Patent GB-552226-A (GB)
Title: Improvements in or relating to mechanism for use in paving
IPC: E01C19/18
Filed: 1941-08-22
Abstract: 552,226. Roads. BLAW KNOX, Ltd. Aug. 22, 1941, No. 10745. Convention date, Aug. 23. 1940. [Class 107] Relates to scraping or spreading means for use in road-building machinery supported on rails at each side of an area to be paved and provided with a runway on which a trolley, carrying a scraper, moves to and fro, and comprises cooperating means on the trolley and machine frame for turning the scraper about a vertical axis from one working position to another, and latch means controlled by movement of the trolley for holding the scraper in adjusted position during movement of the trolley to the opposite end of the runway. A frame 2, movable on wheels on forms A at each side of the surface to be paved, has a transverse runway comprising spaced channels 5, 6, on which runs a trolley' 7 supported by rollers 11, Fig. 5, within the channel 5 and rollers 12, 13, above and below the channel 6. The trolley has a sleeve 14 rotatably supporting a post 15 carrying a spreader 15<SP>1</SP> and also supporting a threaded sleeve 16 splined at 19 to the sleeve 14 and engaging the threaded hub 21 of a handwheel 20, whereby the spreader 151 may be raised and lowered, indicators 23 showing the position of the spreader. The trolley is reciprocated by a chain 25 continuously driven by a chain 33 through a shear pin 32, the chain 25 having a transverse pin 37 carrying rollers 37a, one roller 37a co-operating with a slotted guide 38 on the trolley and the other with upper and lower slotted guides 39, 40, thereon; fixed guides 26a, 27a, Fig. 1, guide the roller 37a between the guides 39, 40 during movement of the pin 37 round sprockets 26, 27, of which sprocket 27 is adjustable. The spreader is preferably normally inclined as shown so as to advance the paving material besides moving it laterally, and towards each end of the movement of the trolley the spreader is turned to the other side of the heap of material through the engagement with stops 42a, 42b, of a roller 42 carried by an arm 41 splined to the post 15 ; in intermediate positions of the trolley, the scraper is held by engagement with the arm 41 of one of two pivoted latches 43, Figs. 1 and 3, stressed by springs 45, the acting latch being freed at the end of the movement of the trolley by the engagement with cam 46a or 46b of a roller 43d carried by the latch. Stops 47 on the trolley support the arm 41 at the limit of its rocking movement. A vertically adjustable screed engages the material after it has been spread. Specification 546,193 is referred to. The Specification as open to inspection under Sect. 91 describes a further form, in which two spreaders 56, 58, Fig. 13 (Cancelled), are connected by pivoted links 54, 60, carried by the trolley, and the guides for the pin 37 are carried by a crosshead 61 slidable within limits relatively to the trolley, whereby at each reversal of the trolley, movement of the crosshead acts through a guide 67 and a roller 69 on an arm 68 fixed to link 54 to. lift one spreader out of action and lower the other one into action ; the scrapers 56, 58 may also be inclined to impart forward movement to the material. This subject-matter does not appear in the Specification as accepted.