US3436498A - Flex-shaft switch - Google Patents

Description

April 1, 1969 s. F. MURRAY ET AL 3,436,498

FLEX-SHAFT SWITCH Filed Feb. l5, 1967 Humm mi I I la INVENTORS STEPHEN F. MURRAY BENJAMINHF CHESTNUT BY im United States Patent O U.S. Cl. 20G- 38 7 Claims ABSTRACT F THE DISCLGSURE A drive shaft has two concentric sections each capable of independent rotation from the other. Programming means are attached to one of the sections, with momentary contact initiating means attached to the other. Means are provided to prevent rotation of one section while the other is rotated.

Within the broad iield of time switch mechanisms there exists a multiplicity of machine control applications wherein a particular time cycle must be faithfully reproduced in response to the command of the machine operator. Examples of such control requirements can be found in a host of commercial, industrial, and domestic devices and appliances. A typical domestic application, for example, is found in the ordinary clothes dryer. In such cases there is a demand for obedient repetition of a particular desired timing program, the initiation of each cycle being ideally executed 'with a minimum degree of manual edort.

The present invention is concerned with a novel switch mechanism and has as one of its objects the provision of such a switch which can be manually pre-set to a desired cycle time, while thereafter permitting initiation and unerring repetition of that pre-programmed cycle through rotation of a single drive shaft.

Another object of the invention is the provision of such a switch wherein the pre-programming means and the initiation means are independently operable olf of a single drive shaft.

Another object of the invention is the provision of such a switch wherein the single drive shaft is divided into two independently rotating, concentric sections held together by a pilot interlock connecting means.

Still another object of the invention is the provision of such a switch wherein the pre-programming means is connected to one of such shaft sections and the initiation means is connected to the other of such shaft segments.

Yet another object of the invention is the provision of such a switch wherein the pre-programming means comprises actuator cams having discrete steps for locking the electrical circuit contacts in the closed position during the programmed cycle.

Another object of the invention is the provision of such a switch wherein the initiating means comprises a momentary contact switching means.

Still another object of the invention is the provision of such a switch wherein the momentary contact switching means comprises an actuator cam having a discrete step for closing an electrical circuit contact.

With the above and other objects in view, which will appear as the description proceeds, this invention resides in a novel switching mechanism substantially as described herein and more particularly deiined by the appended claims.

'For illustrative purposes the invention will be described in connection with the accompanying drawings in which:

FIGURE 1 is atop view of the novel switch with a portion of its cover being removed to show the relationship of its various component parts; and

ICC

FIGURE 2 is a cross section of the drive shaft of the switch with its associated programming means and initiating means.

Generally speaking, the objects of the invention are accomplished by providing a time switching mechanism which can be manually pre-set to a desired cycle time, while thereafter permitting initiation and unerring repetition of the pre-programmed cycle through rotation of a single drive shaft. Accordingly, there is included in the present time switching mechanism a supported drive shaft divided into two concentrically aligned sections coupled by a pilot interlock connecting means such that the sections may be independently rotated, a driving mechanism to provide time driven rotation of programming cams connected to one of the shaft sections, means to prevent the programming cams from rotating past their pre-set position, and an actuator cam connected to the other of the shaft sections and having a discrete step for momentraily closing an electrical circuit contact. Termination of a cycle program occurs when the programming cams deiiect their associated reaction members which releases electrical contacts from their closed position. The drive shaft may thereafter be rotated to index the programming cams for repetition of the same cycle program.

Referring now to the drawings, the time switch mechanism is generally indicated with reference numeral 10. The switch is in general contained within a phenolic plastic housing 11 except for constant speed driving means such as synchronous motor 12 which is positioned outside the housing. To the output shaft of drive motor I12 is attached motor pinion i13 which projects through an aperture in the housing. Motor pinion 13 meshes with drive gear 14 which carries a friction actuated clutch consisting of spring washers 15 and :15a connected to the gear. The gear and clutch assemblyI are connected to drive shaft means 16 which is journalled through an aperture in the housing at the motor end. At the other end of the housing the shaft means 16 is journalled through aperture 17 by retaining rings 18 and 18a which also prevent axial movement of the shaft.

Shaft means l16 is divided into iirst and second concentric sections 16a and 16b which are connected by connecting means 19. Connecting means .19 comprises pilot means .19 and interlock means 19 which cooperatively form a pilot interlock means for connecting the sections such that they can be independently rotated and such that the timer switch can be programmed and the program held in place while the timer is initiated through momentary contact means.

Pilot means 19 comprises an extension 20 journalled in recess 21. As will become apparent, the two shaft sections 16a and I16b are capable, because of the pilot means, of being rotated independently of each other. A suitable knob (not shown) is attached to the end 16C of section 16a of the shaft means for manual rotation thereof.

Interlock means 19" comprises tang means 30 and 40 each connected to a section of shaft means 16, and torsion spring 41. Torsion spring 41 surrounds shaft means 16 and is positioned between the two tang means and is cooperatively engaged with such tang means. The spring, in conjunction with the tang means, serves as a resilient interlock betwen the two shaft sections 16a` and 1-6'b. As will be hereinafter explained, it is this construction which allows the programmed cycle of the time switch mechanism to be pre-set and thereafter permit initiation and unerring repetition of the cycle with the complete opera- |tion being carried out on a single shaft means.

Attached to section 16b of the drive shaft there is shown programming means 22. Programming means 22 comprises at least one actuator cam 23 having a discrete arcuate step 24 for engaging a reaction member `25,

through Wedge shaped contact means 26. Engagement of the contact means with the step 24 causes the reaction member to be deected so as to close electrical contacts 27 and 28. As shown in the drawings there are three such actuator cams each having discrete steps cooperating with corresponding reaction members and electrical contacts. It is to be understood 4that the number of such cams as well as the length of the arcuate steps m-ay be varied in accordance with the desired program. As shown in the drawings, the cams and .their associated steps are programmed for drying cycles of automatic dryers.

As previously noted, atached lto section l16b is tang means 30 for preventing the programming means from rotating past its set programmed position. Tang means 30 is in the shape of a cup having a base 30a and a rim me-ans 30h. Manual rotation of shaft means 16 causes rotation of programming means 22. Continued rotation causes positive programming of the machine cycle through the relationship of the discrete steps 24 and the reaction members 25. When the machine has been programmed, tang means 30 prevents further rotation of the programming means by having rim 30b of the tang means engage tab 31. Tab 31 is formed by bending a cut portion of metal front plate 11a of housing 11. Thus section 16b of shaft means 16 is prevented from further rotation.

Attached to section 16a of shaft means 16 is momentary contact Iinitiating means 32. Initiating means 32 comprises an actuator cam 33 having a discrete arcuate step 34 for engaging reaction member 3S. Continued rotation of shaft means 16 causes the discrete step 34 to engage wedge shaped contact means k36 thus deecting reaction member 35 so as to close electrical contacts 37 and 38, the new position of the cam and the arcuate step being shown by the dotted portions 33 and 34. Again, as previously noted, attached to section 16b of lthe shaft means l16 is tang means 4t) to prevent the momentary contact initiating means from rotating past its initiating setting. Upon closing contacts 37 and 38, tang means 40 is brought to a stop by engaging rim 30b of tang means 30, the new position of tang means 40 being shown by the dotted lines 40. Simultaneously, torsion spring 41 is spread as indicated by the dotted portion 41 so as to build up energy to return tang means 40 to its original position. Thus upon release of the manually operated shaft means y16, arcuate step 34 will return to its original position.

Upon closing contacts 37 and 38, .an electrical circuit to the machine motor `(not shown) is completed and the machine is started. A centrifugal switch associated with such motor is' then actuated which completes an electrical circuit to synchronous motor 12. In the case of an automatic dryer, the pre-programmed drying cycle is then carried out. Upon completion of 4the programmed cycle, the machine motor is shut off, thus breaking the electrical circuit to the synchronous motor 12. The cycle can then be repeated by again programming the machine as previously described. i

Functionally, therefore, this invention provides a time switch mechanism which may be used on a machine or device wherein the device must function in accordance with a pre-programmed cycle. The use of the two-sectioned drive shaft means, having the sections connected by a pilot interlock connecting means, enables the programming means to be set and held in place while the momentary contact is being made because of the ability of the sections to be independently rotated. Further rotation of the shaft means provides for a momentary contact which initiates starting of the machine. The momentary contact is readily achieved through the torsion spring-biasing of the tang means which insures that the actuator cam can be returned to its original position upon release of the sha-ft means.

T-hus there is described a novel time switch mechanism which is able to pre-set a programming cycle, and initiate its operation from a single drive shaft. In addition the switch is simple in construction and therefore more reliable. Thus it will be readily apparent to those skilled in the art that this invention provides a new and useful time switch.

What is claimed is:

1. In a time switch mechanism wherein a programmed cycle can be pre-set to close cooperating electrical circuits and thereafter permit initiation and unerring repetition of the programmed cycle, a rotatable drive shaft means supported by a housing for said switch, said shaft means having two independently rotatable sections, means connecting said sections, with switch programming means carried by one of said sections and momentary contact initiating means carried by the other of said sections whereby said switch can be programmed and initiated through simple rotation of said drive shaft means.

2. In a time switch mechanism wherein a programmed cycle can be pre-set to close cooperating electrical contacts and the mechanism initiated through simple manual rotation of a drive shaft and thereafter permit unerring repetition of the programmed cycle, a manually rotatable drive shaft means supported by a housing for said switch, said shaft means having two independently rotatable sections, pilot interlock means connecting said sections, one of said sections carrying programming means, said other section of said shaft means carrying momentary contact means for initiating said mechanism and a driving mechanism cou-pled to said drive shaft means for imparting time-driven rotation thereto.

3. In a time switch mechanism wherein a programmed cycle can be pre-set to close cooperating electrical contacts and the mechanism initiated through simple manual rotation of a drive shaft and thereafter permit unerring repetition of the programmed cycle, rotatable drive shaft means supported by a housing for said switch, said shaft means being divided into rst and secon-d concentric independently rotatable sections, pilot interlock means connecting said sections, programming means carried by said second section of said shaft means, reaction members responsive to said programming means for locking circuit contact means in contiguity, momentary contact initiating means carried by said. tirst shaft section, a reaction member responsive to said momentary contact means for closing an electrical circuit contact means, and a driving mechanism coupled to said drive shaft means for imparting time-driven rotation thereto.

4. In a time switch mechanism wherein a programmed cycle can be pre-set to close cooperating electrical contacts and the mechanism initiated through simple manual rotation of a drive shaft and thereafter permit unerring repetition of the programmed cycle, a manually rotatable drive shaft means supported by a housing for said switch, said shaft means having two independently rotatable sections, means connecting said sections, said connecting means including pilot means, and interlock means including spring loaded tang means connected to each of said sections, one of said sections carrying programming means, said other section of said shaft means carrying momentary contact initiating means for initiating said mechanism.

5. In a time switch mechanism wherein a programmed cycle can be pre-set to close cooperating electrical contacts and the mechanism initiated through simple rotation of a drive shaft and thereafter permit unerring repetition of the programmed cycle, a manually rotatable drive shaft means supported by a housing for said switch, said shaft means being divided into first and second concentric independently rotatable sections, means connecting said sections, said connecting means including pilot means, and interlock means including spring loaded tang means connected to each of said sections, programming means carried by said second section, reaction members responsive to said programming means for locking circuit Contact means in contiguity, momentary contact initiating means carried by said first shaft section, a reaction member responsive to said momentary contact means for closing an electrical circuit contact means, and a driving mechanism coupled to said drive shaft means for imparting time-driven rotation thereto.

6. In a switch mechanism (a) drive shaft means supported by a housing for said switch mechanism, said drive shaft means'beng divided into rst and second independently rotatable concentric sections,

(.b) means to manually rotate said shaft means,

(c) programming means connected to said rst section and reaction members responsive to said programming means and for locking circuit contact means in contiguity,

(d) momentary contact initiating means connected to said second section and a reaction member responsive to said momentary contact means for closing electrical contact means,

(e) connecting means for connecting said sections, said means including pilot means through which one of said sections can be rotated against the other, and interlock means comprising tang means connected to said rst section having rim means, said rim means being adapted to engage a tab means formed in said housing after said programming has -been set, tang means connected to said second section and being adapted to enga-ge said first tang means after said momentary contact means has engaged its reaction member, and torsion spring means to disengage said momentary contact means from its reaction member, and

(f) a driving mechanism coupled to said drive shaft means for imparting time-driven rotation to said shaft means.

7. In a time switch mechanism:

(a) drive shaft means supported `by a housing for said switch, said drive shaft means being divided into rst and second independently rotatable concentric sections,

v(b) means to manually rotate said shaft means,

(c) at least one actuator cam connected to said second section and having a discrete arcuate step for programming said time switch,

(d) at least one reaction member responsive to said actuator cam, and electrical contacts responsive to said reaction members,

(e) a momentary contact actuator cam connected to said rst section and having a discrete arcuate step, (f) a reaction member responsive to said actuator cam and electrical contacts responsive to said reaction member,

(g) connecting means for connecting said shaft sections, said means including Ipilot means through which one of said sections can be rotated against the other, and interlock means comprising tang means connected to said rst section and having rim means, said rim means being adapted to engage a tab means formed in said housing after said actuator cam has has been set, tang means connected to said second section and being adapted to engage said first tang means after said momentary actuator cam has been set, and a torsion spring surrounding said shaft means and being axially positioned -between said tang means and being cooperatively engaged therewith, and

(h) a driving mechanism coupled to said drive shaft means for imparting time-driven rotation thereto.

References Cited UNITED STATES PATENTS 6/1958 Stolle 20G-38 1l/ 1965 Simmons.

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