has one or more rotating brushes for contacting the surface being cleaned. An electric motor mounted in the accessory rotates the brush or brushes. To supply electric power to this accessory, a cord or lead may be arranged inside the hose. The hose coupling engageable with the hose inlet and the hose inlet itself have a plug and socket arrangement for connecting this lead to electrical power source in the vacuum cleaner body. Safety requirements in some countries may not permit this arrangement. In that case, the electrical supply cord for the powered accessory must be located outside the hose, and a socket is provided on the vacuum cleaner body for insertion of a plug at one end of the cord. An example of the latter arrangement is shown in JP-A-58-49128, in which the power supply socket is arranged in the upper surface of the vacuum cleaner body. US-A-4550958 shows a power supply socket located on a rotateable hose inlet of the body. This power supply cord to the accessory is conveniently attached by clips to the hose, so that it does not trail and become entangled with the vacuum cleaner or furniture etc. However, in order to allow flexing or rotation of the hose portion near the body, there must still be a free portion of cord which can form a loop which is liable to catch on the user or on furniture. If the hose is rotatable relative to the body, the cord becomes twisted around the hose. It is an object of the present invention, in a first aspect, to solve this first problem. SUMMARY OF THE INVENTION The present invention provides an electric vacuum cleaner having suction generating means and a dust collection space in a body and a hose inlet for receiving a suction hose and connecting the hose to the dust collection space. The suction hose has at one end a coupling engageable with said hose inlet, and an electrical power supply cord socket on the coupling to receive a plug of a power supply cord for an accessory of the electric vacuum cleaner. Especially when the coupling of the hose is rotatable relative to the body when received in the hose inlet, this location of the cord socket prevents entanglement of the cord with the hose. It is preferred that the suction air flow path through the hose has a bend at the coupling, and the cord socket on the coupling is located at the inside of said bend. BRIEF INTRODUCTION OF THE DRAWINGS An embodiment of the invention will now be described by way of non-limitative example with reference to the accompanying drawings, in which:- Fig. 1 is a general vertical sectional view, at a central longitudinal plane, of an electric vacuum cleaner of the cylinder type embodying this invention; Fig. 2 is a perspective view of the vacuum cleaner of Fig. 1 with a suction hose and accessory attached to it; 1 ; Fig. 3 is an exploded perspective view of parts providing the hose inlet of the vacuum cleaner of Fig. 1; Fig. 4 is a top plan view of an inner cover member shown in Fig. 3; Fig. 5 is a top plan view of a socket part of the hose inlet of Fig. 3; Fig. 6 is a vertical sectional view on the line 14-14 of Fig. 5; Fig. 7a is a top plan view of a connector part of the hose inlet of Fig. 3; Fig. 7b is a diametrical sectional view of the connector part of Fig. 1; Fig. 8 is an exploded view of the hose of the vacuum cleaner of Fig. 1; Fig. 9 is a rear view, partly in section, of the hose coupling of the hose of Fig. 8; Fig. 10 is an axial section of the hose coupling of Fig. 9; Fig. 11 is a side view, partly in section, of the hose coupling of Fig. 9; DESCRIPTION OF THE PREFERRED EMBODIMENT In the following description, not all parts illustrated will be fully described, since many parts embody conventional technology and are not directly relevant to the inventive concepts which form the subject of this specification. The construction of such parts will not cause difficulty to the expert designer of vacuum cleaners. As is conventional, many of the parts of the vacuum cleaner are plastics mouldings. The vacuum cleaner shown in Fig. 1 has a structural body 1 mounted on a front caster wheel 10 and two rear wheels 11 on fixed axes and comprising a lower casing 2 and a top casing 4 rigidly attached thereto. Pivotally mounted on the top casing 4 is a dust chamber cover 3 which carries a hose inlet 30. At the front of the body 1 there is a handle 5. A shock-absorbing furniture guard 6 extends around the front and sides of the body 1 at the level of the handle 5. The body 1 encloses an electric blower 7 including an electric motor, a cord reel (not shown) for the winding up of a cord for supply of electric power to the vacuum cleaner from the mains and a dust collection bag 9 shown occupying a dust collection chamber. The cover 3 in its closed position closes the top of the dust collection chamber, and is pivotably openable to allow insertion and removal of the bag 9. At the front of the body 1, there is mounted a holder 12 for storing a hose extension tube. Close to the rear is a rack 13 for storing several small cleaning accessories, closed by a cover 14. The accessories received in this rack 13 are, for example, a crevice nozzle 15. At the rear is an air exhaust port 19. The suction air being exhausted passes to the port 19 through a filter 20 carried in a removable filter casing 21. To seal the filter casing 21 to the top casing 4, the filter casing 21 has a seal mounting recess 22 extending around its periphery. The seal is not shown. On the top of the top casing 4 there is mounted a box 25 covering a printed circuit board 24 and having a top panel 135 through which switch operating buttons 136 project. Laterally of this box 25 (see Fig. 2), there are respectively a pivotable pedal switch 26 for turning on and off the power supply to the electric blower 7 and a pivotable pedal 27 for controlling the operation of the cord reel. Fig. 2 also shows a flexible suction hose 66 of conventional corrugated wall type having at its end remote from the cleaner body 1 a rigid extension tube 69 carrying at its remote end an accessory 108 which here is a powered accessory requiring a supply of electric power to it via the vacuum cleaner body 1. This powered accessory 108 is for example one including an electric motor driving a brush in rotation, particularly for use in cleaning carpets. At its other end, the hose 66 has a hose coupling 67 which is received by the hose inlet 30. The coupling 67 and the inlet 30 are described in more detail below. Fig. 2 shows that the coupling 67 which is rotatable relative to the body 1, as also described below, has on it an electrical power socket 109 which receives a plug 110 at one end of an electrical power supply cord 112. The other end of the cord 112 has a socket which engages with a plug member on the accessory 108. The electrical supply cord 112 is typically a two-wire cord of a suitable type for the voltage and power required by the accessory 108. The cord 112 is clipped to the hose 66 and the extension tube 69 by clips 111. It can be seen from Fig. 2 and more clearly from Figs. 8 to 11 that the suction air passage through the coupling 67 has a bend in it. The socket 109 is located at the inside of this bend, i.e. at the concave side of this bend. This location protects the socket 109 due to the shape of the coupling 67. The socket 109 does not interfere with the handling of the coupling 67 when attaching it to or detaching it from the body 1. Figs. 3 to 8 show the hose inlet 30 which is mounted on the cover 3. Fig. 1 shows that the cover 3 has an inner cover 76 with an aperture 76b secured to its inner face and enclosing and supporting the hose inlet 30. A seal 35 seals between the inner cover 76 and the cover 3. Fixed on the inner cover 76 is a support plate 62 having a central aperture. Surrounding the central aperture is a bearing 62b for the rotatable parts of the inlet 30 which are (i) a hose receiving socket member 31 mounted on one side of the plate 62, (ii) an electrical connection member 61 secured to the socket member 31 and located on the other side of the plate 62 from the socket member 31 and (iii) a rubber seal 34 which is held in the central aperture of the connection member 61 and seals against the periphery of the aperture 76b in the inner cover 76. The seal 34 has a central passage which is closed by triangular flexible rubber flaps 34a which are moved aside when the hose coupling 67 is inserted. The aperture 76b in the inner cover 76 is bounded by wall which projects into the dust bag 9, when the cover 3 is closed. A rubber seal 73 mounted on the inside face of the inner cover 76 assists in the sealing of the cover 3 to the bag 9. Fig. 4 shows that, adjacent to the aperture 76b, there are mounted two contacts 121 in the inner cover member 76. Each contact 121 consists of a pair of contact arms 121a terminating in contact surfaces 121b. These contacts 121 are connected to respective wires of the lead 120 mentioned above. The lead 120 is connected to a suitable power source in the vacuum cleaner body. It is mentioned now that Figs. 3 and 4 also show two bypass valves 71 which will be described further below. Figs. 8 to 11 show the coupling 67 at the end of the hose 66, which has a projecting nozzle 115. When the coupling 67 is received in the hose inlet 30, the nozzle 115 penetrates through the central aperture of the inlet 30 to the interior of the dust bag 9. Figs. 5 and 6 show the hose receiving socket member 31 which has a central aperture 31c. There are two rectangular recesses 31e on each side of the central aperture 31c which receive corresponding lugs on the coupling 67. Also on the coupling 67 are two electrical connection pins 124 which are received in correspondingly located stepped apertures 125. Figs. 7 and 8 show that the electrical connection member 61 has contacts 123 to engage the pins 124 when they are inserted through the apertures 125. The contacts 123 are connected to respective slip rings 122 which are in the form of continuous stamped metal rings having projecting lugs 122a which are bent round to hold the slip rings 122 in place. Both slip rings 122 face axially, and are located at levels corresponding to the positions of the fixed contacts 121 in the inner cover 76 described above, so that the contacts 121 engage the slip rings 122. The top openings of the apertures 125 in the member 31 are at the bases of recesses 31b in its top rim surface 31a, which are recessed by 3mm from the top surface 31a. The aperture 125 corresponds in shape to a protective insulating sleeve 127 surrounding the pin 124 on the hose coupling to provide appropriate insulation. The arrangement is such that the leading end of the sleeve 127 has entered the aperture 125, when the leading end of the pin 124 comes into contact with the contact 123. This prevents a user touching the pin 124 while it is electrically live. The recesses 31b also improve the strength of the moulded part. The recesses 31b also have four rib shaped projections 31d at the same height as the surface 31a at the rim of the socket member 31. This causes the connector 67 to be fitted into the socket member 31 in the correct position to prevent bending or breakage of the pins 124. As shown the connector 67 has two pins 124 and there are two corresponding contacts 123 in the electrical connection member 61. Fig. 13 shows that there are four apertures 125, which is to allow for additional electrical connections through the hose inlet 30 if desired. Likewise the connection member 61 has provision for addition of two additional slip rings facing radially outwardly on its peripheral surface and space for two additional contacts. The use of the slip rings 122 which extend 360° means that the hose coupling 67 is rotatable by more than 360 relative to the vacuum cleaner body 1. The number of rotations is unlimited. The cord 112 supplying electric power to the powered head 108 has, as already mentioned, a plug 110 at its end which is received in the socket 109 on the connector 67. The contacts in this socket 109 are connected by lead wires to the pins 124. As Fig. 8 shows, the socket 109 is mounted in a recessed position in the hose coupling 67 between two left and right cover members 116, 117 which also carry the rectangular lugs which mate with the recesses 31e in the socket member 31. Also located in the cover members 116, 117 is a latch member 118 which locks the connector 67 into the socket member 31 by engagement with a slot (not shown) provided in a wall of each of the recesses 31e, and is released by finger pressure on a button portion projecting from the cover member 117 (see Fig. 17). If the hose coupling 67 is to be sold without the socket 109, the socket 109 can be omitted, and the hole through which the plug 110 is inserted can be covered by a cover member. The adaptation can easily be made, and the Portion of the coupling 67 providing the space for the socket 109 does not protrude. The flexible tube 66 is detachably connected to the coupling 67 by a sealing ring 113 and a latching ring 114. The hose 66 can rotate in the coupling 67. By these arrangements a very high degree of freedom of movement of the hose 66 is achieved, with little risk of winding of the cord 112 around the hose, or of loose portions of the cord 112 becoming entangled with the user or with furniture. At its other end the hose 66 is connected by a seal ring 113 and a latching ring 114 to the rigid angle portion 68 which in turn is directly connectable to a cleaning accessory such as the powered head 108 or, as is conventional, extension tubes 69 may be employed.

Claims: An electric vacuum cleaner having a body (1) carrying a hose inlet (30) for receiving a detachable suction hose (66) and connecting said hose (66) to a dust collection space in said body (1) of the vacuum cleaner, said suction hose (66) including at one end a coupling (67) detachably engageable with said hose inlet (30), there being an electrical power supply cord socket (109) to receive a plug of a power supply cord (112) for an accessory (108) of said electric vacuum cleaner, characterised in that said cord socket (109) is located on said coupling (67) of said hose (66). An electric vacuum cleaner according to claim 1 wherein said coupling (67) of said hose (66) is rotatable relative to the vacuum cleaner body (1) when received in said hose inlet (30). An electric vacuum cleaner according to claim 2 wherein said coupling (67) is rotatable by more than 360° relative to said body (1), when received in said hose inlet (30). An electric vacuum cleaner according to claim 2 or claim 3 wherein said hose inlet (30) is rotatable in said body (1), when said hose (66) is received in it, so that said coupling (67) is rotatable relative to the body (1). An electric vacuum cleaner according to claim 4 wherein said hose inlet (30) and said coupling (67) have respectively socket (123) and plug (124) components of a plug and socket arrangement through which electrical power is provided to said cord socket (109) on said coupling (67). An electric vacuum cleaner according to claim 5 wherein said hose inlet (30) includes a plurality of slip rings (122) rotatable relative to said body (1) and contacts (121) engaging said slip rings (122) and fixed relative to said body (1), for transmission of electrical power to said plug and socket arrangement (123, 124). An electric vacuum cleaner according to claim 6 wherein said hose inlet (30) and said coupling (67) comprise a seal (34) to isolate said slip rings (122) and said plug and socket arrangement (123, 124) from suction air flow. An electric vacuum cleaner according to any one of claims 1 to 7 in combination with an accessory (108) connectable to the end of said hose (66) remote from said coupling (67) and including an electrically driven brush, electrical power for driving said brush being provided by a power supply cord (112) having a plug (110) receivable in said cord socket (109) on said coupling (67). An electric vacuum cleaner according to according to any one of claims 1 to 8 wherein a suction air flow path through said hose (66) has a bend at said coupling (67), said cord socket (109) being located at the inside of said bend. A suction hose (66) for an electric vacuum cleaner having a coupling (67) at one end for connection to a hose inlet (30) of said vacuum cleaner, characterised in that said coupling (67) has an electrical power supply cord socket (109) to receive a plug of an electrical power supply cord (112), and means (124) engageable with said hose inlet (30) for supply of electrical power to said cord socket (109).

Inventors: HIRUTA YASUYUKI, ISHII YOSHITARO, IWAO AKIRA, SUNAGAWA MASAO, SUZUKI NARUHIKO, HIRUTA, YASUYUKI, ISHII, YOSHITARO, IWAO, AKIRA, SUNAGAWA, MASAO, SUZUKI, NARUHIKO
Applicants: HITACHI LTD, HITACHI, LTD.
Application year: 1990
Main classification: A47L9
IPC codes: A47L9