US3749870A

US3749870A - Elastomeric cover for a pendant switch with an untensioned intermediate position

Info

Publication number: US3749870A
Application number: US00195316A
Authority: US
Inventors: L Oakes
Original assignee: Joy Manufacturing Co
Current assignee: Cooper Industries LLC; Joy Manufacturing Co; Citibank NA
Priority date: 1971-11-03
Filing date: 1971-11-03
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31

Abstract

A switch device having a plurality of compact multiple position push button switches housed in a common pendant station to control a plurality of circuits.

Description

1 llmte States Patent 1191 1111 3,749,870 Oakes July 31, 1973 ELASTOMERIC COVER FOR A PENDANT 3,086,090 4/1963 Carroll 200/168 0 x SWITCH WITH AN UNTENSIONED 332 228 f a 200/168 G anerare a .1 INTERMEDIATE POSITION 3,592,980 7/1971 Alamprese 200/153 LA X [75] Inventor: Lloyd Oakes, New Philadelphia,

Ohio FOREIGN PATENTS OR APPLICATIONS 1,058,681 2/1967 Great Britain 200/168 G [73] Asslgnee' l r j' 'gg gg Company 610,415 12/1960 Canada 200/168 0 22 F' l 7 1 Nov 9 1 Primary ExaminerRobert K. Schaefer [21] Appl. NO-Z 195,316 Assistant Examiner-Robert A. Vanderhye Attorney-E. Wallace Breisch [52] US. Cl. 200/168 G, 200/157 [51] Int. Cl. 1101b 13/06 [58] Field 61 Search 200/159 B, 168 G, [571 ABSTRACT 200/159 153 5 157 A switch device having a plurality of compact multiple a position push button switches housed in a common [56] References cued pendant station to control a plurality of circuits. I

UNITED STATES PATENTS 2,870,273 1/1959 Merchant 200/153 LA X 5 Claims, 16 Drawing Figures PATENIEUJULM I973 FIGIBT'H 54 SHEEI 2 OF 3 FIG /6 PAIENIEDJUL 3 I ma SHEET 3 0F 3 FIG.

FIG. 7

FIG. 6

//2 EHO FIG: /0

L u-es FIG: /3

ELASTOMERIC COVER FOR A PENDANT SWITCH WITH AN UNTENSIONED INTERMEDIATE POSITION BACKGROUND OF INVENTION In industrial applications such as controls for overhead electrical cranes and electrical hoists, it has been found desirous to have a single control station where switches may be housed to selectively control such equipment in movement to different positions and at different speeds. Various types of control panels or pendant control switch units have been utilized, all of which have been confronted with problems of space requirements necessitated by the use of a large number of switch devices to control a large number of desired control functions.

SUMMARY OF INVENTION According to the present invention, there is provided a new and improved pendant switch unit having a novel casing for housing a plurality of multiple position switches to be manually adjusted such that each switch controls a separate control function with a multiple choice of speeds by use of a single new and novel economical space-saving push-button device.

Other provisions of this invention will be more apparent when studied in conjunction with the following detailed description and accompanying drawings wherein: 7

FIG. 1 is a plan view of the novel pendant switch casing;

FIG. 2 is a side elevational view of the pendant switch casing partly in section;

FIG. 3 is an end elevational sectional 'view of the switch casing;

FIG. 4 is a perspective view of a switch unit;

FIG. 5 is front elevational view of a switch unit;

FIGS. 6 and 7 are respectively side and bottom elevational views of an internal switch;

FIG. 8 is a top elevational view partly in section of the switch unit;

FIG. 9 is a front sectional view of FIG. 8 taken along the line 9-9;

FIG. 10 is a plan view of a switch actuator;

FIGS. ll, 12 and 13 are respectively top, end and bottom elevational views of the switch actuator of FIG. 10;

FIGS. 14 and 15 are respectively side and end elevational views of a switch interlock;

FIG. 16 is a proposed schematic of the wiring circuit of a switch unit.

Referring to FIG. 1 there is shown a pendant switch device 10 having a plurality of push button switches 12 housed within a casing 14 in a linear manner. The switches 12 are arranged in pairs as switch units 16 as can be seen in FIG. 2, each unit 16 controlling a specific operation while the individual switches 12 of each unit 16 control the speed and direction of the specific operations as explained hereinafter.

The casing 14 as seen in FIGS. 1, 2, 3 is formed of two elongated channel shaped

halves

18 and 20 of metal such as steel. Although the casing 14 is usually utilized in a vertical position, for purposes of description, it is shown herein in FIGS. 1, 2 and 3 in a horizontal position wherein one half is referred to as the upper half 18 while the other half is referred to as the lower half 20. With the exception of the inside upper surface 22 of the upper half 18 and the inside bottom surface 24 of the lower half 20, the casing 14 is completely encased in a cover 21 of an elastomeric molded material such as neoprene so as to have the entire outside of said casing 14 electrically non-conductive. The ends of the channel halves are closed in with the neoprene to give the casing an insulated rectangular shape with a cable entry opening 25 in one end. The dimensions of the casing 14 are predetermined to house a predetermined number of switch units 16, shown herein in FIGS. 1 and 2 as three units providing six push buttons. Although shown as a six button combination, any desired number of buttons may be provided.

When assembled as shown in FIG. 2, the switch units are secured to the inside surface 22 of the upper half 18 by suitable means such as screws (not shown) and the top and

bottom halves

18 and 20 are securely bolted together by means such as bolts 26 to bind the outer edges 27 of the casing in a water-tight fashion with suitable overlapping surfaces (not shown). A plurality of openings 28 in the metallic portion of the inside upper surfaces 22 permit the push button stems 30 of the switch units 16 to extend therethrough a distance of half of its hereinafter described operating travel such that the stems 30 can be selectively positioned from a fully extended non-operating or unactuated position as shown in FIG. 2 at 32, through a series of operating positions representing different operating speeds explained hereinafter, to a full operating position shown at 34 in FIG. 2

Flexible neoprene button diaphragms 36 (FIGS. 1, 2 and 3) are integrally molded to the neoprene cover 21 across the openings 28 in the upper half 18 of the casing 14 with a solid mold to prevent water, dust or dirt from entering the inside of the assembled casing 14 and fouling the switch units 16 therein. The molding application of these button diaphragms 36 is unique in that the natural positions of the diaphragms 36 are initially formed in the same plane as the surface of the upper half 18 of the casing 14 in a manner such that when the switch units 16 are in position within the assembled casing 14, the button stems 30 engage the center area of the diaphragm 36 and cause it to be distended outwardly from the casing 14 to an unactuated nonoperating position, a distance of half the operating travel of the button stem 30. A spring 38 (within the switch unit 16 described hereinafter) tends to maintain the button stem 30 and the button diaphragm 36 in this outward extending non-operating position. As seen at 32 in FIG. 2 during operation of the switch units 16 (explained hereinafter) the button diaphragm 36 and the engaged button stem 30 are manually pushed towards the inside of casing 14 through a series of switch operating positions (hereinafter described) towards the inside of casing 14 to a position at 34. The movement of the diaphragm 36 passes from an outwardly distending state at 32 through its described natural position halfway through the button stem operating travel and then continues on to be distended inwardly the remaining half of operating travel to a full operating position of the button stem 30 at 34. Release of manual pressure on the diaphragm 36 permits the spring 38 to return the button stem 30 and engaged diaphragm 36 to be returned back through the operating travel distance to the outwardly extended non-operating position at 32. This novel arangement of the diaphragm 36 permits a wide range of operating travel of the diaphragm 36 without putting any severe internal stress thereon and thereby lengthens the operating life of the diaphragm 36. A plurality of protective bumpers 37 are suitably located surrounding the openings 28 to prevent damaging of the button stem 30.

The end view of FIG. 3 illustrates one shape of the diaphragms 36 as located in the openings 28 of the upper half 18.

The switch unit 16 as shown in FIG. 4 consists of a non-conductive container 40 made of a sturdy material such as a phenolic resin, with a cover 41 made of metal such as aluminum and secured across the top of the switch container 40 by screws 42. As viewed in FIGS. 4 and the front side 44 of each switch unit 16 has a terminal strip 46 secured thereto by screws 48. Terminal strips 46 include a plurality of terminal screws 50 each of which may be connected by suitable wiring to precision switches within the container 40, back to selected terminal screws 50, and thence via selected wir ing (not shown) making up a multiple connector cable 52 (FIG. 1) leading from the pendant casing 14 to the equipments desired to be controlled as further described hereinafter. A plurality of mounting brackets 54 are formed in the top (FIG. 4) of the container to provide means for securing the switch units 16 to the inside upper half 22 of the casing 14 when the pendant switch device is assembled.

Housed within the container 40 of each switch unit 16 is a plurality of precision switches 56 (FIGS. 6 and 7) arranged in two sets 58 (only one of which is shown in FIGS. 8 and 9) in

separate compartments

60 and 62 of the container 40. The switch sets 58 include a plurality of switches 56 arranged side by side in each of the

compartments

60 and 62 as shown in FIGS. 8 and 9 wherein the set 58 is comprised of five individual switches maintained in position by a pair of

retaining rods

64 and 66 shown in FIG. 8 with the relative position of the ends thereof shown in FIG. 4. Although five switches are shown and described herein, it should be noted that a lesser number of switches may be utilized with appropriate spacing means as necessary for specific control requirements.

As shown in FIGS. 6 and 7, the switches 56 are well known precision micro-switch mechanisms (not shown) contained in compact non-conducting housing 68 with

external switch terminals

70 and 72 and an engaging roller 74 mounted on a movable arm 76 to pivotally position responsive to push button action explained hereinafter, to move a contactor 78 inwardly against an internal spring action and operate the usual internal switch mechanism selectively to a circuit closed or open position.

A push button actuator 80 is slidably positioned in an elongated guide cavity 82 formed in the walls and a dividing section 83 of the container 40. The positioning of push button actuator 80 is shown in FIGS. 8 and 9 wherein the bottom portion of FIG. 8 with the cover 41 cut away illustrates the position of the push button actuator 80 with respect to the guide cavity 82 and one set 58 of precision switches 56, while the top portion of FIG. 9 illustrates the relative position of the push button actuator 80 with respect to the spring 38, and the cavity 82 in the switch compartment 62.

The push button actuator 80 (FIGS. 10, ll, 12, 13) is made of non-conductive plastic material having a button stem 30, a guide 86 and an intermediate cam portion 88. The cam portion 88 consists of a plurality of

inclined camming surfaces

90, 92, 94, 96, 98 arranged side by side with each cam surface beginning its angle of inclination at a different distance below the top 89 of the cam portion 88. The cam surfaces 90-98 are located on each of the cam portions 88 which are slidable in the cavity 82 within each

switch compartment

60, 62 adjacent to the roller 74 of a set of switches 56 to engage each roller 74 of a switch set to effect closing of each switch mechanism thereof in a pre-selected sequence as the actuator is manually moved into the cavity 82 and in a reverse sequence of opening as a spring 38 moves the actuator 80 outward of the cavity 82 when manual pressure is released as described further hereinafter. One sequence of the effectiveness of the cam surfaces is shown in the FIG. 10, however various pre-selected locations of the cam surfaces below the top 89 can be prearranged in the forming of the actuators as desired. Each of the actuators 80 is maintained in position within the switch compartments against the forces of springs 38 by the cover 41, with the button stems 84 projecting through openings 102 and 104 therethrough.

An elongated slot 106 is provided in the divider 83 (FIG. 9) between the two

switch compartments

60 and 62, with

elongated guide slots

107 and 108 extending perpendicular therefrom opening into each of the said

switch compartments

60 and 62. A disc shaped switch interlock 110 (FIGS. 14, 15) having a suspension pin 112 extending perpendicular therethrough and eccentrically located near the periphery of the disc, is positioned with the pin 112 riding in the slot 106. The sides of the disc interlock 110 extend through the

guide slots

107 and 108 into the switch compartments 60 and 62 on either side of the divider 83. If either one of the actuators 80 are manually moved inwardly, the cam portion 88 thereof will engage the extended side of the disc interlock 110 in the respective switch compartment to thereby pivot the interlock 110 about the suspension pin 112 into the opposite switch chamber to thereby permit the moving actuator 80 to pass by the interlock to permit the cam surfaces -98 to engage their respective rollers 74 to operate the switch set in that particular switch compartment. The pivotal movement of the interlock into the opposite switch compartment will prevent the adjoining actuator 80 (operative therein) from being manually moved inward against the disc and thereby providing an interlock operation whereby only one actuator 80 may be moved inwardly at any one time.

An example of the type of circuitry that may be controlled by this device is shown in FIG. 16 utilizing six internal circuits with lead wires omitted. Normal lead wires extend from the various switch units 16 to form a cable 52 (FIG. 1) which extends from the switch casing 14 to units to be controlled. A hanger 114 is provided on casing 14 to conveniently locate the casing as desired.

As seen in FIG. 2, the switch units 16 are secured side by side to the inside surface 22 of the upper half of the casing 14 by the screws mounted in the brackets 54 on the switch container 40. According to the control circuit requirements, the switch units are selectively wired from incoming and return wires (not shown) in the cable 52 (FIG. 1) to the selected terminal screws 50 on the selected terminal strips 46 (FIG. 4) for the desired switch 56. An example of the internal wiring is shown in FIG. 16 wherein the terminal strip 46 and switches 56 are shown in part as a simplified dotted block form. The selection of the specific switch circuit is made in accordance with the specific control requirements such that each actuator 80 operates a single control operation with each control operation have specific degrees of control, such as different degrees of speed of motor operation, which are controlled in predetermined steps by selective operation of each switch 56 of each switch set 58 associated with the actuator 80 being utilized. An example being one switch unit 16 having the shown two push button actuators wherein the interlock 110 (previously described) prevents both from being actuated at the same time, however, one actuator may be moved inwardly different degrees to select different motor speeds in one direction while the second actuator of the same unit may be moved inwardly different degrees to select different speeds of the same motor but in the opposite direction.

in describing the operation of the actuators 80 with respect to the switch sets 58 it should be noted, that as viewed in FIG. 9 an actuator 80 is associated and operates with the shown switch set 58 although for purposes of description is not shown. Similarly, a switch set 58 operates and is associated with the shown actuator 80 although for simplicity of description is not shown therewith.

In operation, as an actuator 80 is manually moved inwardly within the switch compartments 60 or 62, the cam portion 88 slides within the guiding cavity 82 to an engaging position where the cam surface furthermost from the top 89 of the cam portion 88, engages a cam roller 74. As viewed in FIGS. 8, 9 and 10 the cam surface 94 is the first surface to engage a roller 74 and therefore is the first of the switches 56 of that particular switch set 58 to bperatively closed by action of the roller 74 on the contactor 78. Viewing the drawings it can be seen that the cam surfaces 94, 96, 92, 98 and 90 engage the associated rollers 74 and move the contactors 78 in that sequence such that the associated switches 56 will be operatively closed inthat orderv as the actuator 80 is manually moved upwardly by pressing on the button stem 30 thereof. Releasing the button stem 30 permits the associated spring 38 to return through the reverse sequence of opening the switches associated with the cam surfaces 90, 98, 92, 96 and 94 in that order. The spring 38 returns the button stem 30 to its nonoperating position 32 to bias the button diaphragm 36 to its outwardly extended position. It can thus be seen that by selective wiring of the switches, a forward and reverse sequence of control operation can be effected for a single unit such as a crane motor with the speeds thereof being sequentially increased as the actuator 80 is pushed inwardly, and the motor speeds being sequentially decreased as the actuator 80 is released and returned to its non-operating position by the spring 38.

The spacing and locating of the respective cam surfaces can be varied as desired to effect different sequences of different controls to meet any needs. The pair of actuators in each switch unit 16 should normally control the same motor at sequential speeds forward for one actuator and sequentially in reverse speeds for the second actuator. The plurality of switch units 16 in one casing 14 provides for a single compact remote control station for a plurality of motors performing separate functions.

Since numerous changes may be made in the abovedescribed construction and different embodiments of the invention may be made by addition, elimination or relocation of switch units, switch chambers and cam surfaces without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description as shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An electrical switch comprising, in combination: an insulated housing; at least one switch means located within said housing; said switch means having actuating means substantially lineraly movable in opposite directions and biased in one of said directions; said housing having integral deformable elastomeric web means overlying said actuating means and flexible in at least said opposite directions; said actuating means being normally biased in said one direction and in said normally biased position engaging and biasing said web in said one direction into a tensioned state from an untensioned state thereof; and upon movement of said actuating means a predetermined distance in a direction opposite said one direction said web means passes from the tensioned state thereof at least to said untensioned state.

2. The combination set forth in claim 1 further characterized in that said switch means includes a plurality of contactor devices axially aligned in a common plane.

3. An electrical switch as specified in claim 1 wherein upon movement of said actuating means said predetermined distance said web means passes from the tensioned state thereof through said untensioned state and into an oppositely tensioned state.

4. An electrical switch as specified in claim 3 wherein said untensioned state is at a distance substantially equidistant from the extreme tensioned and oppositely tensioned stae of said web means.

5. An electrical switch as specified in claim 1 wherein said actuating means engages said web means at a central location of said web means.