US1263042A - Machine element. - Google Patents

Description

I E. H. CURTIS,-Jn. MACHINE ELEMENT. APPLICATION FILED MAR. 6. 1911.

Patented Apr. 16,1918.

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MACHINE ELEMENT.

APPLICATION FILED MAR. 6. I917.

1,263,042. Patented Apr.16,1918.

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Ar W EDMA H. means, .13.. OF nonwoon, .OI-IIO, ASSIGNOR To THE NIVISON-WEISKOPF COMPANY, OF READING, OHIO, A CORPORATION or 01-110.

MACHINE ELEMENT.

v Specification of Letters Patent.

Patented Apr. 16, refs.

Application filed March 6, 1917. Serial No. 152,462.

To all whom it may concern I Be it known that I, EDMA' H. CURTIS, Jr, a citizen of the United States, and a'resident of N orwood, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Machine Elements, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification. I

It frequently happens that a part or member, which is to be operated by a cam on'a power shaft, is insuch close proximity to the power shaft that only a short leverage is possible, and if the work to be performed by such part or member is heavy, 'considerable power must be applied to the driving shaft which, when the usual form of cam is employed, must rotate slowly; The invention described herein hasfor its object a construction whereby the efliciency of a large cam driven at a high speed can be had without increasing the distance between the driving and the driven parts. The invention is hereinafter more fully described and claimed.

In the drawings, I

Figure 1 is a view partly in section and partly in elevation of a machine of the type shown and described in Letters Patent No. 1,007,156, dated October 21,- 1911, embodying my improvement. 1

Figs. 2 and 3 are side and edge elevations showing portions of my improved device on an enlarged scale. 7

Fig. 4; is aside elevation of another form of my invention. I

In the machine shown in Fig.1, it is desired to transmit motion from the power shaft 1 to one or more shafts as 2 or 3. One or more sprocket wheels are keyed on the driving shaft and around these wheels are placed endless chains 5 and 6, which also pass partially around drums 7 and 8 loosely mounted on the shafts 2 and 3. These shafts are provided with radially projecting arms 9 on oppositesides of the drums, the number of such arms being dependent upon the angular movement (6. g. 180, 120 or 90 clegrees) to be imparted to the shafts 2 and 3. The extent to which the drums are encircled by the chains will also be dependent on the required angular movement of the shafts 2 and 3.- The sprocket chains are provided with laterally projecting pins 10 adapted to engage the arms 9 as the chains pass around the shafts 2 audit, and thereby impart the desired angular movement to the shafts. The number of projecting pins on thechains is dependent upon the desiredfrequency of movement of the driven shafts during a complete traverse of the chains. It will be understood that such frequency of movement'of the shafts'is also dependent on the peripheral length of the'chain. The

same frequency can be had with a short chain having one pin'or a chain of double the length but having-two equally spaced pins. 4 I

As the chains can be arranged arounda plurality of guide pulleys 11, any desired length of chain canbe employed, thus permitting a large increase in the rate of rota tion of the driving shaft 1 withoutincreasjing the periodicity of movements of the shafts 2 and 3. And further the movement described herein permits of the transmission of power around parts of a machine lying between the power and driving shafts.

In order to prevent accidental movements of the shafts 2 and 3, provisionis made for locking the same aftereachn'iovement. A suitable construction for this purpose consists of curved fingers 12 loosely 'mounted on shafts or pins 13' (which in this case carries one of the guide pulleys) and adapt- In order that said tooth may not engagea following arm until the movement has been completed, the arms are provided withrollers 18 which will engage thecam'surfac'esfl and holdv the fingers out of the path of movement ofthe arms until the latter have completed their movement and a notch 16 is in position to receive a tooth.

In the modification shown in Fig. 1,-;th'e power shaft 1is shown as' driving a shaft 20 situated alongside of it. The'sha'ft has a sprocketwheel controlling an endlesschain 5 which passes around. a drum 8 on the shaft 2, which drum hasproj'ectiri'g arm's 9,' all as in the above description of the main exmplification of'the invention illustrated.

ed to be'so shifted by a'sprin'g 14- that teeth i it so There is afinger 12, as abovefwhich is":

mounted on a pin 21. A spring 22 mounted under a bracket arm 23 and operating ona pin 24 serves to pull down on the arm'25 which is connected "to-the finger'member.

The spring by pulling on the arm-thereby holds the tooth 15 on the finger in the notch 16-- in one of the arms 9 on theshaft drum.

The position of thefingers is such that it has not required that any particular cam surface, as at 17- above, need be provided, as the pins 10on the chain merely contact with the-extension 26 on'the finger member, The rollers 18 on-the arms 9 willalso contact with this extension in-the= same manner as in'the firstexample. It will be readily understood that in case itis desired to-varythe rate of-rotationof the-powershaft relative to the parts to be driven thereby, the length of the chains can be-varied by-inserting or removing links. Onlytheportion of-the chain passing from the driven to the driving-shaft is in tension andthe portion of the chain-passing from the driving tothe drivenshaft'may hang loosely, unless it becomes necessary to guide it around some other part of the machine. The employment of endless chains to transmit motion fronrone shaft to another isquite commoninthearts, but in all such cases the relation of the driving to the driven shaft issuch-thatboth are rotated simul taneously, and the extent ofangular movement of the driven shaft and the periodicity ofsuchangular movement is in no way dependenton; the length'of the sprocket chain. 7 It is also a known practice to impart intermittent rotation-to-a'star'wheel by means of bringing into engagement with its teeth a finger, said finger located fixedly on a driven elementor on achainor belt 'operated; by the driven elements In these casesthe chain does not pass around i in star wheel, :however,'---and it is readily appreciatedthat in such a mechanical-device as that :last .mentioned,---there has tobe muchspecial construction, chain or belt tensioning and the like. So far as I- amaware, it is entirely novel to transmitintermittent rotary motion from; 7 one element to another by means of an endless flexible member passing around each ofthem, H v

j Having thus described, my invention, what I claim as new and desire to secure by-Leters Patent, is

= a-mechanism ioflobtaining intersprocket chain of a length substantially greater than twice the distance between the axes of said shafts-and. in'constant engagement with i-the driving-shaft, and partially encircling the other shaft, and meansfor causingthe sprocket chain to intermittently engage the shaft to be driven and impart a partial rotation thereto.

2. In a mechanism for transmitting rotary motion, the combination of a driving shaft, a sprocket Wheel thereon, a. shaft to be driven, an'endlesssprocketchain of a length substantially greater than twice the distance between theaxes ofsaid shafts and in constant engagement with the-driving shaft, guiding means for the chain adapted to cause the chain'to move partially around the-shaft to be driven,=and radial arms on the shaft to'loe driven to engagetheschain while moving around the shaft.

3. In a mechanismfor transmitting rotary motion, the combination of a driving shaft, asprocket wheel thereon, a shaft to be driven, an endless chain of a length substantially greater than twice the distance between the said shafts and'in constant engagement with the driving shaft, guiding means for the chain adapted to cause the chain to; move partially. around the shaft to be driven, and radial arms on the: shaft to bedriven adapted to vengage the. chain while -moving around said shaft,'and said arms adapted toreleasethe shaft upon-partial movement thereof.

.4.-In a mechanism for obtaining intermittent rotary motion from Y continuous rotary motion by -means of a flexible conn'ection, the combination with a continuous rotatingelement, and an element to'be rotated thereby intermittently, of an endlessiflexible member passing around and driven-by the continuous :rotating element, said flexible element partially encircling the element to be driven, and means on the flexible element and the element to be; driven to intermittently engage for transmittingv such intermittent rotarymotion. -5. Ina mechanism for transmitting rotary motion, in combination with-a driven rotat .ing element,fand an elementto-;be.-rotated thereby intermittently,- an endless flexible memberpassing around and driven by=the driven rotatingelement, idler meanson the element to be rotated intermittently to per-Z mit said flexible element. 'to pass rpartially around said element without actuating it, and meansoperatively connected to said eleom'ent; adapted to-rbe. intermittently engaged bysaid: flexible element for; imparting such intermittent rotary. motion to the-:elementto be rotated.

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