US3872733A

US3872733A - Motion transmitting apparatus

Info

Publication number: US3872733A
Application number: US461364A
Authority: US
Inventors: James C Sanderson
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-04-16
Filing date: 1974-04-16
Publication date: 1975-03-25
Anticipated expiration: 1992-03-25

Abstract

A transmission includes means driving a pulley connected to a plurality of crank arms which in turn each engage an elongated cam slot formed within separate pivotable rock levers. As the pulley is driven the connected crank arms revolve to oscillate the rock levers such that individual connecting rods likewise carried by the rock levers are caused to reciprocate and thereby drive a crank shaft joined to their free ends.

Description

United States Patent 1191 Sanderson Mar. 25, I975 MOTION TRANSMITTING APPARATUS [22] Filed: Apr. 16, 1974 [21] Appl. No.: 461,364

[52] US. Cl. 74/66 [5 I] Int. Cl. Fl6h 21/14 [58] Field of Search 74/66, 65

[56] References Cited UNITED STATES PATENTS 124,829 3/1872 Langdonu... 74/65 1,585,929 5/1926 Loessel 74/65 FOREIGN PATENTS OR APPLICATIONS 102,171 8/1925 Austria 74/66 Primary Examiner-Wesley S. Ratliff, Jr. Attorney, Agent, or Firm-Emory L. Groff, Jr.

[57] ABSTRACT 9 Claims, 5 Drawing Figures .1 1 MOTION TRANSMITTING APPARATUS This invention relates generally to motive translating mechanisms and more particularly to an improved apparatus for transmitting motion by means of a unique arrangement including a plurality of pulleys, crank arms and reciprocating levers.

Transmission devices for conveying power from a driving source to a driven member and which incorporate rotating cranks and reciprocating levers are generally well known. In many such prior devices a noteworthy shortcoming has been the excessive drag or frictional force which has been produced during operation of the apparatus which, coupled with an often erratic motion between certain of the moving components, resulted in a not too acceptable device. By the present arrangement a unique combination of rotating cranks and oscillating or rocking levers is incorporated in combination with a novel floating connection between the crank arms and oscillating levers which has been found to yield a vastly improved operating mechanism.

Accordingly, one of the primary objects of the present invention is to provide an improved motion transmitting apparatus incorporating a plurality of rotating cranks engaging, by a floating connection, with a plurality of rock levers which in turn produce a reciprocating motion in a plurality of connecting rods leading to a driven power shaft.

Another object of the present invention is to provide in a motion transmitting apparatus a floating connection between a rotating drive pin and an oscillating rock lever which includes an elongated cam slot.

Still another object of the present invention is to provide an improved motion transmitting apparatus including a plurality of adjacent sub-assemblies, each of which includes a rotating crank arm engaging, by means of a floating connection, an oscillating rock lever and wherein the crank arms are arcuately out of phase with one another.

With these and other objects in view which will more readily appear as the nature of the invention is better understood, theinvention consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed.

A practical embodiment of the present invention is shown in the accompanying drawing, in which:

FIG. 1 is a side elevation of the motion transmitting apparatus of the present invention.

FIG. 2 is an end elevation of the structure shown in FIG. 1.

FIG. 3 is a top plan view of the structure of FIG. 1.

FIG. 4 is an enlarged partial top plan view taken along the line 4-4 of FIG. 1.

FIG. 5 is a fragmentary side elevation view of the floating connection between the crank arm and rock lever on the reverse side of the invention as viewed in FIG. 1.

Similar reference characters designate corresponding parts throughout the several views of the drawings.

Referring now to the drawing, particularly FIG. 1, the present invention will be seen to include a standard or support frame, generally designated 1, comprising a plurality of uprights 2 joined at their tops by a crossbeam 3 and which serve as a support or mounting means for the motion translating components of the apparatus. At least a pair of the above described standards are provided in a spaced apart manner as shown in FIG. 2 and secured to the top of each cross-beam 3 is a bearing mount 4 having a single longitudinal drive shaft 5 journaled therethrough and extending laterally beyond the outer limits of each of the bearing mounts 4. Keyed to the drive shaft 5 between the two bearing mounts 4 is a large diameter intermediate pulley 6 which is adapted to be rotated by means of a drive belt 7 receiving its motive force from a small drive pulley 8 driven by an electric motor 9. This motor may be mounted upon a support 9 or otherwise secured to a suitable platform extending from the frame 1.

Rigidly attached to the distal portions of the drive shaft 5 are a pair of crank arms It) each of which is of a substantially lesser length than the radius of the pulley 6. The inboard end of each crank arm 10 is securely I affixed to the drive shaft 5 such that the two crank arms will be mounted out of phase with one another and preferably are disposed to define a angle therebetween as shown most clearly in FIG. 1 of the drawing. Carried by the free rotating end portion of each crank arm 10 is a drive pin 11 shown in detail in FIG. 4 of the drawing and which includes a reduced-diameter portion intermediate its ends defining a peripheral groove 12 surrounding the hub 13. The groove 12 of each drive pin is adapted to engage the upper portion of a rock lever, generally designated 14, by means of a specially configured cam slot l5 such that operation of the drive motor 9 will transmit motion by way of the small diameter drive pulley 8 and drive belt 7 to the large diameter intermediate pulley 6 which will be understood to result in a rotary displacement of each of the drive pins 11 which travel, during one revolution of each crank arm 10 within the confines of the cam slot 15, from the upper portion thereof to the lower portion thereof and return. A longitudinal slot 10a in each crank arm permits individual adjustment of the radial positioning of the two drive pins 11.

Each rock lever 14 includes a bar'like element which is pivotally attached to a fixed pivot shaft 16 carried by the cross member 17 forming a part ofthe frame 1. As will be noted, the pivot shaft 16 engages the rock levers 14 at a point adjacent the lowermost portion of the rock lever such that each rock lever is thereby divided into an upper major section 18 and a lower minor section 19. It will thereby follow that upon arcuate displacement of the crank arm 10 from the 3 oclock position as shown in FIG. 1 of the drawing to the diametrically opposed 9 oclock position, a significant oscillation of the upper section 18 of the rock lever will occur which will produce a much smaller oscillation of the adjacent lower minor section 19 of the respective rock lever. This minor oscillation of the lower section 19 is transmitted by means of a connecting rod 20 suitably attached to the bottom of the rock lever as by a pin 21, to a driven crank shaft comprising a power shaft 22 journaled within bearing mounts 23 attached to the platform 24- which may be carried by the standard 1.

Rotary motion is produced in the driven shaft 22 by means of a crank 25 formed at each distal end of the driven shaft 22 and to which the other end of each connecting rod 20 is connected such that reciprocation of the connecting rods 20 will result in rotary motion of the driven shaft 22, it being understood that the two cranks 25-25 at opposite ends of the shaft 22 are likewise offset from one another 90. The rotating motive force delivered to the driven shaft 22 may be utilized to operate any desired device such as by keying a pulley 3 26 to the medial portion of the shaft 22 for driving a belt 27." I

To provide a smooth balanced operation between the various movable components of the present invention it is necessary to incorporate at least a pair of the crank arms disposed out of phase with one another as previously described. Each crank arm 10, rock lever 14,

The formation of the 'cam slot provided in the upper portion of each of the major sections 18 of the rock levers 14 is critical in order to produce the smoothest operation of the present invention. It will be apparent that the longitudinal extent of the slot can be no less than the diameter ofthe arc as described by the outermost periphery of the drive pin hub 13 since the throw of this hub must be accommodated by the slot when in the extreme lower and upper positions present when the hub is at the 6 and 12 oclock locations. Each cam slot 15 includes an upper section 28 which is curved in one direction with respect to the medial area of the slot and a lower section 29 which is generally curved in the opposite direction from the medial portion of the slot. A continuous uninterrupted cam surface or track 30 is provided by the edge of the entire cam slot 15 and will be seen to be formed so that a relatively narrow width is provided in the upper section 28 of the cam slot while a substantially large width is provided in the lower section 29 of each cam slot 15. By this arrangement it will be understood that at all times each lever is slidably engaged on both its faces by the side walls of the groove 12 in the drive pin 11 while on the other hand the periphery of the hub 13 alternately engages one and both sides of each cam surface 30 during each revolution of the pulley 6. The curvature and size of the front and rear cam slots l515 are generally similar yet do differ from one another an amount which has been calculated to provide a smooth efficient operation. The upper section 28 of the rear lever will be understood to include a smaller width for a greater extent of its length than the front lever upper section, as viewed in FIG. 1 while the lower section 29 of the front lever is provided with a larger width for a greater extent of its length than the rear lever lower section.

1. A motion transmitting apparatus including, a drive shaft, a pulley fixed to said drive shaft, power means connected to said pulley to rotate said drive shaft, a pair of crank arms carried by said drive shaft, a pair of rock levers each having a minor. section and a major section with an intermediate pivot point, the free end of each said major section disposed adjacent one said crank arm, each said lever major section provided with an elongated cam slot bounded by a continuous cam track, each said cam slot having an upper and a lower curved section with said lower curved sections defining a substantially greater slot width than said upper curved sections, drive means on each said crank arm disposed through one said slot and engaging said respective lever cam track whereby rotation of said drive shaft causes said crank arm drive means to revolve about said drive shaft while said major and minor lever sections oscillate about said pivot point whereby, said drive means engages juxtaposed portions of said upper cam tracks and alternately but one side of said lower cam tracks at a time as said crank arm drive means rotates and travels within said slot upper and lower curved sections respectively, a connecting rod having one end pivotally attached to each said lever minor sections, a power shaft including a pair of cranks and each said crank joined to the other end of said connecting rods whereby, said oscillation of said lever. minor sections causes said connecting rods to reciprocate and said power shaft to rotate.

2. A motion transmitting apparatus according to claim 1 wherein, said pulley is disposed intermediate said crank arms, said crank arms projecting radially from said drive shaft and normal to the center axis of said drive shaft.

3. A motion transmitting apparatus according to claim 1 wherein, said crank arm drive means includes a drive pin having a reduced diameter hub constantly disposed within said cam slot.

4. A motion transmitting apparatus according to claim 1 wherein, the diameter described by said crank arm is substantially one-half the diameter of said pulley.

5. A motion transmitting apparatus according to claim 1 wherein, said cam slot length is substantially equal to twice the length of said crank arm from said drive shaft to said crank arm drive means.

6. A motion transmitting apparatus according to claim 1 including, a standard provided with two pairs of uprights, each pair joined at their upper portions by a cross-beam, bearing mounts carried by said cross beams, said drive shaft journaled within said bearing mounts and said pulley disposed between said bearing mounts.

7. A motion transmitting apparatus according to claim 1 wherein, the length of said lever minor section relative the length of said lever major section defines a ratio of substantially 1:6.

8. A motion transmitting apparatus according to claim 1 wherein, said connecting rods are disposed in a plane substantially perpendicular to a line extending through said lever pivot point and said drive shaft.

9. A motion transmitting apparatus according to claim 1 wherein, said cranks are disposed upon said power shaft to one another.

Claims

1. A motion transmitting apparatus including, a drive shaft, a pulley fixed to said drive shaft, power means connected to said pulley to rotate said drive shaft, a pair of crank arms carried by said drive shaft, a pair of rock levers each having a minor section and a major section with an intermediate pivot point, the free end of each said major section disposed adjacent one said crank arm, each said lever major section provided with an elongated cam slot bounded by a continuous cam track, each said cam slot having an upper and a lower curved section with said lower curved sections defining a substantially greater slot width than said upper curved sections, drive means on each said crank arm disposed through one said slot and engaging said respective lever cam track whereby rotation of said drive shaft causes said crank arm drive means to revolve about said drive shaft while said major and minor lever sections oscillate about said pivot point whereby, said drive means engages juxtaposed portions of said upper cam tracks and alternately but one side of said lower cam tracks at a time as said crank arm drive means rotates and travels within said slot upper and lower curved sections respectively, a connecting rod having one end pivotally attached to each said lever minor sections, a power shaft including a pair of cranks and each said crank joined to the other end of said connecting rods whereby, said oscillation of said lever minor sections causes said connecting rods to reciprocate and said powEr shaft to rotate.

9. A motion transmitting apparatus according to claim 1 wherein, said cranks are disposed upon said power shaft 90* to one another.