US1624535A - Stair square - Google Patents

Description

c. A. cHRls'rlANsoN STAIR SQUARE Filed May 26, 1925 Patented pr. l2, 11927.

UNITED STATES PATENT OFFICE.

STAIR SQUARE.

Application filed May 26, 1925. Serial No. Y33,073.

The present invention relates to a stair square which may be used to obtain the length, treads, and rises between the walls and stair stringers, and in building circu- '5 lar stairs, it may be used as a bevel square at both ends. rThe device is t'urther useful in obtaining the length and niiter cut .of balusters between the top and bottoni rails.

In the drawing,

Figure 1 is an elevation of the device extended,

Figure 2 is an elevation of the device folded,

Figures 3 and 4 are sections taken on the lines 8-3 and 4-1 respectively of F ig. 2,

Fig. 5 is a section through the hinged joint.

Referring to the drawings in ldetail, it

will be seen that the numerals and 5 denote a pair ot' bars, hingedtogether as at b' so that they may be swung to the positions shown in Figs. 1 and 2. The hinged joint 6 is constructed to limit the swinging orn one bar-with respect to the other in van arc of 180". The bars 5 and have longitudinally extending slots 7 and 7 respectively t'or receiving bolts 8 and 8 on which are threaded thulnb nuts 9 and 9. Bars 10 and 10 are pierced at Vone end by the bolts 8 and 8 respectively and have Inortises to slidably receive bars 5 and 5 respectively. Plates 11 and 11 are pierced by the bolts 8 and 8 respectively and eX- tend over the bars 5 and 5 respectively and 35 bars 1()y and 10 respectively. Blades 12 and 12 are formed at one end with slots 14 and 14 respectively. The slotted ends ot' the blades 12 and 12 extend between the plates 11 and 11 respectively and the bars 40 10 and 10 respectively and the bolts 15 Y and 15 pierce openings in the plates 11 and 11 respectively, and the bars 10 and 10 respectively and also the slots 11 and 11 respectively. Thumb nuts 16 and 16 are 45 threaded on the bolts 15 and 15 respectively. The `free extremities ot the blades are beveled. y

Having thus described niy invention, what I clailn as new is:

A device of the class describedincluding a pair of hinged bars, a second pair otl bars slidable on the first pair of bars, means limiting the sliding ot' the bars in relation to one another and operable to hold the bars in different adjusted positions, plates on the second bars and extending over the iirst bars, a pair ot' blades, and adjustable pin and slot connections-between the blades and the second bars and the plates.

CHRIST A.v CHRISTIANSON.

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