US3745289A

US3745289A - Actuator for a limit switch construction or the like

Info

Publication number: US3745289A
Application number: US00249536A
Authority: US
Inventors: G Hipple
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1972-05-02
Filing date: 1972-05-02
Publication date: 1973-07-10
Anticipated expiration: 1990-07-10

Abstract

An actuator for a limit switch construction or the like having a rotatable actuating shaft and a rocker arm carried thereby and having an opening passing therethrough and telescopically receiving the shaft therethrough. A wedge is carried by the arm and is wedged between the shaft and the arm at the opening to secure the shaft and the arm together. A pin is carried by the arm to orient the wedge to its wedging position for the shaft even when the arm is unattached from the shaft. All of the means for securing the shaft to the arm are entirely embedded within the arm so as not to project externally therefrom.

Description

lnventor: George M. Hipple, Jackson Township, Ohio [73] Assignee: Robertshaw Controls Company,

Richmond, Va.

[22] Filed: May 2, 1972 [21] Appl. No.: 249,536

[52] US. Cl. 200/172 A, 200/47, 287/52.08, 287/189.36 R [51 Int. Cl. Fl6c 3/00 [58] Field of Search 200/47, 172 A, 153 T; 74/567, 568; 287/189.36 R, 52.08, 53 TX [56] 1 References Cited UNITED STATES PATENTS 2,758,675 8/1956 Callaway 200/47 X 3,255,641 6/1966 Russell 287/52.08 X 3,237,976 3/1966 Campoli.... 287/52.08 2/1923 Mason 287/52.08 UX Umted States Patent 1 11 3,745,289 ippi July 10, 1973 [54] ACTUATOR FOR A LIMIT SWITCH 3,467,416 9/1969 Gourlay 287/l89.36 R CONSTRUCTION OR T LIKE 3,463,523 8/1969 Vasas 287/189.36 R

Primary Examiner-Robert K. Schaefer Assistant ExaminerWilliam J. Smith Attorney-Auzville Jackson, Jr., James T. Candor et a1.

[5 7] ABSTRACT An actuator for a limit switch construction or the like having a rotatable actuating shaft and a rocker arrn carried thereby and having an opening passing therethrough and telescopically receiving the shaft therethrough. A wedge is carried by the arm and is wedged between the shaft and the arm at the opening to secure the shaft and the arm together. A pin is carried by the arm to orient the wedge to its wedging position for the shaft even when the arm is unattached from the shaft. All of the means for securing the shaft to the arm are entirely embedded within the arm so as not to project externally therefrom.

14 Claims, 4 Drawing Figures Patented July ACTUATOR FOR A LIMIT SWITCH CONSTRUCTION OR THE LIKE This invention relates to an improved actuator for a limit switch construction or the like and in particular to the means for securing the rocker arm of the actuator to the rotatable actuating shaft thereof.

It is well known that actuators for limit switch constructions and the like have been provided wherein a rocker arm is secured to a rotatable actuating shaft of the actuator by means that will permit the rocker arm to be adjusted to the desired rotational and/or axial position on the shaft and thereafter be secured to the shaft in such a manner that the same will thereafter cause the shaft to move in unison therewith.

However, it has been found according to the teachings of this invention, that the prior known securing means are so constructed and arranged that the same tend to interfere with thepart that operates the arm when the arm is rotated through a relatively large arc, such as 90 degrees or the like, because such prior known securing means normally extends or projects externally of the arm structure.

Accordingly, it is a feature of this invention to provide an improved means for securing the rocker arm to the actuating shaft of an-actuator for a limit-switch construction or the like wherein all of the parts for securing the arm to the shaft are fully embedded within the arm so as not to project externally thereof.

,In particular, one embodiment of this invention provides an actuator for a limit switch construction or the like having a rotatable actuating shaft and a rocker arm carried thereby and having an opening passing therethrough and telescopically receiving the shaft therethrough. A wedge is carried by the arm and is moved by means into wedging relation between the shaft and the arm at the opening to secure the shaft and the arm together. Means are carried by the arm to orient the wedge to a wedging position for the shaft even when the arm is unattached from the shaft. All of the securing means for securing the shaft and rocker arm together are entirely embedded within the rocker arm so as not to project externally therefrom.

Accordingly, it is an object of this invention to provide an improved actuator for a limit switch construction or the like, the actuator having one or more of the novel features of this invention as set forth above or hereinafter shown or described.

Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIG. 1 is a perspective view of the improved actuator of this invention mounted to a limit switch construction or the like.

FIG. 2 is an enlarged fragmentary side view ofthe rocker arm of the actuator of FIG. 1.

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 2.

FIG. 4 is a broken away exploded perspective view of the rocker arm parts illustrated in FIGS. 2 and 3.

While the various features of this invention are hereinafter described and illustrated as being particularly adapted to provide an acutator for a limit switch construction, it is to be understood that the various fea tures of this invention can be utilized singly or in any combination thereof to provide an actuator for other devices as desired.

Therefore, this invention is not to be limited to only the embodiment illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIG. 1, the improved actuator of this invention is generally indicated by the reference numeral 10 and comprises a housing means 11 detachably secured to a larger housing means 12 by a plurality of fastening members 13, the housing means 12 containing an electrical switch therein (not shown) and thereby comprising a limit switch construction.

The actuator 10 rotatably carries an actuator shaft 14 that projects outwardly from the same and carries a rocker arm 15 secured thereto in a manner hereinafter set forth so that movement of the arm 15 causes like movement of the shaft 14 so that if the shaft 14 is moved or rotated in a certain direction and a certain amount, the actuator shaft 14 will cause the electrical switch within the housing 12 to change its operative condition, such as opening or closing an electrical circuit as the case may be.

Because such actuation of a limit switch construction by rotation of the actuating shaft 14 is well known in the art, and such cooperation between the shaft 14 and the electrical switch within the housing 12 does not form a part of this invention, further description thereof is unnecessary.

However, it can be seen that the rocker arm 15 carries a roller 16 on the outer end 17 thereof whereby a moving part of an apparatus normally is adapted to engage against the roller 16 to cause rocking movement of the rocker arm 15 and, thus, rotational movement of the actuating shaft 14. In this manner if the arm 15 is moved by such moving part in the proper direction and with the proper distance of movement thereof,

the limit switch construction 12 will then be operated, such as to cause such moving part to reverse its direction of movement, and permit the shaft 14 to move back to the null or home position, thereof illustrated in FIG. I.

The rocker arm 15 is so constructed and arranged that the same is adapted to be adjusted rotationally and/or axially on the shaft 14 so as to position the roller 16 in the desired position relative to the housing -12 for engagement by the moving part or the like of the apparatus untilizing the limit switch construction 12. Such securing means for permitting SUJCI'I adjustment of the rocker arm 15 relative to the shaft 14 as well as securement of the rocker arm 15 to the shaft 14 forms the teachings of this invention now to be described.

As illustrated in FIGS. 3 and 4, the rocker arm 15 has an opening 18 passing therethrough and being of a circular cross-sectional configuration to complement the circular cross-sectional configuration of the shaft 14 which is adapted to be telescopically received through the opening 18 of the rocker arm 15 in the manner il lustratedinFIGS. 1, 3 and 4. A bore 19 is formed in the rocker arm 15 transverse to the opening 18 and in offset relation thereto while still intersecting with the opening 18. A wedge 20 is disposed within the bore 19 and is originally of cylindrical configuration but is cut away to define a cam or wedgeing surface 21 that will be adapted to bear against the shaft 14 in themanner illustrated in FIG. 3 to wedge between the arm 15 at the bore 18 and the shaft 14 to cause the shaft 14 to wedge in tight relation against the arm 15 and thereby be firmly secured to the arm 15 so that movement therebetween cannot take place unless the wedge 20 is moved to an unwedging position thereof.

In order to move the wedge 20 in its wedging relation with the shaft 14, a portion 22 of the bore 19 is internally threaded to threadedly recive an externally threaded set screw 23 which when threaded in the proper direction in the threaded portion 22 of the bore 19 will abut against the lower flat surface 24 of the wedge 20 and move the same upwardly in FIG. 3 into its wedging and securing position with the arm 15 and the shaft 14 as illustrated in FIG. 3.

The bore 19, wedge 20 and set screw 23 are so constructed and arranged that when the same are disposed in the wedging and securing relation illustrated in FIG. 3, the wedge 20 and set screw 23 are completely embedded within the arm 15 so that the same do not project externally thereof and thereby provide a hindrance to the rotational movement of the rocker arm 15 as might be the case if the same projected from the arm 15.

In order to maintain the wedge 20 in a proper wedging position relative to the opening 18 through the rocker arm 15 when the rocker arm 15 is unattached from the shaft 14 of the actuator so that the wedge 20 will have its wedging surface 21 facing in the proper direction for subsequent wedging action against the shaft 14 when the rocker arm is again telescoped thereon, an orienting pin or rod 25 is provided and is adapted to be press fitted within another opening 26 passing through the arm 15 and being so positioned that when the pin 25 is disposed within the opening 26, the pin 25 is located across the bore 19 in such a manner that the same is adjacent the wedging surface 21 of the wedge so as to prevent the wedge 20 from turning or rotating within the bore 19. The pin when inserted in the opening 26 is also fully embedded within the rocker arm 15 so as not to project therefrom and hinder the operation of the rocker arm 15.

Therefore, it can be seen that when it is desired to adjust the position of the rocker arm 15 relative to the shaft 14 in either a rotational direction or an axial direction thereon or both, the set screw 23 is partially unthreaded or rotated in an unthreading direction by a suitable tool being inserted in the conventional opening 28 formed in the end 29 of the set screw 23 so that the cam or wedge surface 21 of the wedge 20 will be backed off from wedging relation with the shaft 14 and arm 15 to permit rotational or axial movement therebetween. Once the desired position of the actuator arm v15 relative to the shaft 14 has been attained, the set screw 23 is again tightened within the bore 19 to cause the wedge 20 to fully wedge between the shaft 14 and the arm 15 in the manner illustrated in FIG. 3 to firmly secure the shaft 14 and rocker arm 15 together so that the same will move in unison for the reasons previously set forth.

As previously stated, should the rocker arm 15 be completely removed from the shaft 14 in the manner previously described, the wedge 20 is maintained in a proper orientation with the opening 18 of the arm 15 by the locating pin 25 so that when the arm 15 is again assembled on the actuating shaft 14, the wedge 20 will be in the proper position for causing wedging action therebetween in the manner previously set forth.

Thus, it can be seen that this invention provides an improved means for securing a rocker arm to an actuating shaft of an acutator for a limit switch construction or the like.

While the form of the invention now preferred has been illustrated and described as required by the Patent Statutes, other forms may be utilized and all come within the scope of the appended claims.

What is claimed is:

1. In an actuator for a limit switch construction or the like having a rotatable actuating shaft and a rocker arm carried thereby and having an opening passing therethrough and telescopically receiving said shaft therethrough, the improvement comprising a wedge carried by said arm, means for wedging said wedge between said shaft and said arm at said opening to secure said shaft and said arm together, and means carried by said arm to orient said wedge to a wedging position for said shaft when said arm is unattached to said shaft, said last-named means comprising means disposed inside said arm and disposed adjacent the wedging surface of said wedge to prevent said wedge from turning relative to said opening.

2. In an actuator for a limit switch construction or the like having a rotatable actuating shaft and a rocker arm carried thereby and having an opening passing therethrough and telescopically receiving said shaft therethrough, the improvement comprising a wedge carried by said arm, means for wedging said wedge between said shaft and said arm at said opening to secure said shaft and said arm together, and means carried by said arm to orient said wedge to a wedging position for said shaft when said arm is unattached to said shaft, said last named means comprising a pin carried by said arm and disposed adjacent the wedging surface of said wedge to prevent said wedge from turning relative to said opening.

3. In an actuator as set forth in claim 1, the further improvement wherein said arm has a bore formed therein and intersecting with said opening, said wedge being disposed in said bore.

4. In an actuator as set forth in claim 3, the further improvement wherein said bore is transverse to said opening and offset relative to said opening.

5. In an actuator as set forth in claim 3, the further improvement wherein said arm has a threaded portion in said bore, said means for wedging said wedge comprising a threaded member threaded in said threaded portion of said bore.

6. In an actuator as set forth in claim 5, the further improvement wherein said threaded member abuts said wedge to cause wedging movement thereof. I

7. In an actuator as set forth in claim 1, the further improvement wherein said wedge and said means for wedging said wedge and for orienting said wedge are entirely embedded in said arm so as not to project externally thereof.

8. In an actuator for a limit switch construction or the like having a rotatable actuating shaft and a rocker arm carried thereby and having an opening passing therethrough and telescopically receiving said shaft therethrough, the improvement comprising a wedge carried by said arm, means for wedging said wedge between said shaft and said'arm at said opening to secure said shaft and said arm together, said last-named means and said wedge being entirely embedded in said arm so as notto project externally thereof, and means disposed inside said arm and being disposed adjacent the wedging surface of said wedge to prevent said wedge from turning relative to said opening when said arm is unattached to said shaft.

9. In an actuator for a limit switch construction or the like having a rotatable actuating shaft and a rocker arm carried thereby and having an opening passing therethrough and telescopically receiving said shaft therethrough, the improvement comprising a wedge carried by said arm, means for wedging said wedge between said shaft and said arm at said opening to secure said shaft and said arm together, said last-named means and said wedge being entirely embedded in said arm so as not to project externally thereof, and a pin being carried by said arm and being disposed adjacent the wedging surface of said wedge to prevent said wedge from turning relative to said opening when said arm is unattached to said shaft.

10. In an actuator as set forth in claim 9, the further 13. In an actuator as set forth in claim 1 l, the further improvement wherein said arm has a threaded portion in said bore, said means for wedging said wedge comprising a threaded member threaded in said threaded portion of said bore.

14. In an actuator as set forth in claim 13, the further improvement wherein said threaded member abuts said wedge to cause wedging movement thereof.

Claims

6. In an actuator as set forth in claim 5, the further improvement wherein said threaded member abuts said wedge to cause wedging movement thereof.

8. In an actuator for a limit switch construction or the like having a rotatable actuating shaft and a rocker arm carried thereby and having an opening passing therethrough and telescopically receiving said shaft therethrough, the improvement comprising a wedge carried by said arm, means for wedging said wedge between said shaft and said arm at said opening to secure said shaft and said arm together, said last-named means and said wedge being entirely embedded in said arm so as not to project externally thereof, and means disposed inside said arm and being disposed adjacent the wedging surface of said wedge to prevent said wedge from turning relative to said opening when said arm is unattached to said shaft.

10. In an actuator as set forth in claim 9, the further improvement wherein said pin is entirely embedded in said arm so as not to project externally thereof.

11. In an actuator as set forth in claim 8, the further improvement wherein said arm has a bore formed therein and intersecting with said opening, said wedge being disposed in said bore.

12. In an Actuator as set forth in claim 11, the further improvement wherein said bore is transverse to said opening and offset relative to said opening.

13. In an actuator as set forth in claim 11, the further improvement wherein said arm has a threaded portion in said bore, said means for wedging said wedge comprising a threaded member threaded in said threaded portion of said bore.