GB2140288A - Suction cleaners - Google Patents

Abstract

A suction cleaner has an upright casing (14) provided with a door (20) on which filter bags (30) are mounted and a pivotable tube (42) having an outlet (50) provided with a seal (52) and a bag latching assembly (60), which automatically engages a collar (32) of a filter bag as the door is closed and transfers the filter bag from the door to the tube in sealing relationship therewith. When the door is closed and the cleaner used, dirt-laden air exhausts up tube 42 into the bag, inflation of the bag being accommodated by rearward pivotal movement of the tube 42. <IMAGE>

Description

SPECIFICATION Suction cleaners This invention relates to suction cleaners of the type which incorporate a disposable dirt bag usually made of porous paper. Many suction cleaners of this type have been manufactured, and proposed but not manufactured, in which the paper bags are manually inserted and removed from a cleaner casing. Generally speaking this involves awkward manual manipulation of the bag both during removal and insertion, and the user finds it difficult to keep his or her hands clean during this operation.

U.S. Specification 2646855 (Senne) proposes a filter replacement mechanism for a vacuum cleaner in which a filled bag is manually removed from a casing after the casing has automatically moved to an open position.

As the operator manually moves the casing back to its closed position the mechanisms therein will automatically release the lowermost of a reserve of fresh filter units and permit one of the units to drop in a swinging motion downward into a position occupied by the previously removed filter bag. This construction does not however provide for automatic securement of a filter bag in an operative position in relation to an air conduit.

German Specification 2139671 (Siemens) also discloses a construction in which a reserve of filter bags is shown but there is no reference as to how the bags are secured in position in the cleaner in their operative position.

According to one aspect of the present invention a suction cleaner has a bag carrier and a bag mount which are relatively movable towards one another to cause securing means automatically to secure a bag on the bag mount with an opening of the bag in sealing engagement with an air conduit, whereafter the bag carrier and the bag mount are relatively separable to permit the bag to expand between the bag carrier and the bag mount.

Conveniently, the bag carrier acts as a magazine to receive a plurality of bags. The bag carrier may be movable between an open position with respect to a casing to permit withdrawal of a full bag, and a bag-transfer position in which a bag on the carrier is addressed to the bag mount. The bag mount may be movable between a bag loading/bag unloading position and an operative region to which the bag is carried by the bag mount away from the bag carrier. The bag mount may be connected to the bag carrier so that movements of the bag mount are effected by moving the bag. carrier.However, there may be a catch to prevent movement of the bag mount by the bag carrier as far as the bag unloading position if the bag carrier is being moved merely to enable the user to see whether the bag requires changing, the catch being releasable by the user to permit movement of the bag mount to the bag unloading position if desired.

The securing means may comprise latches carried by the bag mount and adapted to engage spaced portions of a stiff bag collar provided on the bag. One such latch may be fixed relative to the bag mount while the other is movable relative to the bag mount and is biased to its latching position by a stationary guide which this latch engages during movement of the bag mount from the bag loading position, and with which the latch remains engaged while the bag mount is in the operative region. This latch may also be resiliently biased towards its latching position and be movable from its latching position to an unlatched position by movement of the bag mount from the operative region to the bag unloading position.

The bag mount preferably has a seal arranged to be compressed by movement of the bag collar when the bag carrier is moved to the bag-transfer position.

The cleaner may be of an upright type in which the bag mount comprises a tube extending upwards within an outer casing, the said air conduit being at the upper end of the tube and the tube being pivotally mounted about a horizontal axis at its lower end. The bag carrier may comprise a door to the outer casing which is pivoted to the remainder of the casing about an axis parallel to and in front of the said horizontal pivotal axis of the bag mount.

According to another aspect of the invention a suction cleaner has a bag mount which is arranged to receive a dirt bag in sealing relationship to an air conduit, the air conduit being movable between a bag loading position in which a bag may be addressed to the mount and a bag-latched position in which the bag is secured to the bag mount, and latching means carried by the air conduit and arranged automatically to secure the bag to the bag mount as the air conduit is moved between the bag loading position and the bag-latched position.

The invention also extends to a filter bag having characteristics hereinafter set forth rendering it suitable for use in a suction cleaner according to the invention, but salable as a separate article of commerce.

The invention may be carried into practice in a number of ways, and one specific embodiment will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an upright suction cleaner with a door in an open position and with certain parts broken away, Figure 2 is a perspective view of a paper bag with a cardboard collar secured thereto which is utilised in the cleaner of Figure 1, Figure 3 is a front view of the upper portion of the bag mount, Figure 4 is a plan view of a fixed portion of the suction cleaner, which co-operates with the upper portion of the bag mount, Figure 5 is a front view of the fixed portion shown in Figure 4, Figure 6 is a sectional side elevation of part of the cleaner, with its door closed and the bag mount in the operative region, Figure 7 is a sectional side elevation of the same part of the cleaner with the bag mount at the forward limit of the operative region, Figure 8 is a sectional side elevation of the same part showing the bag mount about to reach the bag unloading position, Figure 9 is a sectional side elevation of the same part in the bag unloading position in which the bag is ready to be removed by hand from the cleaner, and Figure 10 is a sectional side elevation of the same part with a new bag just engaged by the bag mount.

The embodiment of the invention shown in the drawings is applied to a fairly conventional upright cleaner having a lower casing 10 housing a motor fan unit which is arranged to drive an agitator situated at a forward suction nozzle 11. The lower casing 10 is mounted on a pair of forward wheels and a pair of rear wheels which are not visible in the drawings.

Extending upwards from the rear of the lower casing 10 is an upright, generally rectangular, casing 14 which is of a rigid nature and which is surmounted by a handle 16. The casing 14 is secured in its upright position of Figure 1 in a conventional manner by a latch, which can be released by a foot pedal not shown.

The casing 14 has a door 20 pivoted at its lower end about a horizontal axis on pivots 18. The door extends for the full height of the front of the casing 14 and is shown in an open position in Figure 1. The door also serves as a bag carrier. For this purpose it has two tongues 22 and 26 arranged in the same vertical plane, for mow ting a series of five paper bags of the type shown in Figure 2.

Each tongue has a hook-like enlargement 27 at its tip. Each bag comprises a folded and glued paper bag 30 made of conventional material which filters dirt from an air stream which passes through the porous wall of the bag. The bag has a stiff cardboard mounting collar 32 provided with an oblong opening 34 which is in register with a corresponding opening or mouth of the paper bag. One side of the collar projects beyond the side of the paper bag, and in this projecting side the collar has slots 36 and 40 to receive the door tongues 22 and 26, respectively. The vertical length of each slot is only slightly greater than the vertical height of the tongue behind the hook 27, and each slot is partly closed at its lower end by a hook-shaped portion 36A, 40A of the collar.Thus the collar is held against accidental dislodgement from the tongues, but the hook-shaped portions 36A, 40A have sufficient give to enable the slots to be passed over the tip hooks 27 of the tongues when the bags are being placed on the tongues, and when they are being automatically transferred from the tongues to their operative location, as described below. The door 20 acts as a magazine containing five bags with the cardboard collars 32 supported on the hooks 22, 26 and facing rearwards. The closing of the door from the position of Figure 1 automatically latches the rearmost bag collar onto the bag mount by means of a mechanism contained within the casing 14 in a manner to be described.

In addition to the two bag-supporting tongues 27, the door carries a locating prong 24 for a purpose. described later.

The casing 14 has extending upwardly therein an exhaust air fill tube 42 of a rigid tubular nature connected at its lower end by a bellows, not shown, to an exhaust opening extending from the outlet of the motor fan unit. At the back of the fill tube 42 near the bottom is a downwardly facing lip 12 which rests on a ledge 13 in the casing 14 to form a pivot having a horizontal axis. This pivotal axis is to the rear of the axis of the pivots 18 of the door 20 so that points on the fill tube 42 and on the door 20 which are equidistant from the respective pivot axes move along different axes. Somewhat above the level of the pivots 18, the door 20 is connected to one side of the fill tube 42 by means of a strap 46.The rear portion of the strap 46 is integral with the fill tube, the whole strap and the fill tube being parts of a one-piece moulding of a suitable plastics material such as polypropylene. The front end portion of the strap is secured to the door 20 at 19, e.g. by a screw. Spaced apart along the length of the strap between the end portions are three living hinges, i.e. transverse strips of reduced thickness, defining two intermediate hinged portions, 46A and 46B.

The fill tube 42 constitutes a bag mount. It extends upwards within the casing 14 and terminates in a forwardly facing outlet 50 which is surrounded by a seal 52 formed of foam plastics. Upstanding from the top forward edge of the opening 50 in front of the upper portion of the seal 52 is a hook 54.

The hook 54 is not secured to the seal 52 so that, as will be described, the cardboard collar 32 of a bag can be addressed up against the seal 52 and the seal 52 compressed to the position shown in Figure 10, at which time the collar 32 of the bag lies in a plane slightly behind the hook 54. The bag and collar achieve this position during the closing movement of the door to the position of Figure 6.

Moulded integrally with the rear upper end of the fill tube 42 are bag securing means.

These means comprise a movable bag latch ing assembly generally indicated at 60, which includes lateral lugs 62 to which are con nected, via living hinges 64, an upper latch member 66 which includes a generally hori zontal portion 66A projecting from a rear wall 65, and a downwardly turned latch 66B, together with a rear tab 66C upstanding from the rear wall 65. The member 66 also com prises a pair of vertical webs 66D and 66E shown most clearly in Figure 3.

The upper latch member 66 also includes, at each side of the member 66 and bridging the hinge 64, a roughly C-shaped integral spring portion 67. The lower limb of the C is connected to the corresponding lateral lug 62 by a lower living hinge 56, and the upper limb of the C is connected to a rear wall 65 by an upper living hinge 58. When the rear wall 65 is in alignment with the lateral lugs 62, as shown in Figures 6, 7, 8 and 10, the spring portion 67 is virtually unstressed.

When, however, the rear wall 65 is forced into an inclined position relative to the lateral lugs 62, accompanied by flexure at the living hinges 64, as shown in Figures 1 and 9, the locus of movement of the upper living hinge 58 is along an arc struck about the living hinge 64, so the distance between the upper and lower living hinges 56 and 58 is reduced and each C-shaped spring portion 67 is distorted. The reaction to this strain on the spring portions 67 is to apply a restoring force tending to urge the rear wall 65 back into alignment with the lateral lugs 62.

Each of the vertical webs 66D and 66E has an upwardly facing arcuate surface 61 D and 61 E, and an inwardly facing vertical surface 63D and 63E, respectively. The arcuate surfaces 61 D and 61 E are struck about the horizontal pivotal axis of the fill tube 42, defined by the axis of engagement of the lip 12 with the ledge 13. In most positions of the fill tube, as shown in Figures 6, 7, 8 and 10, the arcuate surfaces are close to, or touching, corresponding arcuate surfaces on the bottom edges of parallel guides 86 and 88 extending downwards from an upper interior part of the casing 14. These guides are also seen in Figures 4 and 5. The inwardly facing vertical surfaces 63D and 63E are close to, or touch the outer vertical surfaces of the guides 86 and 88, respectively, when the fill tube is in the positions of Figures 6, 7, 8 and 10.These guides thus aid in guiding the fill tube during its backward and forward pivotal movements.

The bag securing means also comprise, in addition to the movable bag latching assembly 60, a lower latch 80 which is integral with, and immovable relatively to, the fill tube 42.

Beside the lower latch 80, and also integral with the fill tube 42, there is a laterally extending rib 23 (see Figure 3) and an adjacent inverted L section formation 25. These are spaced apart to define a forwardly-facing inverted L section passage to receive the locat ing prong 24 on the door 20 when the latter is approaching its closed position, to ensure proper alignment of the fill tube 42 in relation to the door 20 carrying the bags 30. in the bag-transfer position.

The upper end of the upstanding tab 66C of the movable latching assembly is approxi mately T shaped when viewed from the front, as in Figure 3, the cross-piece of the T being just narrow enough to pass freely between the guides 86 and 88. At its forward end, each guide 86 and 88 has on its lower inner edge an inwardly facing ledge, 70 and 71, respectively. These ledges have inclined lead-in surfaces 70A and 71A, respectively. These serve to centralise the upstanding tab 66C as it approaches the forward end of the guides, e.g. as shown in Figure 8. The guide 86 also has. above the ledge 70, a wedge-shaped detent 72. Between the guides 86 and 88 there is a forwardly projecting spring latch 69 having at its forward end a downwardly facing nctch 68. Above the notch 68 the latch has a rearwardly facing vertical surface 73.In the centre of the crosspiece of the upstanding tab 66C there is a lowered surface 74 adapted to be received in the notch 68 of the spring latch 69. On each side of the lowered surface 74 the ends of the crosspiece of the tab 66C extend rearwardly as lugs 75.

Outside of the guide 86 there is a spring latch 76 which normally occupies the lower position shown in Figures 5, 6. 7 and 9, where it would obstruct forward movement of the fill tube 42 beyond the position shown in Figure 7, the bottom of the latch 76 in this position lying across the path of a lateral lug 77 on the vertical web 66D of the movable latching assembly 60.

The automatic bag changing mechanism works as follows: Assume that a bag 30 is already latched to the bag mount at the upper end of the fill tube 42, as shown in Figure 6. The bag collar 32 is held with its bottom edge behind the fixed lower latch 80 and with its top edge behind the movable upper latch 66B, compressing the seal 52 and making a substantially airtight joint between the bag opening 34 and the fill tube outlet 50. Dirty air sucked into the cleaner through the suction nozzle 11 by the fan is blow up through the fill tube 42 and into the bag 30, where the dirt is filtered out, the clean air emerging through the bag walls and being returned to the room through apertures in the casing 14.The fill tube 42 can pivot freely back and forth throughout its operative region, between a rearmost position limited by the back wall of the casing 14, and a foremost position as show in Figure 7 where the lateral lug 77 on the vertical web 66D (Figure 3) has come up against the bottom of the manually operable spring latch 76 (Figure 5). This freedom of movement in the operative region permits the fill tube 42 to position itself to accommodate variations in the size of the bag 30 as it becomes increasingly full.

If the user wishes to inspect the bag, e.g. to see whether it is full enough to need changing, she can open the door 20. This draws the fill tube 42 and the bag 30 to the foremost limit of the operative region as shown in Figure 7. The spring latch 76 prevents the fill tube and bag from moving beyond the Figure 7 position. If the bag does not require changing, the user closes the door and the parts revert to the Figure 6 condition.

If the bag is full, the user raises the spring latch 76 and opens the door further, to allow the lateral lug 77 to pass beneath the latch 76. The latch is then released and springs down behind the lateral lug, allowing the fill tube 42 to be draw further forward as show in Figure 8. During this movement the upstanding tab 66C passes between the ledges 70, 71 of the guides 86 and 88 (Figures 4 and 5), ensuring that the tab 66C and hence the bag mount as a whole, are properly centered laterally. In the Figure 8 position, the top of the tab 66C has made contact with the vertical surface 73 of the spring latch 69. The lug 75 on the side of the tab 66C nearest the guide 86 has passed above the wedgeshaped detent 72 on this guide. The bag collar 32 is still held between the lower fixed latch 80 and the upper movable latch 66B.

On opening the door further, the fill tube 42 continues to be drawn forward from the Figure 8 position, but the top of the tab 66C cannot partake of this movement, being restrained by the vertical surface 73 of the spring latch 69. This further movement therefore causes the upper portions of the bag latch assembly 60, namely all the portions above the living hinges 64, to be tilted upwards relative to the portions below the hinges 64, as shown in Figure 9. This raises the movable upper latch 66B well clear of the bag collar 32, allowing the seal 52 to expand and allowing the bag to be lifted clear of the fixed lower latch 80 and removed from the cleaner. This tilting movement of the upper portions of the latch assembly causes the tab 66C to slide dow the vertical surface 73 until the lowered surface 74 of the tab enters the notch 68 of the spring latch 69.Also. the lug 77 of the tab which passed over the detent 72 is brought dow to lie in front of the detent as shown.

For automatic replacement of the removed full bag by a new one from the magazine on the door, all the user has to do is to re-close the door. During the first part of the door reclosing movement the fill tube 42 is held against rearward movement because the lug 75 of the tab 66C is restrained against such rearward movement by the detent 72. What this part of the door re-closing movement does is to present the collar 32 of the rearmost bag in the magazine against the seal 52.

The arrangement is such that the upper edge of the opening in the collar 32 just clears the hook 54 of the bag mount, and the bottom edge of the collar just clears the fixed lower latch 80. Because the door 20 and the fill tube 42 pivot about different horizontal axes, they move on different axes. When the collar 32 has engaged the seal 52 the arc of movement of the fill tube and hence of the seal is rising relative to the arc of movement of the door. At first this causes the hook 54 and the latch 80 to rise relative to the collar 32 and so entrap the collar. This entrapment, and the friction between the collar and the seal, will then cause the collar to follow the arc of movement of the fill tube 42 rather than that of the door. This has the effect of lifting the collar relatively to the door, particularly relative to the door tongues 22 and 26.This lifting movement is permitted by the partially open lower ends of the slots 36 and 40 in the collar, allowing the collar to be lifted over the hook-like tips 27 of the tongues while the bags still left in the magazine remain held by the tongues.

A stronger closing force is then needed to close the door further. The effect of this is to straighten out the bag latching assembly about the hinges 64. This forces the tab 66C upwards, pressing it up against the spring latch 69. This latch is forced upwards, as show in Figure 10, as the latching assembly is straightened. The straightening causes the upper parts of the assembly, above the hinges 64, to tilt downwards relative to the parts below the hinges 64 so that the upper latch 66B engages the top edge of the bag collar 32. The lugs 75 of the tab 66C are raised clear of the detent 72 which no longer resists rearward movement of the tab 66C. However, it is still restrained by its lowered surface 74 being engaged in the notch 68 of the spring latch 69.

A further push on the door 20 will force the lowered surface 74 of the tab 66C out of the notch 68, allowing the bag mount, to which the new bag is now latched in place, to move back into the operative region shown in Figures 6 and 7. As can be seen in Figure 5, the righthand front lower corner 81 of the manually operable latch 76 is chamfered to form a lead-in which is engaged by the lateral lug 77 of the vertical web 66D as the bag mount is moved rearwards, so that the lug 77 itself lifts the latch 76 and passes beneath it.

Thus the user of the cleaner only has periodically to load a magazine of bags into the door and close the door of the cleaner in order to install the first bag in the cleaner.

When requiring changing, the bags are removed in the manner indicated and the fresh bags installed simply by re-closing the door.

The operator has no intricate assembly work to carry out and can keep his or her hands perfectly clean during the replacement opera tion. If in checking a bag after removal, the user finds that in fact it need not be replaced yet, the bag can be simply reinserted manu ally by direct engagement with the latching means rather than placing back on the ton gues on the door.

Claims (4)

1. A suction cleaner having a bag carrier and a bag mount which are relatively movable towards one another to cause securing means automatically to secure a bag on the bag mount with an opening of the bag in sealing engagement with an air conduit, whereafter the bag carrier and the bag mount are relatively separable to permit the bag to expand between the bag carrier and the bag mount:

2. A suction cleaner as claimed in Claim 1 in which the bag carrier acts as a magazine to receive a plurality of bags.

3. A suction cleaner as claimed in Claim 1 or Claim 2 in which the bag carrier is movable between an open position with respect to a casing to permit withdrawal of a full bag and a bag-transfer position in which a bag on the carrier is addressed to the bag mount.

4. A suction cleaner filter bag substantially as described herein with reference to Fig. 2 of the accompany drawings.

4. A suction cleaner as claimed in any of the preceding claims in which the bag has a stiff collar surrow ding the bag opening,

5. A suction cleaner as claimed in Claim 4 in which the bag carrier has at least one bag mounting tongue and the bag collar has at least one edge portion extending beyond an edge of the bag, with at least one slot in the edge portion or portions disposed to receive a bag mounting tongue and to be removably retained on the bag carrier by that tongue.

6. A suction cleaner as claimed in Claim 5 in which at least one bag mounting tongue has a shank which can be received in a slot in the bag collar and an enlarged tip to prevent the collar from sliding freely off the tongue.

7. A suction cleaner as claimed in Claim 6 in which one end of the slot is closed and the other end has a restricted opening to permit the bag collar to be placed on the tongue and removed therefrom past the enlarged tip with distortion of the collar adjacent the restricted opening of the slot.

8. A suction cleaner as claimed in any of Claims 5 to 7 in which there are two spaced bag mounting tongues lying substantially in the same vertical plane on the bag carrier, and two corresponding spaced slots in one edge portion of the bag collar.

9. A suction cleaner as claimed in any of Claims 4 to 8 in which the bag mount has a seal arranged to be compressed by movement of the bag collar when the bag carrier is moved to the bag-transfer position.

10. A suction cleaner as claimed in any of the preceding claims in which the bag mount is movable between a bag loading/bag un loading position and an operative region to which the bag is carried by the bag mount away from the bag carrier.

11. A suction cleaner as claimed in Claim 10 in which the bag mount is movable from its operative region to the bag unloading position by movement of the bag carrier.

12. A suction cleaner as claimed in Claim 10 or Claim 11 having a catch to prevent movement of the bag mou t from its operative region to the bag unloading position, the catch being releasable to permit such movement.

1 3. A suction cleaner as claimed in any of Claims 4 to 9, and in any of Claims 9 to 12, in which the securing means comprise latches carried by the bag mount and adapted to engage spaced portions of the bag collar, one latch being fixed relative to the bag mount and another latch being movable relative to the bag mount and biased to a latching position.

14. A suction cleaner as claimed in Claim 13 in which the said other latch is biased to its latching position by a stationary guide which this latch engages on movement of the bag mount from the bag loading position.

15. A suction cleaner as claimed in Claim 13 or Claim 14 in which the said other latch is resiliently biased towards its latching position and is moved from its latching position to an unlatched position by movement of the bag mount from its operative region to the bag unloading position.

16. A suction cleaner as claimed in any of Claims 13 to 15 having resilient detent means to hold the said other latch in an u latched position when the bag mount has been moved into the bag loading/bag unloading position and thereby to hold the bag mount in that position.

17. A suction cleaner as claimed in Claim 3 and in Claim 16 in which the said other latch is releasable from the resilient detent by forcing the bag carrier through the bag transfer position.

18. A suction cleaner as claimed in any one of the preceding claims which is of an upright type and in which the bag mount comprises a tube extending upwards within an outer casing, said air conduit being at the upper end of the tube and the tube being pivotally mounted about a horizontal axis.

19. A suction cleaner as claimed in Claim 18 in which the bag carrier comprises a door to the outer casing which is pivoted to the remainder of the casing about an axis parallel to and in front of said horizontal axis.

20. A suction cleaner having a bag mount which is arranged to receive a dirt bag in sealing relationship to an air conduit, the air conduit being movable between a bag loading position in which a bag may be addressed to the mount and a bag-latched position in which the bag is secured to the bag mount, and latching means carried by the air conduit and arranged automatically to secure the bag to the bag mount as the air conduit is moved between the bag loading position and the bag-latched position.

21. A suction cleaner substantially as described herein with reference to the accompanying drawings.

22. A suction cleaner filter bag comprising a porous paper bag having an opening, a stiff bag collar secured to the exterior of the paper bag around the bag opening, at least one edge portion of the collar extending beyond an edge of the paper bag, the collar having at least one elongate slot in said edge portion or portions to receive a mounting tongue on a suction cleaner.

23. A suction cleaner filter bag as claimed in Claim 22 in which one end of the slot is closed and the other end has a restricted opening.

24. A suction cleaner filter bag as claimed in Claim 22 or Claim 23 in which there are at least two longitudinally aligned elongate slots in one said edge portion of the collar.

25. A suction cleaner filter bag substantially as described herein with reference to the accompanying drawings.