US3280466A - Compasses with improved adjustment means - Google Patents

Description

Oct. 25, 1966 H. HEIMBERGER 3,

COMPASSES WITH IMPROVED ADJUSTMENT MEANS Filed July 27, 1964 2 Sheets-Sheet l INVENTOR H. Heimberger Oct. 25, 1966 H. HEIMBERGER 3,280,466

COMPASSES WITH IMPROVED ADJUSTMENT MEANS Filed July 27, 1964 2 Sheets-Sheet 2 INVENTOR H. Heimberger United States Patent 3,280,466 COMPASSES WITH IMPROVED ADJUSTMENT MEANS Helmut Heimberger, Essen (Ruhr), Germany, assignor to Clemens Riefler Fabrik Mathematischer Instrumeute, Postfach, Germany Filed July 27, 1964, Ser. No. 385,122 Claims. (Cl. 33-154) This invention relates to improved drafting instruments and, more particularly, to compasses of the type having a spindle and associated screw member arranged to adjust-ably connect the arms of the compass to one another; the improved arrangement being such that a rapid major adjustment of the arms can be made without turning the adjustment screw, said adjustment screw serving primarily to make fine adjustments.

Various forms of compass and drafting instrument adjusting mechanisms have been suggested heretofore. As a general matter, when the adjusting mechanism has included a spindle and associated screw member, every adjustment (whet-her large or small) has required turning of said screw member until the new desired radius, or relative arm positions, have been achieved. As a result, prior compasses of this general design have permitted fine adjustments only by means of the spindle, without any possibility of the compass arms being moved in a rapid major adjustment; and the operation of such known com-passes has, therefore, been difficult and timeconsuming. The primary object of the present invention, recognizing this situation, resides in the provision of improved form of adjusting mechanism, for use on compasses or other instruments of the general type described; so arranged that, in addition to fine adjustments, a rapid major adjustment becomes possible.

The invention effects this improved operation by providing an adjusting mechanism which includes at least one nut, constructed and arranged to be resilient in its radial directions within the range of its thread, in association with a spindle having a thread adapted to effect a radial distortion, or resilient pushing-away, of the nutthread when the compass arms are manually expanded and compressed relative to one, another. The improved structure of the present invention thus makes it feasible to effect a rapid major adjustment, of the arms of the compass, prior to a fine adjustment there-of, simply by expanding or compressing the compass arms. By such manipulation of the compass arms (or of similar adjustably interconnected parts of other instruments), the thread of the nut (or of both nuts if such nuts are arranged within both arms of the compass) will be resiliently distor-ted, thereby to permit a rapid major adjustment of said arms or interconnected parts; and fine adjustments can thereafter by made by turning the spindle. Thus, the instruments contemplated by the present invention can be precisely adjusted in a much shorter period of time than has been possible heretofore.

In order to facilitate movement of the spindle within the aforementioned resilient nut, or nuts, respectively, the spindle can be provided with a knuckle or a buttress thread. The nut, 01' nuts, can be made from any apppropriate resilient material, either natural or synthetic; but preferably comprise a resilient homogeneous substance fabricated on the basis of the polyester-isocyanate additive reaction. As will also appear, the nuts can be provided with a preformed thread adapted to be engaged by complementary threads on the spindle, substantially free from play; or, in the alternative, the resilient nuts can also be made with an unthreaded bore, which bore has a diameter smaller than the outer diameter of the spindle, so that as the spindle is screwed into the said bore, it forms a counter-thread in the nut, or nuts, with which said spindle is associated.

The term resilient materia is used herein, and in the appended claims, in its normally accepted sense, i.e. it refers to the capability of a material to elastically deform temporarily upon the application of forces thereto, and, upon removal of said forces, to return to its original position, shape and size.

The foregoing objects, advantages, construction and operation of the present invention will become more readily apparent from the following description and ac companying drawings, in which:

FIGURE 1 shows one form of compass constructed in accordance with the invention;

FIGURE 2 shows another form of compass constructed in accordance with the invention;

FIGURE 3 is a cross-sectional view of a portion of the right-hand arm of the compasses illustrated in both of FIGURES 1 and 2;

FIGURE 4 is an end view of the structure illustrated in FIGURE 3;

FIGURE 5 is a cross-sectional view illustrating a portion of a compass or instrument arm constructed in accordance with a further species of the present invention;

FIGURE 6 is an end view of the structure shown in FIGURE 5;

FIGURE 7 is a detail view of a portion of a spindle adapted for use in the present invention and having a buttress thread;

FIGURE 8 is a detail view of a portion of an alternative spindle adapted for use in the present invention and having a knuckle thread;

FIGURE 9 is a cross-sectional view illustrating a portion of a compass or instrument arm constructed in accordance with still another species of the present invention;

FIGURE 10 is an end view of the structure shown in FIGURE 9;

FIGURE 11 is a cross-sectional view illustrating a portion of a compass or instrument arm constructed in accordance with a still further species of the inveniton;

FIGURE 12 is a cross-sectional view illustrating a portion of .a compass or instrument arm constructed in accordance with still another species of the present invention;

FIGURE 13 is an end view of the structure shown in FIGURE 12;

FIGURE 14 is a cross-sectional view illustrating a still further species of the present invention;

FIGURE 15 is a cross-sectional view of a portion of an arm corresponding to still another species of the present invention; I

FIGURE 16 is an end view of the structure shown in FIGURE 15;

FIGURE 17 illustrates still another species of the present invention;

FIGURE 18 is an end view of the structure shown in FIGURE 17;

FIGURE 19 illustrates a still further .species of the invention;

FIGURE 20 is an end view of the structure shown in FIGURE 19; and

FIGURE 21 is a top cross-sectional view of the structure shown in FIGURE 19.

The compass illustrated in FIGURE 1 has a head structure 2 provided with a handle 1, and having a pair of arms 3- and 4 swivel-mounted within said head structure 2. The compasses can be provided with any desired type of guide structure for causing the handle 1 to be located at all times along a line bisecting the angle formed by the two arms 3 and 4. Arm 4 is provided with a recess 5, as shown in FIGURES 3 and 4, into which is inserted a nut 6. The contact areas 7 and 8 of the recess 5, as well as the corresponding areas of nut 6, are circular segments so that the nut 6 is adapted to pivot within the recess of said arm 4. A spindle 9 passes through nut 6, spindle 9 being provided with either a buttress thread, of the type shown in FIGURE '7, or with a knuckle thread of the type shown in FIGURE 8. Nut 6 has two generally parallel surfaces 10, spaced from one another by a distance less than the distance between the edges 11 of the recess 5. The said nut 6 may be mounted in recess 5 of arm 4 by initially inserting the nutinto recess 5 in such manner that the said parallel surfaces extend generaliy in the direction of extension of arm 4, whereafter the nut 6 is turned until it reaches the position shown in FIGURE 3. Nut 6 can consist of a resilient material, for example, a resilient synthetic material, preferably a resilient homogeneous substance fabricated on the basis of the polyester-isocyanate additive reaction. Said resilient nut 6 can also be provided with an internal thread of one of the types shown in FIGURES 7 and 8, so that the thread of said out may be engaged, free of play, by a cor-responding thread on the spindle 9.

The other arm 3, in the species of compass depicted in FIGURE 1, is also provided with a recess similar to recess 5 of arm 4, into which recess is inserted a component 6 designed in the same manner as the nut 6 but provided, in place of a thread, with a through-bore in which the spindle 9 is rotatably but not axially movable. Moreover, in the species of FIGURE 1, the left end of the spindle 9 is provided with a knurled knob 12 which facilitates the turning of spindle 9.

In operation, when it is desired to make a rapid major adjustment of the compass shown in FIGURE 1, it is merely necessary to physically move the arms 3 and 4 toward or away from one another. When the arms 3 and 4 are so manipulated, the thread of the nut 6 is pushed away or distorted resiliently in radial directions by the spindle 9, thereby in effect permitting the nut 6 to slide relative to the spindle 9. After a major adjustment of this type has been accomplished, the distance between the compass points can then be precisely set by turning the spindle 9 through the agency of knob 12.

Obviously, it is also possible to provide nut 6 with a through-bore having a diameter smaller than the outer diameter of the spindle 9, so that the spindle will cut its town thread when screwed into the bore. The operation of the instrument still corresponds to that described above.

In order to achieve symmetrical movement and positioning of the two compass arms with respect to the head of the compass, the compass of the present invention is preferably provided with a guide member, e.g., the spindle may be provided, at its center, with a circular knurled disk which is guided within a slot defined in the head of the instrument. Thus, in the species of compass illustrated in FIGURE 2, resilient nuts 6 are inserted in both arms 3' and 4' Within appropriate recesses 5, these nuts being engaged by a spindle 9, provided with either a buttress or a knuckle thread, as depicted by FIGURES 7 and 8. At the center of spindle 9' there is fastened a knurled disk 12' which is guided within a slot 13 formed in an extension of head member 2' whereby a straight-guidance is accomplished, and symmetrical movement of arms 3', 4' is assured. When the two arms 3', 4 are expanded or compressed, the thread of the two nuts 6 will again be pushed resiliently in radially outward directions by the thread of spindle 9, thereby permitting a rapid major adjustment of the two arms 3', 4'.

In order to facilitate placement of the nut within the appropriate instrument arm, the nut may be inserted into a supporting piece, which supporting piece is in turn inserted into a transverse bore of the arm and then fastened 4 therein, for example by riveting. Thus, in the species illustrated by FIGURES 5 and 6, the resilient nut 6, rather than being inserted directly into the instrument arm, is disposed within an insert 14 which is in turn placed within and riveted to, a recess 15 of the compass arm 16.

It is also possible, in accordance with an additional characteristic of the invention, to insert the nut into a recess formed in the compass arm and opening into one face of said arm transversely to the spindle, said recess being covered by means of a disk imbedded in the arm. In this manner, the manufacture of the nut-receiving recesses within the arms, as well as the mounting of the resilient nuts therein, will be greatly facilitated. Thus, in the species of the present invention shown in FIGURES 9 and 10, the instrument arm 17 is provided with a recess 18 opening into one face of said arm 17. A resilient nut 19, round in case of this species, is inserted into said recess 18 and is then secured in position by a flushrecessed disk 20 appropriately fastened to arm 17. As in the case of the other species described earlier, nut 19 can again be provided with either a preformed thread, or with an unthreaded bore having a diameter smaller than the outer diameter of the spindle 9' so that the spindle will cut its own thread.

In order to insure permanent resiliency of the nut within the area of the spindle thread, the nut is preferably inserted in a metal ring arranged within the arm to avoid any detrimental expansion. Thus, in the species of FIG- URE 11, the resilient nut 19 is inserted into a rigid ring 21, made for example of metal, fastened within arm 17', in the manner described in reference to FIGURES 9 and 10, and provided with through-bores for insertion of spindle 9. The nut 19 again can consist of an appropriate resilient material; and ring 21 tends to assure permanent resiliency of the nut by preventing any detrimental expansion thereof during coarse or fine adjustments of the instrument.

In accordance with another form of the invention, the nut itself can be made of an inflexible material and can be provided with an unthreaded bore, the diameter of which bore is equal to, or larger than, the outer diameter of the spindle; and an insert can then be placed into the nut and pressed against the spindle, which insert consists of a resilient material, preferably a resilient homogeneous substance of the type described previously. When screwed into the insert, the spindle will cut its own counterthreaded so that the nut, and its associated instrument arm, are retained on the spindle. Again, however, the mechanism is adapted to permit relative sliding motion between the nut and spindle upon compression or expansion of the instrument arms, due to the fact that the aforementioned insert will be resiliently distorted by the spindle in radial directions during such manipulaiton of the instrument arms. The aforementioned resilient insert can, as will appear, take various forms. It may consist, for example, of a wedge placed transversely into the nut and protruding into the area of the spindle, the spindle cutting the thread into it.

Thus, as shown in FIGURES 12 and 13, the instrument arm 22 maybe provided with a rigid circular disk 23, made of metal or of synthetic material, positioned for rotation free of play within a recess in arm 22, and covered by a plate 24. Rigid circular disk 23 is provided with a through-bore adapted to receive spindle 9, with the diameter of said spindle being equal to, or smaller than the diameter of the bore. Inserted into the rigid circular disk 23 is a wedge 25 made of an appropriate resilient material; and, as shown in FIGURES 12 and 13, the wedge insert 25 includes a portion protruding into the thread of spindle 9, so that the spindle 9' cuts or resiliently presses a complementary thread into said insert 25 for the purposes already described.

A second wedge can be provided at the other side of the spindle, also placed transversely into the nut and protruding into the area of the spindle. Thus, in the species of FIGURE 14, which is closely related to that of FIG- URES 12 and 13, the disk 23, which corresponds in function to the circular disk 23 of FIGURES 12 and 13, has inserted therein a pair of identical wedges 25' disposed adjacent opposite sides of the spindle 9'. The second wedge 25', thus added in the species of FIGURE 14, likewise protrudes into the area of the thread of spindle 9" in the manner, and for the purposes, already described.

The resilient insert can also consist of a wedge placed into a bore vertically to the spindle and pressed against the spindle by means of a screw. Moreover, the nut can comprise a wedge running transversely through the arm, with a screw member applied and fastened thereto in such manner that it can be serviced from the outside. This arrangement makes it possible to vary the surface pressure if necessary. The resilient insert may also take the form of at least one steel ball which is pressed by spring force into the thread of the spindle which, in the case of this species, should be hardened. In place of a ball, components of any other desired shape can be employed, so long as they are subjected to a spring force. It is also possible to swivel-mount the nut within a recess of the arm by means of a bolt, resulting in great simplicity of the recess design and manufacture.

Thus, in the species illustrated in FIGURES 15 and 16, a rigid member 29, made of metal or synthetic material, is swivel-mounted for pivotal movement on a bolt 28 located within a recess 26 of the instrument arm 27. Member 29 is provided with a bore 40 for insertion of spindle 9, the diameter of the spindle again being equal to, or smaller than the diameter of the bore 40. The member 29 is provided with another bore 41 which extends transverse to the direction of elongation of spindle 9'. A Wedge 30 made of resilient material, is inserted into transverse bore 41, and is pressed against the spindle 9' by a pressure adjustment screw 31.

FIGURES 17 and 18 show a species where a rigid bolt 33, made of metal or synthetic material, is mounted rotatably free of play within arm 32. Bolt 33 is provided with a bore for insertion of spindle 9', the outer diameter of said spindle being equal to, or smaller than, the diameter of the bore. The bolt 33 is provided also with another bore which extends vertically to the spindle 9', and into which is inserted a wedge 30, the wedge being pressed against the spindle 9' by a pressure adjustment screw 31' having its head positioned on an outer face of the arm 32 so as to be readily accessible for pressure adjustment purposes.

In another form of the invention, the arm of the compass or other instrument can be provided with a throughbore extending transversely of the spindle, into which is inserted a pair of wedges extending respectively toward both sides of the spindle. The wedges should each be made of a hard, wear-resistant material; and at least one of these wedges may be provided with a thread, said wedges being pressed against the spindle by means of a resilient bracket which is placed under compression and which embraces the arm. In order to insure sufiicient support, the sides of the bracket may be provided with beveled beads which engage corresponding recesses of the two wedges.

Thus, in the species illustrated in FIGURES 19 to 21, the arm 34 is provided with a through-bore 35 which extends transversely to the spindle 3' and into which are inserted free of play two wedges 36 and 37, made of a hard, wear-resistant material such as superpolyamide, said wedges being pressed against the spindle 9' by a spring bracket 38. The sides of bracket 38 which embrace arm 34 of the compass are provided with beveled beads 39 which engage corresponding recesses in the wedges 36 and 37, as shown in detail by FIGURE 21. The end, or ends of wedges 36 and 37 which extend toward the spindle can be provided with a thread of the type shown by FIGURE 7 or 8.

Having thus described my invention, I claim:

1. A compass comprising a pair of arms movable relative to one another, a threaded rotatable spindle adjustably connecting said arms to one another, the threads of said spindle being relatively rigid, a nut mounted within at least one of said arms in engagement with the threads of said spindle, said nu-t having a thread area adapted to cooperate with the threads on said spindle for adjusting the positions of said arms relative to one another upon rotation of said spindle, the thread area of said nut comprising a homogeneous resilient mate-rial having portions protruding into the relatively rigid threads of said spindle, said resilient material being constructed to yield temporarily in radial directions relative to the thread of said spindle in response to the application of forces along the axial direction of said spindle and to resiliently resume its original protruding condition relative to the rigid threads of said spindle upon removal of said axial forces, whereby said spindle and nut may be slidably moved relative to one another by temporary deformation of said resilient material upon manual manipulation of said arms toward and away from one another thereby to permit major adjustments in the positions of said arms relativeto one another without rotation of said spindle.

2. The compass of claim 1 wherein said nut is inserted into a metal ring disposed within said arm.

3. The compass of claim 1 wherein said nut comprises a rigid material provided with an unthreaded bore, the diameter of said bore being at least equal to the outer diameter of said spindle, said homogeneous resilient material comprising at least one resilient insert disposed within said nut and pressed against said spindle.

4. A compass as claimed in claim 1 wherein said nut comp-rises a resilient synthetic material.

5. The compass of claim 1 wherein said nut is provided with an unthreaded bore comprising said resilient material, the diameter of said bore, when said resilient material is in an unstressed condition, being smaller than the outer diameter of said spindle, whereby the thread area of said nut is formed automatically by resilient deformation of said resilient material upon insertion of said spindle into said bore.

6. The compass of claim 5 wherein said nut is disposed within a relatively rigid supporting member, said supporting member being fastened within said arm.

7. In an instrument having at least first and second members mounted for movement relative to one another, a threaded shaft extending between said members in engagement with portions of both said members whereby the relative positions of said members may be varied by rotation of said shaft, at least one of said members including an insert of resiliently yieldable material engaging said shaft in the thread engagement portion of said one of said members, said insert material temporarily deforming in radial directions automatically in response to the application of axial force to said threaded shaft and returning to its original shape and position relative to said shaft upon removal of said axial forces whereby the relative positions of said members may be varied without rotation of said shaft by slidably moving said member along said shaft to effect a temporary resilient yielding of said insert relative to the threads of said shaft.

8. An instrument comprising a supporting structure, first and second elongated arms attached to said supporting structure, at least one of said arms being pivotal-1y attached to said supporting structure whereby said elongated arms may assume different angular positions relative to one another, at least said first arm having an elastically yieldable member attached thereto at a location spaced from said supporting structure, and a threaded rotatable spindle extending from said second arm into thread engagement with said elastically yieldable member, the threaded area of said spindle being relatively rigid to elastically reposition said yieldable member automatically in radial directions relative to said threaded area of said spindle upon the application of axial forces to said threaded area of said spindle, whereby said arms may be angularly repositioned relative to one another by rotation of said spindle and may also be angularly repositioned relative to one another by applying axial forces along said spindle operating to slidably move said first arm relative to said spindle by causing a temporary elastic yielding of said member relative to the threads of said spindle.

9. A compass comprising a pair of arms movable relative to one another, a threaded rotatable spindle adjustably connecting said arms to one another, a nut mounted Within at least one of said arms in engagement with the threads of said spindle, said nut being inserted into a recess in said arm, said recess opening into one face of said arm and being covered by means of a disk imbedded into said arm, said nut having a thread area adapted to cooperate with the threads on said spindle for adjusting the positions of said arms relative to one another upon rotation of said spindle, the thread area of said nut comprising a resilient material arranged to yield in radial directions relative to the thread of said spindle, whereby said spindle and nut may be slidably moved relative to one another upon manual manipulation of said arms toward and away from one another thereby to permit major adjustments in the positions of said arms relative to one .another Without rotation of said spindle.

10. A compass comprising a pair of arms movable relative to one another, a threaded rotatable spindle adjustably connecting said arms to one another, a nut mounted Within at least one of said arms in engagement with the threads of said spindle, said nut having a thread area adapted to cooperate with the threads on said spindle for adjusting the positions of said arms relative to one another upon rotation of said spindle, the thread area of said nut comprising a resilient material arranged to yield in radial directions relative to the thread of said spindle, whereby said spindle and nut may be slidably moved relative to one another upon manual manipulation of said arms toward and away from one another thereby to permit major adjustments in the positions of said arms relative to one another without rotation of said spindle, said nut comprising a rigid material provided with an unthreaded bore, the diameter of said bore being at least equal to the outer diameter of said spindle, at least one resilient insert disposed within said nut and pressed against said spindle, and an adjustment screw bearing upon said insert for adjusting the pressure of said insert against said spindle.

References Cited by the Examiner UNITED STATES PATENTS 334,764 1/1886 Fay 33-l54 355,430 1/1887 Wright 33l54 2,392,704 1 /1946 Simmons. 2,401,321 6/1946 Schwend 33154 2,552,868 5/1951 Rebitzer 33-154 2,588,780 3/1952 Pappelendam 33l54 2,775,916 1/1957 Baxter et al. 85-32 3,098,304 7/1963 Harris 33-454 FOREIGN PATENTS 722,242 1/ 1955 Great Britain.

LEONARD FORMAN, Primary Examiner.

ISAAC LISANN, Examiner.

W. D. MARTIN, Assistant Examiner.

Claims (1)

1. A COMPASS COMPRISING A PAIR OF ARMS MOVABLE RELATIVE TO ONE ANOTHER, A THREADED ROTATABLE SPINDLE ADJUSTABLY CONNECTING SAID ARMS TO ONE ANOTHER, THE THREADES OF SAID SPINDLE BEING RELATIVELY RIGID, A NUT MOUNTED WITHIN AT LEAST ONE OF SAID ARMS IN ENGAGEMENT WITH THE THREADS OF SAID SPINDLE, SAID NUT HAVING A THREAD AREA ADAPTED TO COOPERATE WITH THE THREADS ON SAID SPINDLE FOR ADJUSTING THE POSITIONS OF SAID ARMS RELATIVE TO ONE ANOTHER UPON ROTATION OF SAID SPINDLE, THE THREAD AREA OF SAID NUT COMPRISING A HOMOGENEOUS RESILIENT MATERIAL HAVING PORTIONS PROTRUDING INTO THE RELATIVELY RIGID THREADS OF SAID SPINDLE, SAID RESILIENT MATERIAL BEING CONSTRUCTED TO YIELD TEMPORARILY IN RADIAL DIRECTIONS RELATIVE TO THE THREAD OF SAID SPINDLE IN RESPONSE TO THE APPLICATION OF FORCES ALONG THE AXIAL DIRECTION OF SAID SPINDLE AND TO RESILIENTLY RESUME ITS ORIGINAL PROTRUDING CONDITION RELATIVE TO THE RIGID THREADS OF SAID SPINDLE UPON REMOVAL OF SAID AXIAL FORCES, WHEREBY SAID SPINDLE AND NUT MAY BE SLIDABLY MOVED RELATIVE TO ONE ANOTHER BY TEMPORARY DEFORMATION OF SAID RESILIENT MATERIAL UPON MANUAL MANIPULATION OF SAID ARMS TOWARD AND AWAY FROM ONE ANOTHER THEREBY TO PERMIT MAJOR ADJUSTMENTS IN THE POSITIONS OF SAID ARMS RELATIVE TO ONE ANOTHER WITHOUT ROTATION OF SAID SPINDLE.

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