| 摘要 |
586,618. Work holders. BRYANT, L. A. Nov. 7, 1944, No. 21860. [Class 83 (iii)] A work-holder for use in assembling structures such as parts of aircraft comprises horizontal and vertical straight edges which are adjustable on a rigid frame so as to support in the required position a jig in which the assembly is to be made. In one form, the rigid frame comprises vertical pillars 1 tied by cross-members 2 which carry supporting bars 3, 4 for the jig 5. Longitudinal straight edges 8, 12 are attached to the pillars 1 by brackets 7, 11 and serve as supports for vertical straight edges 15 attached thereto by brackets 16. Transverse straight edges 18 are mounted on the members 15 by brackets 19, all the members 8, 12, 15 and 18 having longitudinal slots to receive the securing bolts 17, 19, &c. The members 15 are set in the required positions by means of templates 26, Figs. 3 and 4, having a series of holes 25 by which they are temporarily attached to corresponding holes 24 in the members and an additional hole 27 whose position is determined by the lay-out of the part to be assembled in the jig 5. A removable pin 29 is inserted through the hole 27 and a hole 28 in the bracket 16, the latter is secured to the member 12 by a bolt 17, and the removable pin is then inserted through the hole 28 and a similar hole in the member 15 to position it whilst it is being secured by a bolt 32. Similar templates are used for positioning the members 18 on the verticals 15, a pin with a semi-cylindrical end being used for the brackets 19 of the members 18 so that the diametrical flat side of the pin may engage the top surface of the bracket. Another similar template is used for locating a fixture 55, Fig. 11, on a member 18, this fixture carrying a pin 59 engageable with a screwed stud 57 which is secured in a socket 60 welded to an upright 58 of the jig 5. The stud may be secured in the socket by welding or by pouring thermosetting material such as a low melting point alloy in the socket through a hole 62. In a modified construction, each member 8, Fig. 15, is carried by brackets 87 secured to a beam 81 mounted on vertical posts' 1 resting on a concrete base 80, whilst the members 12 are carried by brackets 85 supported on a plate 84 which rests on beams 83 embedded in the concrete. Each member 8, 12 is adjusted by differentially threaded pairs of screws 90, Fig. 16, and lock-nuts acting in a horizontal direction and by similar single screws 95 acting in a vertical direction. |
