GB890982A - Safety device for trip dog actuated needle mechanisms in hay balers - Google Patents

Abstract

890,982. Baling-machines. WILLIAMSON, G. A. July 4, 1960, No. 23231/60. Class 94(1). The invention relates to a safety device for hay baling machines of the kind in which hay is compressed in a bale chamber by a plunger and in which needles move across the path of the plunger in a tying operation. In such machines, the needles and the tying mechanism can be actuated when a circular member 8 is clutched into a driven relationship with a rotating clutch housing 1. Such clutching is normally performed when a hay metering device depresses a lever 13 and permits a trip dog 4 to be released from a position in which it holds a spring biased roller 3 away from the path of an internal clutch or driving lug 2 in the rotating clutch housing 1. When this occurs, the driving lug 2 on the rotating clutch housing 1 engages the roller 3 and causes the circular member 8 to rotate with the clutch housing. The release of the trip dog 4 at an instant when the lug 2 is in close proximity to the roller 3 can result in the roller 3 bouncing off the lug 2, after having initiated actuation of the needles, and it is then necessary for the rotating clutch housing 1 to perform another revolution before positive drive-connection is made between the lug 2 and the roller 3 to operate the tying mechanism, during which time a plunger stop dog may come into action with the resultant shearing of the conventional safety shear bolt in the flywheel of the drive source. To prevent this occurrence an external cam is mounted on the periphery of the rotating clutch housing, this cam co-operating with means preventing the trip dog 4 from being released except when the roller 3 and the lug 2 are in a predetermined position. As shown an additional pivoted lever 22 is provided, this lever having latch means 24 that holds the trip dog 4 against release, independently of the lever 13, until it is depressed by a cam 21 on the rotating clutch housing. Alternatively, the cam 21 could be so profiled that it operates the pivoted lever 22 such that it holds the latch means 24 away from the trip dog except during the danger period.