US1106259A - Drawbridge. - Google Patents

Description

CLAUDE A.

Il?,` TURNER, OF MINNEAPOLIS, MINNESOTA.

DRAWBRIDGE.

Speeilieaton ot' Letters Patent.

Patented Aue'. et, 1914.

Application filed December 27, 1913. Serial No. 808,939.

To all who/m, it may concern i Be it known that I, @nanna A. l). TURNER, ot' Minneapolis, in the county of Hennepin, and in the State of Minnesota, have in vented' a certain new and useful improvement in Drawbridges, and` do hereby de! claro that the following is a fall, clear, and exact. description thereof My invention relates to draw bridges of the type shown in United States Patent No. 503,273, issued August 13, 1893, to l?. A. lil/*arnet* and myself, and the object of my invention is to improve the mechanism o't' that patent for raising the toggle joint for lifting the ends of the arms of the draw span preliminary to opening, or swinging the bridge. In that patent the apex of the toggle is connected by a transverse pin to the lower end of a vertically movable screw by the revolution of which the toggle joint is raised or lowered and there are certain objections to the construction which is the object more particularlyof my present invention to obviate.

My invention, therefore, relates particularly to the mechanism for imparting the desired vertical movement to the toggle joint.

lin the accompanying drawings- Figure 1 is a top plan view in the nature of a diagram showing a draw bridge of the type of that of the patent above mentioned; Fig. 2. is a side elevation thereof the full lines showing' the bridge in its `closed position and the dotted lines showing the posi tion of the parts when the toggle joint has been raised to lift the bridge `arms 'trom their bearings on the abutments; l*l 3 is a detail View in vertical section of the toggle joint lifting mechanism; Fig'. 4 is an end elevation thereof with parts in section; Fig. 5 is a top plan view thereof. I

ln its general construction, as may be seen by reference to Figs. 1 and 2,; the drawbridge shown corresponds to that of said Patent No. 503,273, that is to say, .the bridge is mounted upon a central t'urny table 10 which supports the two oppositely extending arms 11., said arms having at tiroir inner ends struts 12 which at their point of connection with the top chords of the arms at their upper ends are connected tothe outer ends of the toggles 13, the inner eiids ot' the toggles being brought together anld lapped past each other and connected byl a transverse pin let, the holes in the toggle eyes being horizontally elongated to allow for the necessary play upon the pin due to the vertical movement oi" the toggle joint.

The toggle pin 14; rests in a semi-circular bearing in the top of a saddle 15, which at cach side of the pin has a horizontal extension 16 with an internally threaded hole through which passes a vertical screw 17, the two screws being, respectively, right and lett handed and suitable bearing being provided in the trame work 18. Upon each of the screws 1T is keyed, or otherwise secured, a gear 1S) and between the two gears 19 and meshing with both of them is a pinion 20 upon a vertical operating' shaft 21 by the revolution of which, either by hand or by power, the screws are simultaneously revolved in opposite directions and the saddle thereby caused to move vertically and the togajgle joint thereby raised when the direction of the revolution of the screws is such as to move the saddle and the toggle pin 14: thereon upward. lt will be seen that by the employment of the two screws there is no torsional or twisting effect whatever upon the pin 1-14 which results from the single screw and nut arrangement of the construction of the patent before mentioned, and hence, tendency of the latter to bind in the guides S32 between which the pin at its opposite ends project, is avoided, so that the toggle pin 11i moves upward smoothly and freely without any bindingl tendency from sidewise or lateral movement; and it will be seen that in other respects my present toggle joint lit'tn.: mochanif-nn is desirable in that it. is simple, its members being of the simplest hind, and it is easily operated and powerful.

Having thus described my invention what l claim is- 1. As an imjn'ovement in end lifts of center bearing draw bridges, the combination ot a toggle, a toggle pin at the joint, a pair ot rotary screws at opposite sides of the tognle pin, connections between the screws and the togg e pin, and means for revolving said screws.

9.. As an improvement in end lifts of centcr bearing draw bridges, the combination ot' a oggi@ a toggle pin at the joint, a pair oi rotary screws at opposite sides of the toggle pin, connections between the screws and the toggle pin, and means for revolving said screws, the screws having, respectively, right and left thread.

As an improvement in end lifts of screw passing through each opening, said screws having right and left thread, gears on the respective screws, and a driving pinion between `the two gears meshing with 15 both of them.

In testimony that I Claim the foregoing I have hereunto set my hand.

CLAUDE A. P. TURNER. litnessesz HENRY I. CHURCH, B. NV. ADAMS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C."

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