US3396612A - Adjustable reciprocatory mechanism - Google Patents

Description

Aug. 13, 196s Filed June 13, 1966 J. LAZAN 3,396,612

ADJUSTABLE RECIPROCATORY MECHANISM 5 Sheets-Sheet l' AT TORNEYS Aug. 13, 1968 B. J. I AzAN ADJUSTABLE REGIPROCATORY MECHANISM 5 Sheets-Shea? 2 Filed June 13, 1966 INVENTOR. BENJAMIN J LAzA/v ATTORNEYS United States Patent O ADJUSTABLE RECIPROCATORY MECHANISM Benjamin J. Lazan, Carmel, Calif., assigner to d.

Lazan, Jeannette W. Lazan, and First National Bank of Minneapolis, as trustees under trust agreement dated Oct. 7, 1965 Filed .lune 13, 1566, Ser. No. 557,066 14 Claims. (Cl. 74 837) ABSTRACT OF THE DISCLOSURE A device for converting rotary to reciprocatory movement, involving a crank journalled in support means a-nd a cooperating pitman, and a drive member connected at one end to the pitman and 'having its other end guided for movements in a predetermined direction by guide means `on the support means. The support means is Irotatable on the `axis of rotation of the crank in directions to vary the extent of reciprocatory movement imparted to the drive member by the pitman.

Several devices, heretofore designed for the same general purpose, utilize a crank or eccentric mounted on a second crank or eccentric and adjustable thereon to vary the extent of resultant crank throw between maximum and minimum. In order to accomplish this result, while the device is running, various rgearing and other complex mechanism is used, such mechanism `being costly to produce, both in time and material.

Au important object of this invention is the provision of a simple and relatively low cost mechanism by means of which the amplitude of reciprocation of a reciprocating member may be quickly and easily varied while the device is running.

Another object of this invention is the provision of an adjustable reciprocatory mechanism having means for increasing or decreasing the maximum amplitude of reciprocatory movement which is produced by the present invention, as well as for varying the power output of the reciprocatory member.

Yet another object of this invention is the provision of a mechanism `as set forth, which is highly efficient in operation at various speeds, and which is rugged in construction and durable in use.

The above, and still further highly important objects and advantages of this invention will become apparent from the lfollowing detailed speciication, appended claims and attached drawings.

Referring to the drawings, in which like reference characters indicate like parts throughout the several views:

FIG. l is a view in top -plan of a preferred embodiment of the invention, some parts being broken away and some parts being shown in section;

FIG. 2 is a view in front elevation, some parts being broken away and some parts being shown in section;

FIG. 3 is a horizontal section taken substantially on the line 3 3 of FIG. 2;

FIG. 4 is a vertical section taken substantially on the line 4 4 of FIG. 2;

FIG. 5 is a view corresponding to FIG. 4, but showin-g a dilferent position of some of the parts;

FIG. 6 is a view in top plan of a modied -form of the invention, some parts being broken away;

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FIG. 7 is a view in side elevation of the modification of FIG. 6, some parts being broken away; and

FIG. 8 is `a horizontal section taken substantially on the line 8 8 of FIG. 7.

In the preferred embodiment of the invention illustrated in FIGS. l-5, a frame structure 1 is shown as comprising a base 2, laterally spaced parallel side Walls 3 and 4 and an intermediate wall 5, extending upwardly from the base 2, and an end or rear wall 6 connecting lthe side and intermediate Walls 3-5. A power driven input shaft 7, which may be assumed to be operatively connected to a drive motor or the like, not shown, extends through an opening 8 in the side wall 4 and terminates therebetween and the intermediate wall 5.

Support means in the nature of a generally U-shaped carrier 9 includes a pair of laterally spaced generally parallel wings 10 and 11 and a transverse connecting portion or bar 12 which rigidly holds the wings 10 and 11 in laterally spaced generally parallel relationship. The support carrier 9 is pivotally mounted between the frame Walls 3 and 5 by a pair of axially aligned shafts 13 and 14 respectively, that are journalled in suitable bearings in the frame walls 3 and 5 respectively in axial alignment with the input shaft 7. The carrier 9 supports crank means in the nature of a crankshaft 15 having an integrally formed eccentric 16 disposed between the wings 10 and 11, the crankshaft 15 being journalled in bearings 17 in the wings 10 and 11, on an -axis in radially spaced parallel relationship to the common axis of the shafts 7, 13 and 14. Olne end portion 18 of the crankshaft 15 extends through an arcuate slot 19 in the intermediate frame Wall 5 and terminates in the space between the frame walls 4 and 5. Means for imparting rotation to the crankshaft 15 and its eccentric 16 comprises a pair of drive elements Ior pulleys 20 and 21 rigidly mounted on the input shaft 7 and crankshaft portion l respectively, and an endless 4drive belt 22 entrained over the pulleys 20 and 21. The arcuate slot 19 extends circumferentially with respect to the common axis of the shafts 7, 13 and 14, for a purpose which will hereinafter become apparent.

A pitma-n 23 is journalled at one end 24 yon the eccentric 16, and at its other end is provided with a transverse shaft 25, the axis of which is parallel to the axis of the crankshaft 15, A pair of laterally spaced parallel guide links 26 and 27 are journalled at one end each to an opposite end portion of the transverse shaft 25, and at their other ends each to one end portion of a different one of a pair of axially aligned stub shafts 2S and 29 respectively, that are parallel to the transverse shaft and each of which is rigidly mounted in a radially extending leg portion 30 and 31 respectively that are integrally -formed with the wings 10 and 11 respectively. The links 26 and 27 are ldisposed substantially normal to the pitman 23, as shown in FIGS. 4 and 5, and guide the transverse shaft 25 and adjacent end of the pitman 23 in a path wherein the axis of the shaft 25 moves through the common axis of the shafts 7, 13 and 14, during rotation of the crankshaft 15 and its eccentric 16.

A pair of laterally spaced parallel rigid drive members or links 32 are journalled at one end to the transverse shaft 25 intermediate the adjacent end `of the pitman 23 and the guide links 26 and 27, and have their opposite ends pivotally secured to the intermediate portion of a lever arm 33 by means of a shaft 34 the axis of which is parallel to the shaft 25, the shaft 34 extending through suitable apertures in the drive links 32 and lever arm 33. The lever arm 33 extends in a generally vertical direction and has its lower end ymounted on a rockshaft 35 that is journalled in a pair of bearing bosses 36 on the base 2, the axis of the shaft 35 being parallel to the axes of the shafts 25 and 34.

For the purpose of the present example, the lever arm 33 is provided with a plurality of longitudinally spaced transverse opening 37 for selective reception of a transverse pin 38 that extends axially through the bifurcated end 39 of a drive link 40 that extends laterally outwardly from the lever arms 33 in a direction generally parallel to the drive links 32.

The carrier wing is formed to provide a toothed gear sector 41 that has meshing engagement with a worm 42 mounted on a shaft 43 that is journalled in a boss or housing 44 integrally formed with or suitably attached to the intermediate wall 5 of the frame structure. Rotation is imparted to the form 42 by means of a handwheel or the like 45 suitably mounted on the opposite end of the shaft 43 to rotate the support carrier 9 between opposite extreme positions shown in FIGS. 4 and 5. A conventional commercially available counter 46 is mounted on the housing 44, and may be assumed to be operatively connected to the worm shaft 43 to indicate the position of the support carrier 9 between its extreme positions of FIGS. 4 and 5. The arcuate elongation of the slot 19 in the intermediate wall 5 permits the crankshaft 15 to be moved in common with the support carrier 9 between its positions of FIGS. 4 and 5.

With reference to FIG. 4, it will be seen that, in the position of the support carrier 9 therein shown, rotation of the crankshaft and its eccentric 16 will impart angular reciprocatory movement to the lever arm 33 between extreme positions indicated by center lines A and B at opposite sides of a neutral position, indicated by a center line C. With the support carrier 9 in the position shown in FIG. 4, the pitman 23 and drive links 32 are in substantial alignment, with the guide links 26 and 27 being substantially at right angles thereto. With this arlrangement, the length of reciprocatory movement imparted to the drive links 32 is substantially equal to the fixed throw of the eccentric 16, resulting in maximum angular reciprocatory movement being imparted to the lever arm 33. As the support carrier 9 is rotated in a counterclockwise direction with respect to FIG. 4, toward its position of FIG. 5, the angular relationship between the pitman 23 and drive links 32, as well as the angular relationship between the guide links 26 and 27 and the t drive links 32, changes, whereby to shorten the reciprocatory stroke of the drive links 32, until as shown in FIG. 5, the pitman 23 is disposed substantially normal to the drive links 32, resulting in zero movement of the drive links 32 in a direction to reciprocate 'the lever arm 33. With reference to FIG. 5, it will be seen that the pitman 23 is substantially parallel to the lever arm 33, and that the axes of the stub shafts 28 and 29 are substantially aligned with that of the shaft 34. Thus, the guide links 26 and 27 and drive links 32 partake of common rocking movements in a generally upward and downward direction responsive to rotation of the eccentric 16. However, the guide links 26 and 27 being pivotally secured to the support carrier 9, effectively prevent reciprocatory movement of the drive links 32 in directions to reciprocate the lever arm 33, may be2 infinitely varied between neutral position, indicated by the central line C.

From the above, it will be appreciated that, by manipulation of the hand wheel 45, reciprocatory movement imparted to the drive links 32 in directions to reciprocate the lever arm 33, may be indefinitely varied between zero and maximum movement as shown in FIGS. 5 and 4 respectively. The support carrier 9 being rotatable on the axis of the input shaft 7, driving engagement between the pulleys and 21 is maintained in all positions of 4 the support carrier 9 without the necessity for idler pulleys or other devices for maintaining tension in the belt 22.

The reciprocating mechanism of this invention may be used to impart reciprocatory movement to any device or mechanism which requires reciprocation. For the purpose of the present example, the mechanism is shown in FIGS. 4 and 5 as being operatively connected to a workpiece or specimen, indicated at 47, that is rmly anchored at one end by suitable means such as a stationary clamp 48. The transfer link 40 is pivotally connected, as indicated at 49, to a conventional clamping bracket that is releasably locked to the other end of the specimen 47, whereby to impart bending movements to the specimen or workpiece 47 to test the fatigue strength of the workpiece or specimen. It will be appreciated that, while the amplitude of reciprocatory movement of the lever arm 33 may be varied between maximum and zero movement, as above described, the amplitude of bending movement applied to the specimen 47 may be further varied by connecting the bifurcated end 39 of the transfer link 40 to the lever arm 33 selectively at others of the openings 37. Obviously, by connecting the transfer link 4t) to the uppermost opening 37, the amplitude of bending movement applied to the specimen 47 Will be increased, although the power applied thereto will be decreased due to dilferent leverage conditions in the lever arm 33; whereas, if the transfer link 40 is connected to the lowermost opening 37, the bending movement applied to the specimen 47 will be considerably lessened, with a resultant greater power applied thereto. It will be appreciated that the location or level of the anchoring bracket 48 may be vertically moved relative to the frame structure 1, so that the transfer link 40 may be maintained in substantially parallel relationship with the drive links 32.

In the modified form of the invention illustrated in FIGS. 6 3, a frame structure 51 yis shown as comprising a base 52, an end wall 53 and laterally spaced side Walls 54 and 55. An input shaft 56 is shown as having mounted thereon a pulley 57 over which is entrained an endless drive belt `58 that runs over a second pulley 59, mounted fast on one end of the crank shaft 60. A support carrier 61 includes a mounting shaft 62 that is journalled in a bearing 63, mounted in the side Wall 55, for pivotal movements on an axis aligned with the axis of the input shaft 56, and is formed to provide a bearing boss 64 that extends through an arcuate slot 64a in the side wall 55, and which journals the crankshaft on an axis parallel to the common axis of the shafts 56 and 62. It will be noted that the support carrier 61 comprises a pair of wings 65 and 66, the former of which comprises the bearing boss 64 and shaft portion 62, and a connecting bar portion 67.

The crankshaft 60 includes an integrally formed crank portion of eccentric 68 on which is journalled one end of a pitman 69 to the other end of which is rigidly connected a shaft 70 disposed in spaced parallel relationship to the crankshaft 60. At opposite sides of the pitman 69, the shaft 70 is provided with sleeve bearings 71 and 72 that are slidably disposed in respective ones of a pair of parallel elongated slots or channels 73 and 74 in the carrier wings `65 and 66 respectively. A portion of the bearing 72 is slidably disposed in a generally vertically elongated slot 75 in the longitudinally central portion of a generally vertically disposed lever arm 76 that is pivotally mounted at its lower end portion, as indicated at 77, to a bearing boss 78 on the base 52 for swinging movements on the horizontal axis parallel to the common axis of the shafts 56 and `62 and the crank shaft 60. The lever arm 76 is provided with a plurality of longitudinally spaced transverse openings 79 for selective reception of a connecting pin or the like 80 that is mounted in the bifurcated end 81 of a transfer link 82 similar to the transfer link 40.

The wing 65 is formed to provide a gear sector 83 that is operatively engaged by a worm 84 that may be assumed to be mounted on a worm shaft, not shown, but contained within a housing l85 and rotated by a handwheel 86. The worm 84, handwheel 86 and parts associated therewith are identical to the parts 42-46 illustrated in FIGS. l-5.

With the parts positioned as shown in FIG. 7, the longitudinal dimension of the parallel slots 73 and 74 are substantially at right angles to the slot 75 in the lever arm 76. In this position of the support carrier 61, maximum amplitude of reciprocatory movement of the lever arm 76 is obtained, the shaft 70 being moved by the pitman 69 in a direction substantially at right angles to the lever larm 76. However, as the support carrier 61 is rotated in a counterclockwise direction with respect to FIG. 7, the angular relationship between the longitudinal dimensions of the slots 73 and 74 and the slot 75 decreases, resulting in a lessening of the extent of reciprocatory movement of the lever arm 76 about the axis of the pivotal mounting 77. When the support carrier 61 is rotated to a point where the longitudinal dimensions of the slots 73 and 74 and the slot 75 are substantially vertical or parallel, reciprocatory movement of the lever arm 76 is reduced to zero movement.

It will be appreciated that in yboth of the forms of the invention illustrated, the amplitude of reciprocatory movement may be varied between maximum and zero while the apparatus is running, once the maximum desired amplitude is established by the selected connection of the transfer link to the lever arm. lt will be further appreciated that, while I have shown and described a commercial embodiment and one modification of my reciprocatory mechanism, that the same is capable of further modification without departure from the spirit and scope of the invention, as defined in the claims.

What is claimed is:

1. Adjustable reciprocatory mechanism comprising:

(a) a frame structure,

(b) support means pivotally mounted in said frame structure,

(c) crank means journalled in the support means on an axis in spaced relationship to the mounting axis of said support means and having a predetermined crank throw,

(d) a pitman journalled at one end to said crank means,

(e) guide means on said support means mounting and guiding the other end of said pitman for reciprocatory movements in a predetermined path reiative to said support means generally radially of said crank means,

(f) a drive member mounted for reciprocatory movements in a predetermined direction relative to said frame structure,

(g) said drive member having means operatively connecting said drive member to said other end of the pitman for angular displacement of one of said drive member and pitman relative to the other thereof,

(h) and means for imparting pivotal movements to said support means relative to said frame structure to vary the angular relationship between said pitman and said drive member, whereby to vary the extent of reciprocatory movement imparted to said drive member in said predetermined direction.

2. The reciprocatory mechanism defined in claim 1 in which said guide means comprises a rigid guide link having one portion pivotally secured to said other end of the pitman and another portion longitudinally spaced from said one portion pivotally connected to said support means, the pivotal connection of said guide link portions to said pitman and support means being disposed on axes parallel to the axis of said crank means.

3. The reciprocatory mechanism defined in claim 2 in which said guide link is angularly displaced from said pitman whereby to be disposed generally normal to said pitman.

4. The reciprocatory mechanism defined in claim 2 in which the pivotal mounting axis of said support means is disposed substantially in the path of travel of the axis of said means pivotally connecting said guide link and pitman.

5. The adjustable reciprocatory mechanism defined in claim 1 in which said support means includes a Wormgear sector concentric with the pivotal mounting axis of said support means, said means for imparting pivotal movements to said support means including said gear sector and a worm journalled in said frame structure and having intermeshing engagement with said gear sector.

6. The adjustable reciprocatory mechanism defined in claim 1, characterized by a lever arm having one end pivotally mounted on said Ifrarne structure and defining a plurality of longitudinally spaced transverse openings, and shaft means extending through one of said openings and providing a pivotal connection between said drive member and said lever arm.

7. The adjustable reciprocatory mechanism defined in ciaim 6 further characterized by a rigid transfer link having means at one end for pivotal connection to said lever arm at a selected one of said transverse openings, and means at its other end for releasably locking said transfer link to a member to be moved thereby.

8. The adjustable reciprocatory mechanism defined in claim 1 in which said frame structure includes a pair of laterally spaced frame members, said support means comprising a pair of laterally spaced wings each disposed adjacent a different one of said frame members, and a cross member rigidly connecting said wings, said wings being piovtally secured to adjacent ones of said frame members on a common axis.

9. The adjustable reciprocatory mechanism defined in claim 8 in which said pitman is journalled on said crank means intermediate said wings, said guide means comprising a pair of rigid guide links each disposed between said pitman and a different one of said wings and each pivotally connected at one end to an opposite side of said pitman at said other end thereof on an axis parallel to said crank means, said guide links being pivotally connected at their other ends to adjacent ones of said wings on a common axis parallel to said crank means axis, said guide links being disposed generally normal to said pitman.

10. The adjustable reciprocatory mechanism defined in claim 8 in which said crank means comprises a crank shaft and an eccentric on said crank shaft, said crank shaft being journalled in said wings, one of said frame members having an arcuate slot therethrough, a portion of said crankshaft extending through said slot and movable longitudinally of said slot responsive to pivotal movements of said support means.

11. The adjustable reciprocatory mechanism defined in claim 8, characterized by means for imp-arting rotation to said crank shaft including a power driven shaft axially aligned with the pivotal mounting of said support means, and interconnected driving elements on said power driven shaft and said crankshaft.

12. The adjustable reciprocatory mechanism defined in claim 1 in which said guide means comprises a guide channel in said support means extending generally radially relative to said crank means, said other end of the pitman having a shaft projecting laterally into said guide channel for movements longitudinally thereof.

13. The adjustable reciprocatory mechanism defined in claim 12 in which said drive member comprises a drive arm pivotally mounted at one end in said frame structure, said means pivotally connecting said drive member to the other end of the pitman including said shaft and a longitudinally extending slot in said drive arm intermediate the ends thereof for reception of a portion of said shaft.

14. The adiustable reciprocatory mechanism defined in claim 13 in which said drive arm includes a plurality of longitudinally spaced transverse openings, characterized by a rigid transfer link having means at one end for pivotal connection to said lever arm at a selected one of said transverse openings, and means at its other end for releasably locking said transfer link to a member to be moved thereby.

References Cited UNITED STATES PATENTS 1,749,879 3/1930 Goddard 74-116 FRED C. MA'ITERN, JR., Primary Examiner.

W. S. RATLIFF, Assistant Examiner.

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