US3116644A

US3116644A - Variable speed belt drive

Info

Publication number: US3116644A
Application number: US279218A
Authority: US
Inventors: Bochan John
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1963-05-09
Filing date: 1963-05-09
Publication date: 1964-01-07
Anticipated expiration: 1981-01-07

Description

Jan. 7, 1964 J. BOCHAN VARIABLE SPEED BELT DRIVE 2 Sheets-Sheet 1 Filed ma 9, 1963 mmvroa JOHN BOCHAN By W F'IQI H us ATTORNEY Jan. 7, 1964 Filed May 9, 1963 J. BOCHAN 3,116,644- VARIABLE SPEED BELT DRIVE 2 Sheets-Sheet 2 O a, A 37 4 37 ,5 31. 22 4 '32 5s 3 es-- 8| F. G 2 INVENTOR.

JOHN BOCHAN BYMPa/M Hxs ATTORNEY United States Patent 3,116,644 VARHABLE SPEED BELT DRIVE John Bochan, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed May 9, 1963, Ser- No. 279,218 Claims. (Cl. 74-23017) This invention relates to belt drives, and more particularly to an improved variable speed belt drive.

It is an object of my invention to provide, in the type of variable speed belt drive where the plates of one sheave are shiftable relative to each other to vary the radius of the sheave at which the belt rotates, improved means for selectively effecting this variation.

In carrying out my invention in one form thereof, I provide a variable speed belt drive in which a first pair of axially aligned sheave plates is rotatably mounted on a base so as to form a generally V-shaped belt-receiving annular groove between them. A second pair of similar sheave plates is also mounted on the base with their axis of rotation removed from the axis of rotation of the first pair, and an endless flexible belt is seated in the grooves of the pairs of sheave plates and links them. At least one sheave plate of one of the pairs is axially movable relative to the other sheave plate of that pair, and is biased toward it, so that the rotational speed relationship of the two pairs of sheave plates may be varied. The first pair of sheave plates is mounted for movement toward and away from the second pair so as to cause movement of the axially movable sheave plate, and biasing means are pro vided to bias the first pair to a first distance from the second pair.

This biasing means may be overcome by speed changing means which, according to my invention, includes a ratchet which is secured to move with the first pair, and is engageable by a pawl mounted on a support member pivotally secured to the second pair eccentrically of the axis thereof. This support member is provided with a guide so that it has reciprocating motion during rotation of the second pair. The pawl is normally biased out of engagement with the ratchet; electrically actuated means are also mounted on the support means, and connected to the pawl so that energization of the electrically actuated means moves the pawl into engagement with the ratchet.

The pawl and ratchet are so formed that the ratchet is moved in a direction opposite to the bias of the biasing means during rotation of the second pair and energization of the electrically actuated means. This has the result that energization of the electrically actuated means causes the speed relationship to be changed from that which prevails when the first pair is in the position to which it is biased by the biasing means; the changed speed relationship will prevail as long as the electrically actuated means remains energized.

The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. My invention itself, however, may best be understood by reference to the following description taken in conjunction with the ac companying drawings.

in the drawings, FlGURE l is a rear elevational view of a typical machine, in this case a combination clothes washing and drying machine, in which my novel variable speed belt drive is incorporated, the view being partly in section and partly broken away to show details; and

FIGURE 2 is a side elevational view of the machine of FIGURE 1, partly in section and with certain surfaces broken away to show details.

Referring now to the figures of the drawings, there is shown a combination clothes Washing and drying machine wherein the operating elements of the machine are included within an outer cabinet structure having a 3,ll6,64 i Patented Jan. 7, 1964 central wrap-around section 1. Section 1 is supported on a base assembly 2 and carries a separate top 3 on which is supported a backsplasher and control panel 4. Access to the interior of the machine is provided by a door 5 formed in section 1, the door being mounted on suitable hinges (not shown) and being opened by any suitable means such as a latch control 6.

The machine has a clothes basket or container 7 mounted for rotation on a generally horizontal axis within an outer enclosing stationary tub structure 8. Basket 7 comprises a cylindrical outer wall 9 provided with a plurality of suitably spaced perforations -10 to allow air and water communication between the interior and the exterior of the basket 7. The rear of the basket is closed by means of a suitable wall or plate 11. The basket also includes a front wall 12 which is formed so as to define an access or loading opening 13 in registry with an opening 14 in Wrap-around section 1 provided for door 5.

The container is rotatably supported by a shaft 15 which is mounted in an elongated bearing 16 supported from rear wall 17 of tub 8. The tub is also provided with an opening 18 aligned with

openings

13 and 14 so that clothes may be placed into and removed from the basket when door 5 is opened. The door seals against a suit able gasket 19 during operation of the machine.

During operation of the machine the basket 7 is driven from an electric motor 20 to which is secured a pulley 21 driving a conventional endless flexible belt 22. Belt 22 has a truncated V-shaped cross section, as best shown in FIGURE 2. Through the improved belt drive of my invention, which Will be described herebelow, the motor 20 effects the rotation of a belt 23 driving a sheave 24 connected to shaft 15 at either high speed or low speed. For instance, a relatively low speed such as 47 rpm. may be provided to the basket for tumbling clothes in the basket during washing and drying operations. However, during the centrifugal spin extraction which is conventional in such machines, the speed of the basket is raised to 30 0 rpm. so as to permit the centrifugal extraction of liquid from clothes in basket 7.

It will be understood that in combination with this structure there are provided the conventional elements of a combination washer-dryer, such as, for instance inlet water valves for providing water for the different washing and rinsing operations, drain means for removal of the water, heating means for effecting heat drying of the clothes after a washing operation has been terminated, and control means for providing proper operation of all these elements in sequence. These elements are not shown since they do not pertain to my inventive concept and may be of any conventional construction, many of which are commercially available at the present time.

The general structure of the variable speed drive will now be described. It has been stated that pulley 21 drives the belt 22. Belt 22, in turn, drives an adjustable sheave assembly 25. The adjustable assembly includes a shaft 26 to which are rigidly secured two

sheave plates

27 and 28. An intermediate sheave plate 29 is keyed on shaft 26 so as to be movable along the shaft 26 to varying distances from

sheave plates

27 and 28. It will be observed that sheave plate 27 has a sloping surface 30 which, in cooperation with sloping surface 31 on movable sheave plate 29, forms a generally V-shaped groove of adjustable width. Similarly, on its other side, movable sheave Plate 29 is provided with a sloping surface 33 which cooperates with sloping surface 34 of rigidly secured sheave plate 23 to form a second V-shaped groove 35 of adjustable width. Since belt 22 has a predetermined width, it can be seen that movement of sheave plate 29 relative to sheave plate 27 will cause the belt 24 to seat in groove 32 at a distance from the center of shaft 26 which is 3 determined by the distance of sheave plate 29 from sheave plate 27.

The linear speed of belt 22 is constant, assuming the speed of motor 29 to be constant, and therefore the rotational speed of the adjustable sheave assembly 25 is dependent on the effective sheave radius provided by the cooperation of

sheave plates

27 and 29, i.e., the distance at which belt 22 is seated. When the

sheave plates

27 and 29 are in the position shown in the figures, sheave assembly 25 is rotating at a relatively low speed. If sheave plate 29 is moved to the left, as viewed in FIG- URE 2, away from sheave plate 27, then belt 22 will move in radially toward shaft 25 as groove 32 widens, and will cause a greater rotational speed of the sheave assembly 25 for a given rotational speed of pulley 21 by motor 29.

A second endless flexible belt 36, also having a truncated V-shaped cross section, is driven in groove by the sheave formed by the cooperation of

sheave plates

29 and 28. When adjustable sheave plate 29 is in the position shown so that groove 36 is quite wide, belt 36 has to move in radially toward shaft 26 a substantial amount before it seats on the

surfaces

33 and 34 of

sheave plate

29 and 28 respectively. This means that for a given rotational speed of the adjustable sheave assembly (as imparted to it by belt 22), belt 36 will be traveling at a relatively low rate of linear speed. If sheave plate 29 is moved to the left so that belt 36 is forced outwardly in groove 35, then for a given rotational speed of the sheave assembly a relatively high linear speed of belt 36 is provided.

Thus, by controlling the position of sheave plate 2"), an infinite variety of speeds between the two limits of position of sheave plate 29 may be provided. The arrangement shown in FIGURE 2 provides the lowest output speed to belt 36 since belt 22 is causing the lowest rate of rotation of sheave assembly 25 and rotation of the sheave assembly 25 is causing the lowest linear speed of belt 36. The highest rate of speed will be provided if sheave plate 29 is moved as far as possible to the left in FIGURE 2, in which case belt 22 moves inwardly as far as possible to provide the highest rotational speed of the assembly 25 for a given linear speed of belt 22, and the output linear speed of the belt 36 is the highest possible for a given rotational speed of assembly 25. It will be observed, in addition, that belts 22 and 36 each exert a biasing force on sheave plate 29, each belt tending to move the plate 29 into engagement with the other belt.

Belt 36 passes over a sheave 37 which forms part of a unitary assembly with a sheave 38 which drives belt 23. It will be understood that the sheave 37 is formed of two

sheave plates

37a and 37b providing a V-shaped groove 37c between them in the same manner as described in connection with the adjustable sheave assembly 25 except for the fact that the plates of sheave 37 are not adjustable. The belt 23 driven by sheave 3% drives sheave 24 and, as previously described, this sheave is rigidly secured to the end of shaft 15 so as to rotate basket 7.

Returning now to the adjustable sheave assembly 25, and with particular reference to FIGURE 1, it will be observed that the assembly is mounted on a mounting structure which includes a V-shaped arm assembly 39 (FIGURE 2) pivotally secured on a pin 40 within a bracket 41 secured to base 2 of the machine. A spring 42 has one end 43 secured to the machine base and has its other end 44 secured to arm 29 so as to bias the assembly 25 to the left, as viewed in FIGURE 1.

The assembly of

sheaves

37 and 38 is mounted on a linkage assembly 45 pivotally mounted on a pin 46 mounted within a bracket 47 secured to base 2. The linkage arrangement includes two

arms

48 and 4% which are pivotally secured together by a pin 50. A pin 51 near the top of arm 49 provides the axis of rotation for

sheaves

37 and 38. A spring 52, secured at one end 53 to base 2 of the machine, is secured at its other end 54 to the assembly of

sheaves

37 and 33 so as to bias them downwardly and to the right (as viewed in FIGURE 1) in order to effect a belt tensioning function for

belts

36 and 23.

As part of my improved speed changing arrangement for the belt drive system described, I provide a rod-like support member 55 which has one end 56 secured in pivotal, or rotatable, relation on the assembly of

sheaves

37 and 38 eccentrically to the axis thereof. A support, or guide, 57 may be secured on the rear Wall E7 of tub 8 so as to support the other end 58 of rod 55. As a result, the rod will have a primarily reciprocating motion when there is rotation of the assembly of

sheaves

37 and 38 in the same manner that a piston rod is reciprocated by the rotation of a crankshaft in an automobile.

Pivotally secured on a pin 59 extending from rod 55 is a pawl member 60. Pawl 60 is normally biased by a spring 61 secured to end 62 of the pawl and to the rod 55 so as to be out of engagement with a ratchet 63 formed as part of the adjustable sheave assembly 25. An electrical actuating assembly, is provided which, in the embodiment shown, comprises a solenoid assembly 64 with a plunger 65 which is drawn into the solenoid assembly, that is, to the left as shown in FIGURE 1, when the solenoid is energized. When this occurs, the solenoid overcomes the action of spring 61 and causes pawl 60 to be pivoted about pin 5 into engagement with ratchet 63. It will be observed that the teeth of ratchet 63 are so formed that the right side of each tooth is sloped so as to permit the pawl to slide over the tooth, while the left side is substantially vertical so as to retain the ratchet when it bears against that surface.

When the solenoid 64 is not energized, pawl 65 is out of engagement with ratchet 63 and consequently the spring 42 is effective to maintain the adjustable sheave assembly 25 in the position shown, in a position toward the left as viewed in FIGURE 1 so as to provide a minimum output speed to the basket as previously described.

When it is described to increase the speed of the basket, solenoid 64 is energized. This pivots pawl 60 down into engagement with the teeth of ratchet 53. Upon each movement of rod 55 to the right, as a result of its eccentric mounting on the assembly of

sheaves

37 and 38, pawl 6t} will pull the ratchet 63 to the right a small amount at a speed faster than that at which spring 42 is capable of pulling ratchet 63 to the left. As the rod reciprocates back to the left because of the continued rotation of the assembly of

sheaves

37 and 38 the pawl will slide up over the slanted right hand surface of a tooth of ratchet 63 so as to be in position to pull the adjustable sheave assembly 25 a little farther again upon the next reciprocating movement to the right of the rod 55. Because the spring 42 pulls the ratchet quite slowly, the ratchet is not moved back to the left far enough, when the pawl is sliding over a tooth, to impede this movement of the assembly to the right. In this way, after a number of rotations of the assembly of

sheaves

37 and 38, the engagement of pawl 60 with ratchet 63 will have caused the pawl to pull the ratchet, and therefore the entire assembly 25, a substantial distance to the right as viewed in FIGURE 1. As explained, this has the dual effect of increasing the speed transmitted from motor 20 to assembly 25, and from assembly 25 to the assembly of

sheaves

37 and 38.

Of course, as soon as it is desired to return to tumble, it is merely necessary to de-energize the solenoid, at which point the spring 51 will move pawl 60 out of engagement with the ratchet and the spring 42 will pull the assembly back to the left to lower the output speed of the system. It will be seen from the foregoing that my invention provides a novel and simple means of achieving the speed variations desired in a variable speed belt drive. Among other advantages, a very small inexpensive solenoid may be used.

While in accordance with the patent statutes I have described what at present is considered to be the preferred embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and I therefore aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A variable speed belt drive comprising:

(a) a base;

(b) a first pair of axially aligned sheave plates rotatably mounted on said base and forming a generally V- shaped annular groove between them;

(0) a second pair of axially aligned sheave plates rotaably mounted on said base with their axis of rotation removed from the axis of rotation of said first pair and forming a generally V-shaped annular groove between them;

(d) an endless flexible belt seated in said grooves and linking said two pairs;

(2) at least one of said sheave plates of one of said pairs being axially movable relative to the other sheave plate of said pair and biased theretoward thereby to vary the speed relationship of said pairs;

(f) mounting means positioning said first pair for movement toward and away from said second pair so as to cause movement of said axially movable sheave plate;

(g) first biasing means connected to said mounting means to bias said first pair to a first distance from said second pair;

(11) and speed changing means for overcoming said first biasing means comprising;

(i) a ratchet secured on said mounting means, (ii) a support member pivotally secured to said second pair eccentrically of the axis thereof, (iii) a guide supporting said support member for reciprocating motion,

(iv) a pawl movably mounted on said support member and engageable with said ratchet,

(v) second biasing means biasing said pawl out of engagement with said ratchet,

(vi) electrically actuated means mounted on said support means and connected to said pawl, said electrically actuated means being arranged so that when energized said electrically actuated means moves said pawl into engagement with said ratchet,

(vii) said pawl and said ratchet being formed to move said ratchet in a direction away from the bias of said first biasing means during rotation of said second pair and energ-ization of said electrically actuated means.

2. The apparatus defined in claim 1 wherein said two pairs of sheave plates have their axes parallel to each other, and said electrically actuated means is a solenoid.

3. The apparatus defined in claim 1 wherein said first biasing means comprises a spring connected between said mounting means and said base so as to bias said first pair away from said second pair, said ratchet and pawl being formed to cooperate to pull said first pair toward said second pair against the action of said spring.

4. The apparatus defined in claim 1 wherein said pawl is pivotally mounted on said support member so as to be pivotable between a position in which it engages said ratchet and a position in which it is disengaged from said ratchet.

5. The apparatus defined in claim 1 wherein said first pair includes said axially movable sheave plate.

Schmied Sept. 3, 1946 Buss Dec. 18, 1962

Claims

1. A VARIABLE SPEED BELT DRIVE COMPRISING: (A) A BASE; (B) A FIRST PAIR OF AXIALLY ALIGNED SHEAVE PLATES ROTATABLY MOUNTED ON SAID BASE AND FORMING A GENERALLY VSHAPED ANNULAR GROOVE BETWEEN THEM; (C) A SECOND PAIR OF AXIALLY ALIGNED SHEAVE PLATES ROTAABLY MOUNTED ON SAID BASE WITH THEIR AXIS OF ROTATION REMOVED FROM THE AXIS OF ROTATION OF SAID FIRST PAIR AND FORMING A GENERALLY V-SHAPED ANNULAR GROOVED BETWEEN THEM; (D) AN ENDLESS FLEXIBLE BELT SEATED IN SAID GROOVES AND LINKING SAID TWO PAIRS; (E) AT LEAST ONE OF SAID SHEAVE PLATES ON ONE OF SAID PAIRS BEING AXIALLY MOVABLE RELATIVE TO THE OTHER SHEAVE PLATE OF SAID PAIR AND BIASED THERETOWARD THEREBY TO VARY THE SPEED RELATIONSHIP OF SAID PAIRS; (F) MOUNTING MEANS POSITIONING SAID FIRST PAIR FOR MOVEMENTS TOWARD AND AWAY FROM AXIALLY MOVABLE SHEAVE PLATE; (G) FIRST BIASING MEANS CONNECTED TO SAID MOUNTING MEANS TO BIAS SAID FIRST PAIR TO A FIRST DISTANCE FROM SAID SECOND PAIR; (H) AND SPEED CHANGING MEANS FOR OVERCOMING SAID FIRST BIASING MEANS COMPRISING; (I) A RATCHET SECURED ON SAID MOUNTING MEANS; (II) A SUPPORT MEMBER PIVOTALLY SECURED TO SAID SECOND PAIR ECCENTRICALLY OF THE AXIS THEREOF; (III) A GUIDE SUPPORTING SAID SUPPORT MEMBER FOR RECIPROCATING MOTION, (IV) A PAWL MOVABLY MOUNTED ON SAID SUPPORT MEMBER AND ENGAGEABLE WITH SAID RATCHET, (V) SECOND BIASING MEANS BIASING SAID PAWL OUT OF ENGAGEMENT WITH SAID RATCHET, (VI) ELECTRICITY ACTURATED MEANS MOUNTED ON SAID SUPPORT MEANS AND CONNECTED TO SAID PAWL, SAID ELECTRICALLY ACTUATED MEANS BEING ARRANGED SO THAT WHEN ENERGIZED SAID ELECTRICALLY ACTUATED MEANS MOVES SAID PAWL INTO ENGAGEMENT WITH SAID RATCHET, (VII) SAID PAWL AND SAID RATCHET BEING FORMED TO MOVED SAID RATCHET IN A DIRECTORY AWAY FROM THE BIAS OF SAID FIRST BIASING MEANS DURING ROTATION OF SAID SECOND PAIR AND ENERGIZATION OF SAID ELECTRICITY ACUTATED MEANS.