Illuminated push-pull switch operator

Oct. 14, 1969 j. e. stallman 3,472,986 illuminated push-pull switch operator

Filed Feb. 12, 1968

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United States Patent Office

3,472,986

Patented Oct. 14, 1969

3,472,986 ILLUMINATED PUSH-PULL SWITCH OPERATOR Janies E. Stallman, Whitefish Bay, Wis., assignor to Square D Company, Park Ridge, III., a corporation of Michigan Filed Feb. 12, 1968, Ser. No. 704,728 Int. Cl. HOlh 9/16, 9/18

U.S. Cl. 200—167 9 Claims

ABSTRACT OF THE DISCLOSURE

An illuminated push-pull switch operator having a tubular operating stem which is resiliently maintained in selected operating positions in a base by spring biased cam members that move in a circumferential path about outer surface portions of the stem.

This invention relates to push-pull type switch operators and more particularly, to a switch operator which has a linearly movable tubular stem and a means for resiliently maintaining the stem in at least one position against linear movement in a base.

Devices known as heavy duty oil tight push button selector switches and the like which are furnished by manufacturers for industrial type control frequently are designed to use a minimum number of separate components which may be readily modified and combined to provide a maximum number of selected switching functions. To achieve the desired flexibility, the oil tight switching apparatus combination usually includes one or more individual contact blocks each of which has a linearly movable plunger and movable contacts within the block to achieve the desired switching function and a manually operated switch operator to move the switch plunger. Additionally, the combination may include an element known as a light module which is provided if an illuminated switch operator is desired. An example of a contact block which may be used with the operator according to the present invention is shown in a United States Patent No. 3,336,455, filed May 5, 1965 and issued Aug. 15, 1967 which has been assigned by the inventors Merlin Y. Turnbull, Josef Bierenfeld and Carl B. Sohns to the assignee of the present invention. The operator according to the present invention may be used as a replacement for the switch operator shown in Turnbull et al. patent or the operator shown in United States Patent No. 3,320,393 which was filed Nov. 15, 1965 and issued May 16, 1967 and also assigned by the inventors Carl B. Sohns and Josef Bierenfeld to the assignee of the present invention. Additionally, if desired, the operator according to the present invention may be used with a light module in a manner disclosed in United States Patent No. 3,315,060, filed Nov. 8, 1965 and issued Apr. 18, 1967, which was assigned by the inventors Richard D. Rothweiler, Josef Bierenfeld and Carl B. Sohns to the assignee of the present invention, if an illuminated form of the switch operator is desired.

The present invention relates to devices commonly known as push-pull operators which may be used instead of two or more switching operators, as are more commonly used in motor control circuits. A typical installation wherein the switch operator according to the present invention may be used in a motor control circuit is accomplished by arranging the electrical connections to the switches operated by the switch operator so the motor will start when the operating button of the operator is manually pulled outwardly from a central or neutral position and the motor will stop when the operating button is pushed inwardly past the neutral position. The operator structure further includes readily interchangeable parts which will cause the operator parts to be resiliently maintained in both the pulled-out and the pushed-in positions, or will cause the operator parts to be resiliently maintained in the neutral position or combinations thereof, as desired.

It is an object of the present invention to provide a self-contained switch operator which may be attached to other switching units to provide a switching assembly and wherein the operator includes a plurality of members which are movable in a circumferential path about a tubular operating stem to resiliently maintain the stem in one or more positions in a passage through a base of the operator.

Another object is to provide a self-contained push-pull button operator for actuating switch contacts in a separate contact block which is attached to the operator to provide a switching assembly and to provide the operator with a tubular stem of translucent material so a translucent button carried on the stem may be illuminated and to resiliently maintain the stem in one or more selected positions in a passage through a base of the operator with a means that includes at least one pair of cam members which are carried in an annular groove in the base.

Further objects and features of the invention will be readily apparent to those skilled in the art from the specification and appended drawing illustrating certain preferred embodiments in which:

FIG. 1 is a cross sectional view of a switch operator incorporating the features of the present invention.

FIG. 2 is a view partly in cross section, generally taken along line 2—2 in FIG. 1.

FIG. 3 is a front elevational view of a portion of a tubular stem operator together with one form of a cam indexing structure used in the structure shown in FIG. 1.

FIG. 4 is a front elevational view of a portion of a tubular stem together with a modified form of the cam indexing mechanism shown in FIG. 3.

Referring to FIG. 1 of the drawings, the switch operator 10 includes a metal base 12 having a forward end 14, a rear end 16 and a passage 18 extending therethrough between the forward end 14 and the rear end 16. At its rear end 16 the base 12 is provided with circumferentially spaced bosses 20 which are internally threaded, as indicated at 22, for cooperation with suitable bolts, not shown, and an adapter 26 for securing the base 12 to switches 28 in a manner as described in the Turnbull et al. patent.

The forward end 14 of the base 12 has an inwardly extending annular flange 30 restricting the forward end of the passage 18 and providing an upper wall of an annular groove 32 which has a lower wall provided by an annular washer 34. An annular seal 36 having a Vshaped cross section is positioned within the groove 32 to engage with a sealing engagement outer wall portions of a tubular stem 38 that extends through the passage 18. Extending rearwardly of the washer 34 the passage 18 includes an enlarged annular portion or annular groove 40, the top wall of which is provided by the washer 34 and the bottom wall of which is provided by a cam member retainer 42. The retainer 42 is annular in shape and is held fixed within the passage 18 by staking inner wall portions of the base 12 over a bottom surface of the retainer, as indicated by the numerals 44.

Suitably secured to a forward end of the stem 38 is a head portion, or operating button 46. As shown, the outer surface of the forward end of the stem 38 is provided with an externally threaded portion 48 which receives an internally threaded portion on the button 46 thereby uniting the button 46 and the stem 38 into a single assembly with an annular seal 50 being provided to preclude travel of undesirable fluids from the exterior of the stem

3,472,986 about the threaded portion 48 into the interior of the tubular stem 38.

The stem 38 is guided for axial movement in the passage 18 by inner annular wall portions of the flange 30 and the retainer 42 with entry of fluids flow about the stem 38 into the passage 18 being prevented by the seal 36. The movement of the button 46 and the stem 38 rearwardly in the passage 18 is limited by engagement between a rearwardly located annular surface 52 on the button 46 and the forward end 14 of the base 12.

In order to limit the forward movement of the stem 38 relative to the base 12, a retainer 54 is connected to the rearward end of the stem 38. The retainer 54 is arranged to engage the bottom surface of the retainer 42 to limit the forward movement of the stem 38 in the passage 18.

The retainer 54, as disclosed in the Sohns et al. patent, is annular in shape and has an internal annular bead or shoulder extending radially inwardly from its inner periphery and terminating axially in spaced relation to the .rear end of the retainer 54. The rear end of the stem 38 is provided with a radially open annular groove 56 and a tapered guiding nose portion 58. The stem 38 has two axially extending notches 60 extending through its peripheral wall. The retainer 54 is provided with radially extending tongues which are receivable in the notches 60 with circumferential clearance. The notches 60 impart a certain flexibility to the extreme rear end of the stem 38. The stem 38 and the retainer 54 are made of relatively stiff, but slightly resilient, self-restoring material. The stem 38 and retainer 54 can be assembled by pressing the retainer 54 forward end foremost over the tapered guiding nose portion 58 of the stem 38, thus contracting the rear end of the stem 38 radially and expanding the retainer 54 until a rib on the retainer 54 passes into alignment, radially of the stem, with the groove 56. Thereupon the retainer 54 and the stem 38 approach fully restored condition, seating the rib firmly in the groove 56. The tongues on the retainer 54 fit the notches 60 with very limited circumferential clearance when the stem 38 is contracted. Hence, when the retainer 54 is snapped into place, the notches 60 in the rear end of the stem 38 firmly engage the tongues on the retainer 54 and assure that when the retainer 54 is self-restored to its original condition, it is constrained from rotation relative to the stem 38.

As shown in FIGS. 2, 3, and 4, integrally formed to extend outwardly on opposite sides of outer surface portions of the stem 38 are cam pins 62 and 64. The cam pins 62 and 64 are identical and each includes a pair of oppositely facing rounded cam surfaces 66 which are spaced on opposite sides of a strengthening rib 68 extending tangentially and axially along the outer surface of the stem 38. Each of the pins 62 and 64 is provided with a raised portion 70 which engages the inner walls of the passage 18 to further guide the movement of the stem 38 in its movement in the passage 18.

Positioned on opposite sides of each of the cam pins 62 and 64, as shown in FIG. 2, is a pair of cam members. The pair of cam members positioned on the opposite sides of the cam pin 62 are designated by numerals 72 and 74. Similarly, cam members 76 and 78 are positioned on opposite sides of the cam pin 64. The cam members 72, 74, 76, and 78 are identical and each is arcuately shaped to be received in the groove 40 and movable in the groove 40 in a circumferential path about an outer peripheral surface of the stem 38. The cam members 72, 74, 76 and 78 each has a cam surface on one end and a notch on an end remote from the cam surface. In FIGS. 3 and 4, the notches are designated by the numeral 80. The cam surfaces in FIG. 3 on the illustrated cam members 72 and 74 are designated as 72α and 74α, while in FIG. 4 the cam surfaces on a pair of cam members 73 and 75 are designated as 73α and 75α. It is to be appreciated that an additional pair of cam members, not shown having similar cam surfaces as cam members 73 and 75 are used in the structure in FIG. 4 to provide the functions provided by the cam surfaces 72α and 74α in FIG. 3 and the cam surfaces 73α and 75α in FIG. 4, as will be later described. If desired, portions of the cam members 72-76 and 78 may be removed as designated by the numeral 82 for mechanical clearance purposes. As shown in FIGS. 2 and 3, the cam members 72 and 74 are positioned in the groove 40 on opposite sides of the cam pin 62 so that the cam surfaces 72α and 74α confront each other with the cam pin 62 being positioned therebetween. The cam members 76 and 78 shown in FIG. 2 are similarly disposed in the groove 40 so the cam surfaces thereon confront each other with the pin 64 positioned therebetween.

The cam surfaces 72α and 74α each has a cam profile that is valley or V-shaped, providing a pair of inclined surfaces 84 and 86 extending in opposite directions from an apex 88. Similarly, the cam surfaces 73α and 75α each have a cam profile that is wedged or V-shaped, providing inclined surfaces 90 and 92 extending from an apex 94. In the embodiments shown in FIGS. 3 and 4, a pair of springs 96 are positioned within the groove 40 and each has opposite ends positioned within the notches 80 to urge the confronting cam surfaces 72α, 73α, 74α, and 75α into constant engagement with the cam surfaces 66 of their associated cam pins 62 and 64.

The assembly of the switch operator may be accomplished as follows. The operating button 46, which may be of translucent material and which may be provided with an ornamental annular bezel 98, is threadedly applied to the threaded portion 48 after the seal 50 is in position on the stem 38. The assembled button 46 and the stem 38 is then installed in the passage 18 as the tapered nose 58 is passed through central opening in flange 30. The seal 36 is positioned within groove 32 and washer 34 is moved into the position shown in FIG. 1. An assembly, consisting of the cam members 72, 74, 76 and 78 together with a pair of springs 96, is positioned within the annular groove 40 and the cam retaining member 42 is moved in position and there held by staking a portion of the base 12 as indicated by the numeral 44. When the foregoing parts have been assembled, the retainer 54 is secured to the rear end of the tubular stem 38 in a manner previously described.

The forward end of the base 12 is externally threaded, as indicated at 100 for receiving an internally threaded ring nut 102. The base 12 can readily be inserted through an opening in a panel 104 after the nut 102 is removed and oil seal washers 106 are positioned between a rear face of the panel and an annular external shoulder 108 on the base 12. After the base 12 and the washers 106 are thus positioned, a suitable indicia plate 110 having an annular opening may be positioned over the forward end 14 to be positioned between the front face of the panel and the nut 102 when the nut 102 is reapplied to the threads 100. If desired, the base 12 and the indicating plate 110 may be held against rotation relative to the panel 104 by a conventional projection-notch arrangement as is well known.

When a non-illuminated type of switch operator is required, the adapter 26 and one or more switches 28 are secured to the rear end of the switch operator 10 in a manner previously described and fully disclosed in the Sohns et al. patent. Each of the switches 28, as disclosed in the Sohns et al. patent, has a pair of upper stationary contacts, a pair of lower stationary contacts, and a movable contact carried by a switch plunger 112. The plunger 112 is spring biased outwardly of the housing of the switch 28. When the plunger 112 is moved inwardly to an intermediate position within the housing of switch 28, neither of the pairs of stationary contacts of the switch 28 is bridged by the movable contact so that the switch is in a circuit opening position. The components of the switch 28 and the switch operator 10 are arranged so that when the stem 38 is positioned as shown in FIG. 3, the switch

3,472,986 plunger 112 will position the movable contacts of the switch 28 in a circuit opening position. Thus as the operating button 46 is pulled outwardly of the base 12, the stem 38 will move upwardly and the cam surfaces 66 will move upon the inclined surfaces 84 and cause the g cam member 72 to move to the left against the force of one of the springs 96 while the cam member 74 moves to the right against the force of the other spring 96. The upward movement of the stem 38 in FIG. 3, which is limited by the engagement of the retainer 54 with the retain- jq er 42, is accompanied by an upward movement of the plungers 112, which causes the movable contacts within the switches 28 to complete circuits through the upper pairs of stationary contacts of the switches 28. When the manual force which is applied to button 46 is released, the 15 springs 96 will move the cam members 72 and 74 toward each other with a force which will cause the plunger 38 to move downwardly to the position wherein the rounded cam surfaces 66 are positioned in the apexes 88 to resiliently maintain the stem 38 in a neutral position within 20 the housing 12.

When a manual force is applied to the button 46 to move the button inwardly into the base 12 to a position wherein the surface 52 engages the flange 30, movement will be imparted to the stem 38 which will cause the cam 25 surface 66 to move on the inclined cam surface 86. The movement of the camming pin 62 will cause the cam members 72 and 74 to respectively move against the force of springs 96. When the button 46 is bottomed on the flange 30, the plungers 112 of the switches will be de- 30 pressed through the movement of the retainer 54 to a position wherein the lower set of stationary contacts of the switches 28 are bridged by the movable contact. When the force upon the button 46 is removed, the cam members 72 and 74 will automatically cause the stem 38 to 35 move upwardly to the position wherein the rounded surfaces 66 are positioned in the apexes 88 to again maintain the stem 38 in a neutral position. Thus in the embodiment shown in FIG. 3, a continued manual force must be applied when the button 46 is either pulled out- ⁴⁰wardly of the base 12 or pushed inwardly into the base 12 and the camming arrangement, including the camming pins 62 and 64, together with the cam members 72, 74, 76 and 78, will constantly urge the movement of the stem 38 to a neutral position wherein the contacts of the 45 switches 28 are in a circuit opening position.

When the cam members shown in FIG.4 are utilized in the switch operator 10, the cam members 73 and 75 will maintain the stem 38 in an upper position in the base 12, as shown in full lines, or in a lower position, as 50 shown by the broken-lined cam member 62α. When the elements of the switch operator 10 are positioned as shown in full lines in FIG. 4, the button 46 and the stem 38 will be in the pulled-out position relative to the base 12 and the upper set of contacts of the switch 28 55 will be in a circuit closing position. When it is desired to open the upper set of contacts in the switches 28 and close a circuit through the lower set of contacts of the switches 28, the button 46 is manually moved inwardly in the base 12 toward the position wherein the cam pin 60 62 is positioned as shown in broken lines indicated as 62α. During the foregoing movement, the rounded surfaces 66 will initially pass over the inclined surface 90 and move the cam members 73 and 75 apart against the forces of the springs 96. When the rounded surface 66 65 passes beyond the apexes 94, the manual force which is applied to button 46 to move the stem 38 inwardly into the base 12, may be removed and the stem 38 will continue to move automatically to the broken-line cam pin 62α position as the force exerted by the springs 96 70 upon the cam members 73 and 75 urges the inclined surfaces 92 against the rounded surfaces 66 so that the stem 38 will move to its lower position and close the lower contacts of the switch 28.

When the elements, including the stem 38 and the 75 cam pin 62α of the switch operator 10, are positioned as shown in broken lines in FIG. 4, the button 46 and stem 38 will be in the push-in position relative to the base 12 and the lower set of contacts of the switch 28 will be in a circuit closing position. When it is desired to close the upper set of contacts in the switches 28 and open a circuit through the lower set of contacts in the switches 28, the button 46 is manually pulled outwardly from the base 12 toward the position wherein the cam pin 62 is positioned as shown in full lines. During the foregoing movement, the rounded surfaces 66 will initially pass over the inclined surface 92 and move the cam members 73 and 75 apart against the forces of the springs 96. When the rounded surface 66 passes beyond the apexes 94, the manual force which is applied to button 46 to move the stem 38 outwardly of the base 12, may be removed and the stem 38 will continue to move automatically to the full line cam pin 62 position as the force exerted by the springs 96 upon the cam members 73 and 75 urges the inclined surfaces 90 against the rounded surfaces 66 so that the stem 38 will move to its upper position and close the upper contacts of the switch 28.

The configuration and function of the cam members 76 and 78 as well as the cam pin 64 are identical to the cam members 72 and 74 and the cam pin 62. Thus a detailed explanation of the operation of the cam members 76 and 78 in response to the movements of the cam 64, in view of the preceding description of the operation of the cam pin 62 in response to the movement of the stem 38, is believed unnecessary.

If an illuminated version of the switch operator is desired, a light module as disclosed in the Rothweiler et al. patent is substituted for the adapter 26 and the switches 28 are attached to a rear surface of the light module. The light module includes suitable pins for transmitting motion between the retainer 54 and the operating plungers 112 of the switches and provides a support for a bulb 114 and suitable wire connections to cause the bulb 114 to be illuminated when the switch operator is in any one of the foregoing described positions in the manner disclosed in the Rothweiler et al. patent.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation.