Patent GB-681911-A (GB)
Title: Improvements in and relating to dishwashing apparatus
IPC: A47L15/06
Filed: 1949-10-27
Abstract: 681,911. Dishwashing machines. BRITISH THOMSON-HOUSTON CO., Ltd. Oct. 27, 1949 [Oct. 30, 1948], No. 27575/49. Class 138 (i). [Also in Group XXV] Relates to a dishwashing machine comprising a vat having a front opening gasketless door, in which the bottom flange of the vat doorway is provided with an upwardly directed ledge extending between the side flanges of the doorway, wherein hinge mechanism co-operating between the said bottom flange and the lower portion of the door is arranged within the doorway rearwardly of the said ledge. The dishwashing apparatus, Figs. 2 and 3, includes a vat 23 having a front doorway 29 closable by a door 48 without the need of a sealing gasket between the doorway and the door, and a dish receptacle 111 which is provided with rollers to enable it to be slid over tracks on the door in its horizontal open position into the vat for support therein on guides provided in the side walls of the vat. The apparatus automatically performs a predetermined sequence of operations including the steps of spraying, washing including the adding of a detergent, rinsing and drying of the dishes and other utensils in the manner described in the copending Specification 663,586. The doorway 29 comprises a top flange 31, side flanges 32, 33 and a bottom flange 34 terminating in an upwardly and outwardly extending ledge 35 which extends between the side flanges 32, 33. At the junction of the vat 23 and doorway 29 the vat is provided with an inverted substantially U- shaped inwardly embossed rib 38 having a top portion 39 formed in the top wall 24 of the vat and side portions 40, 41 formed in side walls 26, 27, of the vat. The side wall 26 is formed with inwardly embossed baffles 42, 43, parallel to the emboss 40 and a substantially horizontal inwardly embossed guide member 46 at the lower ends of the baffles 42,43. The side wall 27 is formed with inwardly embossed baffles 44, 45 parallel to the emboss 41 and a substantially horizontal inwardly embossed guide member 47 at the lower ends of the baffles 44, 45. The guide members 46, 47 are substantially parallel and decline slightly towards the rear wall 28 of the vat. The door 48, Figs. 5 and 7, comprises an outer body sheet 49, provided with a U-shaped marginal flange including a top portion 50 and side portions 51, 62, and an inner body sheet 53 provided with a U-shaped marginal flange, including a top portion 54 and side portions 55, 56. The inner sheet 53 is arranged in nested relation with the outer sheet 49 and suitably secured in place in spaced relation to the outer sheet, a bracing sheet 58 being provided. The marginal flange of the sheet 49 is provided with a rim having a top portion 62 and side portions 63, 64. Attached to the inner side of the marginal flange of the sheet 53 is a U- shaped baffle provided with a top portion 77 and side portions 78, 79. A portion 77a of the baffle portion 77 extends under the top flange portion 54 of the sheet 53 and serves to cover vent holes 54a formed in the portion 54. The door is pivotally mounted within the doorway 29 by two identical hinge mechanisms disposed behind the ledge 35 at each side of the doorway. The hinge mechanism 66, Figs. 5 and 7, comprises a hori-. zontal pintle member 73 carried by an element 71 secured to the flange 34 which co-operates with a U-shaped open-ended saddle member 74 carried by a member 72 secured to the inner sheet 53. The door can thus pivot between the substantially vertical position in which it closes the doorway 29 and a substantially open position in which it is supported by the ledge 35. In positions intermediate of the closed and open positions the arrangement of the hinge mechanisms allows of the door being completely removed from the doorway as shown in Fig. 7. The upper side of the inner sheet 53, Fig. 5, is provided with a centrally disposed trackway 91 and two L-shaped upstanding embossed strengthening ribs 84, 85, the stems 86, 88 of which carry side trackways 96, 97. The trackways 96, 97 comprise respectively oppositely sloping surfaces 100, 102, and 101, 103 respectively. The sheet 53 is also provided with a tail 90, which cooperates with a groove 37 formed in the bottom flange 34, and a recess 92 in which a detergent cup 93 is arranged and secured in place between the sheets 53 and 49. The cup 93 is surrounded by a flange 94 spaced above the sheet 53. The flange 94 is so arranged to prevent entry of washing liquid into the cup 93 during a spraying operation and thereby serves a similar purpose to the deflecting ribs formed on the door and around the detergent cup disclosed in the copending Specification 663,586. The dish receptacle 110, Fig. 9, is formed by the lower receptacle 111, Fig. 2, and two upper baskets (not shown) which are mounted on the lower receptacle. The receptacle 111 is provided with rollers 122, engageable with the guide members 46, 47 in the vat 23; rollers 125, engageable with the trackways 96, 97, on the door 48; feet 123', Fig. 4, engageable with the guide members 46, 47; and a roller 124 engageable with the trackway 91 on the door 48, and a vertical baffle 113, Fig. 3, which co-operates with the baffle 78. In the position shown in Fig. 9 the receptacle 110 is supported in the vat by the rollers 122 and the feet 123 engaging the guide members 46, 47, and the door is in its closed vertical position being retained by a latch mechanism comprising a spring member 81 engageable by a member 80, Figs. 2 and 7. The opening of the door 48 to its horizontal position causes the tail 90 to lift the roller 124 and thus disengage the feet 123 from the guide members 46, 47. The receptacle 110 may now be slid out from the vat, the roller 124 engaging in the trackway 91. Before the rollers 122 disengage the guide members 46, 47 the rollers 125 engage with the portions 100, 101 of the trackways 96, 97 and as the rollers move up the sloping track portions the rollers 122 disengage the guide members 46, 47. The rollers 125 then engage the downwardly sloping portions 102, 103 of the trackways 96, 97 and the roller 124 moves into a depression 95, Fig. 2, formed in the inner sheet 53 of the door, and the receptacle is then retained in its retracted position, lateral movement being restrained by the marginal flanges on the door. When the receptacle is slid into the vat the above operations are carried out in a reverse sequence. When the receptacle is supported in the vat and the door is closed, an electric switch 82, Fig. 2, is operated by a member 83 carried by the door and this switch prepares the electrical circuit of the apparatus which is then operated by a push button (not shown) so that the timed operations of spraying, washing, rinsing and drying are carried out. In the closed position of the door, Fig. 3, the baffles 78, 79 co-operate in non-scraping relationship with baffles 42, 44 and ribs 40, 41, and the baffle 77 co-operates with the rib 39. The marginal flange 50, 51, 52 of the outer door sheet 49 cooperates in non-scraping relationship with the flanges 31, 32, 33 of the doorway 29, while the marginal rim 62, 63, 64 of the marginal flange of the sheet 49 engages with the ribs 39, 40 and 41. All the above mentioned co-operating baffles together with the vat baffles 43, 45 and the dish receptacle baffle 113 ensure that washing liquid thrown up by the impeller 130 is prevented from emerging through the doorway and past the door. The vat is vented to the exterior even when the door is closed by the openings 54a formed in the marginal flange 54 and expelled liquid is baffled therefrom by the portion 77a of the baffle 77. The door latch member 80, trackways 96, 97, and the impeller 130, may be formed of resin-bonded textile material.