US1422925A - Proportional scaling instrument - Google Patents

Description

atented July i8? N22i,

J. D. CARTER. PROPORTIGNAL SGALING INSTRUMENT.

APPLICATION FILED FEB. 11, i921.

JAMES D. CARTER, 0F CHICAGO, ILLINOIS.

PROPGRTIONAL SCALENG INSTRUMENT.

Specification of Letters Patent.

Patented Jarvis, 1922.

Application filed February l1, 1921. Serial No. 444,131.

To all whom t may concern.'

it known that l, JAMES D. CARTER, a citizen oi the United States, residing at Chixago, in. the county of Cook and State of illinois, have invented certain new and useiul -linprovements in Proportional Scaling u.instVui'nents,V oiE which the following is a specilication. y

rlhis invention` relates to a scaling instrument primarily designed Jfor drafting purposes, although the mechanism shown is equally adapted tor use in connection with machinery or tools sed tor engraving, routing, carving, or other operation which requires the employment of a multiplicity of marking or cutting tools adapted to operate vin unison and in a space ratio with one another.

The primary object of the invention is to provide a mounting for such tools or instruments, together with suitable adjustment mechanism, so that the several tools may be simultL neously adjusted to different positions without altering the spacial ratio between the respective tools or instruments, thereby at all times maintaining a predetermined spacial ratio irrespective of the scale chosen for the operations. The invention is one which permits the several too-ls or instruments to be individually adjusted to the desired ratio with respect to one another, and thereafter permits the entire series of tools to be adjusted as a group to any scale desired without interfering with the space ratio of the individual units. This arrangement permits the use oit a master pattern of given size to be employed as a guide for the scaling therefrom oft one or more copies drawn to a different scale, and the device illustrated is usable under any conditions where such a scheine ot operations is required.

'lin the 'torni shown Yfor purposes oit exemplilication, the device is illustrated as a drafting instrument. but it is obvious that the marking mints shown might be replaced by carving or cutting instruments, actuated by power, ii desired, without in any way alizering the mechanism employed for maintaining the ratio between the parts.

The invention consists inthe features ot construttion and combinations of parts hereinafter described and claimed.

In the drawings:

Figure l is a side elevation of the device;

Fig. 2 is a plan View of the same;

Fig. 3 is a cross sectional, view of 4the swivel head; i

Fig. e is a cross sectional view of one of the riders and associated kparts;

l? ig. 5 is an end view of one of they riders; undr l Fig. 6 is a sectional detail oit the mounting lor the s'wiveled head.

The device comprises a pair of parallel guii'le rails i0 and ll united at the outer end by a cross head l2. The guide rails and cross head are preferably formed of a stili steel rod bent to the required configuration, and the inner ends of the rails are preferably soclreted within upper andlower parallel socket holes in `a swiveled head 13, which, as shown, is of generally rectangular formationu The ends of the guide rods may be brazed or otherwise permanently secured in place within the head, although it is preferred to provide means whereby 'these parts may be disassembled. As shown suoli means comprise a clamping plate l-t which is entered within a 'vertically arranged recess l5 in the swiveled head. The clamping plate, as shown in Fig. 3, is arranged to bear against the sides of the guide rods, and a threaded stem 1G is provided which extends freely through the clamping plate, and is threaded at its outer end to receive. a thumb nut l? which bears against the clamping plate, so that-a turning of the thumb nut will draw the latter tightly in contact with the contiguous portions of the upper and lower rails, thereby clamping the same tightly in position.

rlhe swiveled head is mounted upon a post i8, which, at its lower end, `carries a cross trunnion i9, the ends of which are socleted within a recessed swiveled plate 2() which is n free to rotate within a recessed base plate 2l` shown in Fig. Gp The cross trunnion 19 is disposed in transverse'relation to the guide trame, sothat the latter may be raised and lowered, or turned around the axis oi the swiveled post 1.8 as a center, but is held against 'tipping or tilting in a sidewise direction.

rlhe swiveled head i3 co-operates with a slidably mounted outer head 22 which rides upon the upper and lower guide rails, and is provided with a clamping plate 23 and a thumb nut 24 similar to those ypreviously described. The outer head 22 ca ries a marker which, however, may obviously be replaced by a stylus, drill, router or other drill or instrument, these parts being removable by the loosening oi a set screw 25a or the like. v

Between the swiveled head and the outer head is mounted an elastic adjusting element 26 which, in the torni shown, consists preterably of a coiled spring ot uniform tension throughout. ills shoxvn, the ends ot the coiled spring are ixedly secured to the swiveled head and outer head respectively, so that the latter may be adjusted to varying positions upon the guide trame rand atterwards clamped in position by means of the thumb nut 2li, thereby expanding the elastic element--spring or the likef-to a greater or less degree ot expansion. :is shown, the ends oinv the spring are threaded onto socket holes 26 and 27 1n the oppositely disposed heads which affords a convenient and satisfactory method ot securing these arts together, although obviously other suitable or convenient means might be provided tor securing the parts together.

Between the tivo heads are mounted one or more riders 98, tivo being shoivn for purposes of illustration, Which riders are provided With upper and loiver guide holes 29 and BO through which the guide rods eX- tend, the arrangement being one 'which permits the riders to slide smoothly and evenly along the guide rods Without cramping or binding, and at the same time serves to maintain the riders against vibration or displacement when brought to the intended position. Each ot the riders is provided with means 'lor clamping the same securely to the elastic element, a suitable and convenient 'form being shown for purposes ot illustration. As shown` each ot' the riders provided through its center with a hole or bore Ell ot' a size to permit the spring or other elastic element to pass therethrough and the rider is also provided on its interior ivith a recess 32 within which is housed a split spring clamping ring which embraces the coiled spring or other elastic element, the tree ends oit the split spring ring havingl entered therethrough a draw stem 34 threaded at its outer end and provided with a thumb nut 35 adapted to dran1 the tree ends olf the split spring ring together, so as to tightly clamp the parts together. The split spring clamping ring being closely housed Within the recess in the rider will prevent any 'tore and att movement oii the parts when clamped together.

ln order to more eilectively prevent any accidental movement ot' the parts, means are provided tor clamping the rider onto the rails of the guide trame. and a convenient means i'or this purpose consists ot a plate 36 provided with inwardly extending clamping lingers BT which bear against the upper and lovver guide rails and are adapted to be aeeaees brought into clamping engagement therewith by means ot a thumb nut 38 threaded onto a stem 39, vchich latter passes treely through the clamping plate 36 and is threaded or otherwise rigidly entered into the contiguous vfall ol the rider. Each ot the rriders is provided with a marking tool e0 or other requisite tool or instrument depending upon the use for which the device is intended.

ln use, one or more riders can be mounted in position upon the guide rails by removing the lat" trom the svviveled head and passing the riders onto the rails and spring, atter which the ends ot the rails are entered and clamped within the svviveled head. Assuming that tivo riders are to be employed, the same will be adjusted to the desired positions, so that the intended space ratio ot the several marking or cutting instruments will be established, after which the riders will be tightly clamped to the coiled spring or other elastic. element by tightening the clamping ring or rings rlfhereatter the entire series may be adjusted as a unit by moving the outer head to the desired position, and this ivill result in automatically repositioning` the riders without disturbing the space ratio between the several parts, since each portion oi" the elastic element will elvgand or contract in unii'orm ratio `with every other portion. lt is thus evident that it an initial adjustmento'fthe parts in the ratio oit 2. l and 6 inches trom the pivot point be established, and it thereafter the outer head be moved to the distance ot l2 inches .trom the pivot point, the riders will automatically assume positions in the ratio ot l and 8 inches troni the pivot point Vwithout individual zidjustnient, and Without the necessity for making individual computations contormable to the newly established scale ot operations.

The instrument can `be readily used 'for drafting purposes` vvhere concentric circles are to be drawn in given ratio 'to one another,irrespcctive ot the scale chosen, since valter the space ratio ot the parts is once established.. the outer head can be adjusted to any radius desired, and the established ratio ot the smaller circles vvill be maintained. ln like manner, the instrument can be used tor producing plurality ot' similar figures di'ltering in scale from a master ligure orpattern, or for like operations on the drafting board, and can also be employed tor like purposes on carving machinery, engraving n'iachinery, or Vtor other purposes of like character.

The principle ot this invention is one 'which lends itselt readily for use in computing instruments in which visual indication rather than inscribed lines are adequate to give the desired data. Yit' so used it is evident that the fixed portions of the device nould be suitably scaled or marked in con- Iormity with the system of measurements hosen for purposes of computation as indicated on the top guide rail in Figs. l and 2.

Although the invention has been described with considerable particularity as to detail, it will be understood that the details of construction may be varied or modified without departing from the spirit of the invention. I claim:

i. In an instrument of the class described, the combination of a frame, a longitudinally extensible and contractible elastic element, relatively adjustable members carried by the frame to each of Which the elastic element is secured, an element intermediate the relatively adjustable members and secured to the elastic element, and Working instruments one of which is attached to one of the adjustable elements, and one of which is attached to the intermediate element, for the purposes set forth.

2. ln an instrument of the class described, the combination of a guide frame, an element lined to the frame, an element slidably adjustable on the frame, an elastic element secured to the fixed and adjustable elements, an element intermediate the fixed adjustable c elements and slidably mounted on the guide trame, and means operable from the side of the instrument for securing the intermediate element to the elastic element in a predetermined spacial ratio between the fixed and adjustable elements, for the purposes set forth. l

3. ln an instrument of the class described, the combination of a guidevvay, an element fixed on the guideway, a swiveled mountingfor the fixed element, an element adjustable on the puideway, an elastic element secured to the fixed and adjustable elements, a rider intermediate the two elements and slidably mounted on the lguidevvay, means for clamping` the rider to the elastic element in any desired position of adjustment, and Working instruments carried by the adjustable element and the rider respectively, for the purposes set forth.

Ll.. ln an instrument of the class described, the combination of a guideway, an element fixed on the gjuideway, an element adjustable ou the `guidewajg an elastic element secured to the fixed and movable elements, a rider `upon the guide rails and adjustable-to any desired position, an elastic element connecting the head and movable element, means for clamping the movable element in adjusted position upon the `guide rails, a rider slidably mounted upon the guide rails, means for clampingthe rider to the elastic element in any desired position of adjustment, means for clamping the rider to the guide rails, and Working tools carried by the movable element and rider, for the purposes set forth.

6. ln an instrument ofthe class described, the combination of a bead, a swiveled mounting` therefor, parallel upper and lower guide rails carried by the head, a' movable element slidable upon the guide rails, means for clamping the movable element upon the guide rails, a. uniform elastic element connecting the head and movable element and lying within the space between the guide rails, a rider slidably mounted upon the guide rails, means for clamping the rider to the elastic element in any desired position of adjustment, means for clamping the rider to the guide rails, and Working tools carried by the movable element and the rider, for the purposes set forth. f

7. ln an instrument of the class described, the combination of a head, a swiveled mounting` therefor, parallel upper and lower guide rails carried by the head, a movable element' slidable upon the guide rails, means for clamping the movable element upon the guide rails, a uniformly elastic element connecting the head and movable element and lying' Within the space between the guide rails, a rider slidably mounted upon the guide rails, means for clamping the rider to the elastic element in any desired position of adjustment, and Workin@` tools carried by the movable element and the rider, for the purposes set forth.

JAMES D. CARTER.

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