| 摘要 |
572,087. Ships' davits. MAPPIN, W. L. March 10, 1944, No. 4463. [Class 115] A ship's davit is pivotally and slidably mounted within a frame and means are provided first for rocking the davit upon its pivot, and then for rocking the davit upon its pivot and moving the pivot within the frame. In the form shown, each davit 20 is pivoted on a shaft 18 having rollers which run on guides 9 on a frame 5 with bearers 7 between which is slidably mounted a rack 11 on rollers 12, the shaft 18 being moved by a cross-head 16 and cables 75, 76 which pass around sheaves 77, 78 on the frame 5, sheaves 13, 14 on the rack 11, and a drum 65. The davit 20 has a toothed quadrant 22 to engage the rack 11 and a curved arm 26 carrying sheaves 28, 29, 29A and 30, and a pair of fall blocks 32 for the boat 34, the falls 35 extending from an eye 36 on the frame 5 and through a block 38 to a cleat. The boat is normally -held in an inboard position by a cinch rope 39 which extends from the extremity 40 of the arm 26 to an eye 42, a snatch hook 43 being provided for quickly releasing it. The hook 43 also releases a short cable 45 on the arm 26. Formed partly within the frame 5 is a housing 50 for a compound gear train 51 with a crank handle 54, a brake drum 56 with a centrifugal governor 57, and the cable drum 65, the brake band 68 being actuated by a heavy lever 69. After the hook 43 is opened, the brake band 68 is released by the lever 69 and the weight of the boat tensions the falls 35 to pull the davit to the position S, and the rack 11 recedes inboard. Continued motion of the gear train 51 will then allow the cross-head 16 to travel forwards along the guides 9, the quadrant 22 rolling forwards along the track 11 until the davit reaches the position T. In a modification described and illustrated in the Specification, the gearing 51 is dispensed with and a single rope controls the two movements of the davit. |
