Патент USA US2107670код для вставки
Feb. 8, 1938. 5.o, KARLsoN 2,107,670 DEVICE FOR GAUGING THE CUTTING OF' RAFTERS Fiìled Feb. 1 8. 1937 Z3 l BY *ÉÍMÄPW ATTORNEYS ‘Patented Feb. 8, 1938 2,197,670 UNITED STATES PATENT OFFICE 2,107,670 DEVICE FOR GAUGING THE CUTTING OF RAFTERS Erik 0. Karlsen, Elmont, N. Y. Application February 18, 1937, Serial No. 126,348 3 Claims. This invention has relation to carpenters’ im plements and comprehends an improved device for facilitating the computation or determination of the lengths and angles of rafter cuts. The invention broadly aims to provide a device vaverage carpenter may expeditiously compute I9 are also inscribed on the upper surface I3 and 5 said lines are parallel to each other and to the line I4. The line I8 has associated therewith and with the aid of the usual steel square mark the lumber for the various cuts to be made in indicia 2E) which is here designated “common rafter”, while the line I9 has associated there~ of the indicated character by means of which the 10 Aiashioning common rafters, hip and valley raft ers, and jack rafters. More particularly the invention resides in a device of the character set forth and for the purpose specified which includes a base having graduations, lines and indicia on one surface thereof and cooperative graduated sliding and swinging members adjustable to positions coin o , transverse line I5. The line I4 is subdivided by longitudinally spaced graduations I6 having as sociated indicia Il beginning at the line I5. A pair of longitudinally extending lines I8 and ciding with the building and roof measurements to compute and determine the lengths of the various rafters and the heel, plumb and angle cuts to» be made. Other objects of the invention reside in the provision of a device of this character which is comparatively simple in its construction and mode of use, inexpensive to produce, highly ef 2.ai ficient in its purpose and which is small and compact whereby it may be readily carried in the carpenter’s kit or pocket. With the above enumerated and other objects >in view, reference is now made to the following 3 specification and accompanying drawing in which there is disclosed a preferred embodiment of the invention, while the appended claims cover variations and modifications thereof which fall ` 3 Cl . within the scope of the invention. In the drawing: Fig. 1 is a face view of the device constructed in accordance with the invention, illustrating the slide member and pivoted arm in adjusted set position. Fig. 2 is an end edge view thereof as viewed from the left hand edge of the device. Fig. 3 is a face view illustrating the slide mem ber and pivoted arm in folded inactive compact 45 position for storage of the device. Fig. 4 is` a vertical sectional view taken ap proximately on. the line 4--4 of Fig. 3. Referring to the drawing by characters of ref~ erence, Ill designates the base of the devicel which 50 is preferably of rectangular configuration hav ing parallel opposite longitudinal side edges Il and I2 and a plane upper surface I3 which is provided with a longitudinally extending line I4 adjacent to and parallel with the side edge I2 56 and adjacent one end edge with a perpendicular with indicia 2l, here designated “hip or valley mi rafter”. The line I4 together with its gradua tions I5 and indicia I'lhas further indicia 22 as sociated therewith designated the “rise”, A slide member designated generally by the reference character 23 is mounted for guided 1P sliding movement with reference to the base I0 and said member 23 is preferably of T-shaped construction having a longitudinally extending head 24 which is formed with a groove 25 in its inner edge to slidably fit over the side edge I2 of the base. The slide member 23 further in w i cludes a slotted arm 26 disposed at an angle to the head 2li and extending transversely of the base I0 with the base received by the slotted por tion so that the arm 26 straddles the same, and the upper surface of the portion of the arm 26 which overlies the base is provided with a series of graduations 2l which start at the line III and extend throughout its length to the free end thereof. Indicia 28 is associated with the graduations and the arm 26 is also provided with in dicia 29 designated the “run”. In order to lock the slide member 23 in adjusted relation to the base, a set screw 30 having a knurled manipulat ing head 3l is threaded through the outer end edge of the slide arm 26 and is designed to be 35 impinged against the side edge'l I of the base. The device further includes a swinging arm 32 which is mounted to swing on a pivot 33 having a vertical axis located at the intersection of the lines i4 and I5 adjacent one corner of the base, the edge 34 of the swinging arm intersecting the axis of the pivotal connection of the arm and said edge being provided with a line of graduations 35 and associated indicia 3S starting at the pivotal point of the arm. The arm is disposed between the resilient fur cations of a bracket 3l and the arm is secured in adjusted angular position by means of a thumb nut 38 which threadedly engages the pivot 33 for 50 frictionally clamping the arm between the furca tions. In order to limit the swinging of the arm 32 to a position parallel with the head 24 of the slide member, a clip 39 is provided on the head 24 of the slide member. 56 2v 2,107,670 The upper plane surface I3 of the base is pro eighths” inches which combined with the base vided with curved lines 4D and 4I which extend graduation at the intersection of the slide arm from the axis of the pivot 33, diverge with refer 26, is “eleven and one-quarter” inches. The ence to each other and terminate at the oppositeY end edge of the base. These curved lines are re spectively designated by the indicia 42 and 43 as “bevel for hip or valley rafter” and “bevel for jack rafter”. In use and operation, when it is desired to de 10 termine the length of a common rafter and the angle ofthe heel and plumb cuts thereof, the slide is first moved so that the graduated edge of the slide arm coincides with the graduation I6 and indicia Il corresponding to the rise of the rafter is obtained by reading the base graduation which shows “eleven and one-quarter” inches and the slide graduation at the intersection of the curved line marked “bevel for jack rafter” which 15 roof. Y The set screw 30 is then tightened to re is found to be “eight and one-quarter” inches. . square. The plumb cuts at the opposite endsV of the jack rafters are the same as thaplumb cuts for the common rafter and the bevel of the lower plumb cut which is to rest against the side of the valley tain the adjustment and the swinging arm 32 is In order to determine the length of the valley then swung to a position where its graduated edge coincides with the graduation 2l and indicia 28 which corresponds to the “run” which is half the width of the building. The graduation 35 and rafter, adjust the swinging arm 32 to the point of intersection of the graduated edge of the slide indicia 35 on the swinging arm 32 at the point of intersection of the graduated edges of the arms 26 and 32 will give the length of the rafter. By use of the usual carpenter’s steel square, the an gles of the heel and plumb cuts and the bevel cuts for roofs of equal pitch are obtained as fol lows: Assuming that the run is “fifteen” feet and the rise “fourteen” feet, first set the slide mem ber at the base graduation I6 indicated by the indicia il as “fourteen”, then tighten the set screw 3l?. The swinging arm 32 is then adjusted u steel square is then laid on the edge of the lum ber and marked along the tongue of the steel arm with the line i9 designated “hip or valley rafter” and tighten the clamping nut 38. Then 20 move the slide to the base graduation I6 which corresponds to the rise of “fourteen” feet and read the graduation 35 on the swinging arm 32 at the point of intersection of the graduated edge of the slide arm 26 with the swinging arm 32. 25 This, in the example being given, will show “twen ty-ñve feet, six inches”. To determine the difference in length between the common rafter and the ñrst jack rafter, move at an angle where its-edge 34 intersects the grad uated edge of the arm portion 26 of the slide the slide arm 26 to the base graduation “eleven 30 and one-half”, set therrswinging arm 32 yto the point of intersection of the line 4|, designated “bevel for jack rafter”, tighten the swinging arm member 23 at the graduation 21 which corre spends to the run, namely “fifteen” feet. The in this position and then move the slide arm, 26 to the point where it intersects the edge 34 of graduation 35 indicated by the indicia 36 on the swinging arm 32Will indicate the length of the common rafters, namely “twenty feet, six and ione-half” inches. For the purpose of obtaining the heel and plumb cuts so that the graduation the swinging arm 32 at the graduation 2l on the slide arm which corresponds to the spacing of the jack rafters, which spacing has been pre~ determined, say for example, as “sixteen” inches apart. By then reading the graduation I6 and marked twelve on the blade of the steel square may be used as one measurement, tighten the clamping nut 38 to retain the swinging arm in indicia il on the base at the intersection of the set position and move the slide until the grad 45 uated edge thereof coincides with the intersec tion of the graduated edge 34 with the common rafter line i8 and tighten the set screw 30. ‘The swinging arm^32 is now released and» swung to the out-of-the-way position illustrated in Fig. 3 of the 50 drawing and the base graduation where the slide member arm 26 is now adjusted will givethe other reading as “eleven and one-quarter” inches for the steel square tongue. When the steel square is placedv on vthe lumber with the “twelve” inch 55 blade graduation at one edge of the lumber and the “eleven and one-quarter” inch tongue grad uation> at the edge of the lumber, the marking of the lumber along the edge of the blade will give the heel out while the marking of the lumber 60 along the edge of the tongue will give the plumb cut. To'determine the heel vand plumb cuts for the valley rafter, read the graduation at the point of intersection of the hip or Valley rafter line des 65 ignated i9, with the slide arm 26, and the read ing for the steel square will then be “eleven and one-quarter” inches on the tongue and “seven teen” inches on the blade, thelatter being the reading shown at the hip and valley rafter line. To determine the setting of the steel square 70 for the bevel cut of a hip or valley rafter, read the graduation on the slide arm 26 at the in tersectíon with the curved line designated “bevel for hip or valley rafter” which, in the example given, will be found to be “nine and ' three~ graduated edge of the slide arm, the difference in length between the common rafter and the first jack rafter, as well as between each of the succeeding jack rafters, will be obtained in inches and Will in the example given be “twenty-one and seven-eighths” inches. What is claimed is: ’ ~ ` l. In a device for computing rafter cuts, a base having a plane upper surface, a slide member 50 overlying and extending across the upper sur-` face of the base, vmeans mounting the slide mem ber for guided sliding movement lengthwise of the base, an arm pivoted adjacent one corner of the base, means for locking the slide member and 55 arm respectively in adjusted relation to each other, and curved lines on the surface of the base extending from the pivotal point of the arm for obtaining readings to determine the angle of the bevel cuts for the hip or valley and jack rafters. 60 2. In a device for computing rafter cuts, a rec tangular base having a surface inscribed with lines and indicia, a T-shaped slide member hav ing a slotted arm portion straddling and extend~ ing across opposite surfaces of said base, gradu 65 ations and indicia on the surface of the arm por tion overlying the inscribed surface of the base, a slotted head portion of said slide member en~ gaging over one edge of the base for mounting the slide member for guided sliding movement 70 lengthwise of the base, an arm pivoted adjacent one corner of the` base having graduations and indicia thereon, and means for locking the slide member and arm respectively in adjusted relation to each other, the lines on the surface of the base 75 3 2,107,670 being so arranged as to be- intersected by the slide member and the pivoted arm for designating the points of reading of the graduations to determine the length of common, hip and valle-y rafters and 5 the angles of the cuts to be made. 3. A device for computing rafter cuts including a base having a plane surface bearing a length Wise line having graduations for indicating the rise, a pair of parallel lines spaced therefrom and 10 from each other for use in computing the cuts of common rafters and hip or valley rafters re spectively, and divergent curved lines ,for use in computing the bevel cuts of the jack rafters and hip or Valley rafters respectively, a slide member overlying the surface of said base extending thereacross perpendicular to the parallel lines, mounted for guided sliding movement length wise thereof and having graduations indicating the run and cooperating With said parallel and 5 curved lines to compute said rafter cuts, a grad uated arm pivoted to said base at the intersec tion of the curved lines with each other and with the graduated line indicating the rise for the pur pose of computing the length of the rafters, and 10 means for locking the slide member and arm re spectively in adjusted positions. ERIK O. KARLSON.