SWITCH

Abstract

A switch is disclosed. In some examples, a switch includes a generally cylindrical housing; one or more sets of contact points enclosed by the housing; an indicator module, such as a multi-color LED illuminator, also enclosed by the housing; and a pushbutton actuator disposed to operate the contact points. The housing includes a display section spanning substantially the entire circumference of the housing such that the indication made by the indicator module is visible from all radial directions. When the pushbutton actuator is pressed, some of the contact points open to cut off power from hazards, while others are reconfigured to change the state of the indicator module to indicate the changed status of the switch. Multiple switches can be interfaced with each other, such as by serial connection, to facilitate multi-switch safety environment. Modular cables can be used to conveniently establish the interface.

Description

BACKGROUND

This disclosure relates generally to devices, such as an “emergency stop” device, which perform a machine function that is manually initiated during urgent situations that results in immediate or controlled cessation of machine motion or other hazardous situations.

In certain settings, quick, unobstructed access by personnel to emergency stop devices is required on all operator stations and other locations as determined by a risk assessment. Actuating an emergency stop device can remove all energy sources to hazards and overrides all other functions and operations in all modes.

An “emergency stop” device can take many forms, but typically is a pushbutton-operated device that is actuated by a single human action.

The present disclosure relates to pushbutton-operated emergency-stop device that is designed to facilitate high visibility, easy access and convenient safety system configuration.

SUMMARY

The present disclosure relates to a pushbutton-operated switch. In some configurations, a switch according to the present disclosure includes a generally cylindrical housing; one or more sets of contact points enclosed by the housing; an indicator module, such as a multi-color LED illuminator, also enclosed by the housing; and a pushbutton actuator disposed to operate the contact points. The housing includes a display section spanning substantially the entire circumference of the housing such that the indication made by the indicator module is visible from all radial directions. When the pushbutton actuator is pressed, some of the contact points open to cut off power from hazards, while others are reconfigured to change the state of the indicator module (e.g., change from yellow light to flashing red light) to indicate the changed status of the switch.

According to some aspects of the disclosure, multiple switches can be interfaced with each other, such as by serial connection, to facilitate multi-switch safety environment. Modular cables can be used to conveniently establish the interface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a switch according to one aspect of the present disclosure.

FIG. 2 shows a side view of the switch shown in FIG. 1.

FIG. 3 shows a bottom view of the switch shown in FIG. 1.

FIG. 4 illustrates a switch according to one aspect of the present disclosure with its illumination indicator indicating (e.g., by yellow light) that the switch is in its armed state.

FIG. 5 illustrates a switch according to one aspect of the present disclosure with its illumination indicator indicating (e.g., by flashing red light) that the pushbutton of switch has been pressed.

FIG. 6 shows a side view of a switch of the type shown in FIG. 1, with dimensions in one specific example according to this disclosure.

FIG. 7 shows a schematic diagram of the electrical configuration in a switch according to an aspect of the disclosure.

FIG. 8 schematically shows connection of two switches according to an aspect of the disclosure connected to an external device, such as a safety module, according to another aspect of the disclosure.

FIG. 9 schematically shows connection of multiple switches according to an aspect of the disclosure connected to an external device, such as a safety module, via modular cables according to another aspect of the disclosure.

FIG. 10 schematically shows modular cables according an aspect of the disclosure and their connections to switches according to another aspect of the disclosure.

FIG. 11 schematically shows modular cables according an aspect of the disclosure and their connections to switches according to another aspect of the disclosure. In this example, the switches includes no indicator (illuminator) for the state of the pushbutton.

DETAILED DESCRIPTION

In certain settings, quick, unobstructed access by personnel to emergency stop devices is required on all operator stations and other locations as determined by a risk assessment. Actuating an emergency stop device can remove all energy sources to hazards and overrides all other functions and operations in all modes

Under certain regulations, pushbutton-type device for emergency stop devices must be colored RED. The background immediately around pushbutton must be colored YELLOW. Emergency stop device must be continuously operable, clearly identified, clearly visible and readily accessible. The color RED for the emergency stop actuator cannot depend on illumination of the actuator (button).

Many pushbutton-type devices are mounted on control panels/enclosures at operator stations, but a significant number of pushbutton-type devices are also located remotely and require individual enclosures that house the pushbutton-type device and possibly other control and indicating devices. These remote, or stand-alone, enclosures are typically rectangular or square “boxes” that are constructed of metal or plastic.

In many applications, there are several individual pushbutton-type devices that are located in various positions on a machine (see, e.g., ANSI B11.19) or integrated manufacturing system (see, e.g., ANSI B11.20). In situations that require the actuation of the emergency stop function, typically a single pushbutton-type emergency-stop device is depressed. Once the situation is addressed, there may be difficulty in identifying the pushbutton-type device that was actuated (depressed) such that it can be reset allowing the machine or system to be placed in to operation.

Currently, there are two methods to identify an actuated pushbutton-type device other than the physical position of the button. These are a colored ring, typically GREEN, on the shaft of the button, or a RED colored indicator located in the face of the button that will illuminate either when the button is depressed or armed, depending on the installation.

The devices and methods according to some aspects of the present disclosure facilitate high visibility, easy access and convenient safety system configuration.

An exemplary pushbutton-type device includes illumination logic intended for quick identification of the status (armed or actuated) of the individual emergency stop button and optional indication of a machine or system stop.

When the button is armed, the housing (base) is illuminated yellow for high visibility while complying with the required yellow background requirement of an emergency stop indication. Once the button is actuated (depressed), the housing (base) will flash red to indicate the depressed button. This flashing red indication is unique in a standalone pushbutton-type device (i.e. no external signal or logic to create the flash sequence).

The illumination feature of the pushbutton-type device according to certain aspects of the present disclosure enhances the ability to comply with the requirements to clearly identify emergency stop pushbutton device and for it to be clearly visible. The user also has the option to have the housing (base) of an armed button to turn a steady red indication (from yellow) when a STOP condition exists by applying an external signal.

FIGS. 1-3 show a switch (100) according to one aspect of the present disclosure. FIG. 1 shows a perspective view of the switch (100); FIG. 2 shows a side view of the switch (100); and FIG. 3 shows a bottom view of the switch (100). The switch (100) in this example includes a housing (110) comprising a substantially rounded cylindrical wall section (102), which in some examples includes a light transmitting section (104). The switch (100) includes an electrical circuit (not shown in FIGS. 1-3) enclosed in the housing (102); the electrical circuit includes a pair of electrical contacts and an illuminating device. The switch (100) further includes an actuator, which in this example is a push button (120), which can be manually moved to open and close the pair of electrical contacts. The illuminating device is configured to be set to different states of illumination, such as on, off, steady, flashing and/or different colors, at least in part depending on the operation of the actuator (120) and is adapted to illuminate at least about a 50% circumferential portion of the light transmitting section (104). In the example shown in FIGS. 1-3, the illuminating device is adapted to illuminate circumferentially the entire light transmitting section (104).

The actuator in this example is configured to be manually moved relative to the housing (110) in at least two ways: linearly along the direction of an axis (106) of the housing (110) and in a twisting motion, as indicted by the directional indicia, in this example arrows (122) marked on the pushbutton (120), about the axis (160). Manual movements of the pushbutton (120) in this example sets the switch (100) in at least two different states: an armed state and an actuated state, which are explained in more detail below. For example, as illustrated in FIG. 4, positioning the pushbutton (120) farthest from the housing (110) sets the switch (100) in the armed state, in which the illuminating device in the electrical circuit emits light of one state of illumination (e.g., steady yellow) through the light transmitting section (104), indicating the armed state. Pressing the pushbutton (120) toward the housing (110) sets the switch (100) in the actuated state, in which the illuminating device in the electrical circuit emits light of another state of illumination (e.g., flashing red) through the light transmitting section (104), indicating the actuated state, as illustrated in FIG. 5. Once a pushbutton (120) is actuated (pressed), it is latched in the actuated position. Thereafter, a twist of the pushbutton (120) releases it back to the armed position.

The switch in some examples, such as the ones illustrated in FIGS. 1-3 and 6, further includes a mounting portion, such as a threaded mounting base or hub (130) protruding from the bottom of the housing (110) for securing the switch (100) to a suitable structure, such as a mounting bracket with a hole that accommodates the mounting base (130). The mounting base (130) in some embodiment have a sufficient size to ensure a robust support for the switch (100). In the particular example shown in FIG. 6, the threaded mounting base (130) is 30 mm in diameter, but a mounting base of any other suitable size can be used.

As further illustrated in FIGS. 1-3 and 6, the switch (100) also includes a connector 140 for attaching an electrical cable to the housing (110), thereby connecting the electrical circuit in the switch (100) to external circuits. Any suitable connector can be used. In the example in FIG. 6, an M12 Euro-style Quick Disconnect connector is used. As shown in FIG. 7(b), the connector in this example has eight electrodes (pins or sockets) (142-1 through 142-8). However, any suitable connector can be used.

FIG. 7(a) shows a schematic diagram of the electrical configuration in a switch (100) according to an aspect of the disclosure. The electrodes (142-1 through 142-8) of the connector (140) connects the electrical circuit in the switch (100). The connections to the electrodes in one example are as follows (including color codes for the wires):

	Pin	Color	Function
	1	White	AUX NO Output (Switched pin 2)
	2	Brown	+24 V dc (12-30 V dc)
	3	Green	Stop Signal input from safety module or
			machine +24 V dc (12-30 V dc)
	4	Yellow	CH2a
	5	Gray	CH2b
	6	Pink	CH1a
	7	Blue	0 V dc
	8	Red	CH1b

The electrical circuit includes an illuminating device (108), which is configured to generating light of different illumination states depending on the inputs A, B and C. The electrical circuit in this example further includes pairs of electrical contacts (750), which include contacts 750A, 750B and 750C; and electrical contacts (760). Contacts 750A and 760 are normally-open (“NO”) contacts, which are open when the switch (100) is in the armed state and closed in the actuated state; contact 750B and 760C are normally-closed (“NC”) contacts, which are closed when the switch (100) is in the armed state and open in the actuated state.

The contacts 750B and 750C are connected to external control circuitry, and cut off the connection between electrodes 4 and 5, and between 6 and 8, respectively, when the pushbutton (120) is actuated. Contacts 750A connects input B of the illuminating device (108) to the power supply (24V dc), thereby causing the illumination state to change to flashing red. The illumination state when the switch (100) is armed depends on the voltage at electrode 142-3 (or input C) as follows:

Situation	Indication*	Illumination Logic
Button Armed	YELLOW/	Indicates button is armed and machine is enabled to run or is running
Pin 3 open	STEADY
Button Pushed	RED/FLASH	Indicates the button that is pushed (actuated) and the machine is in an
Pin 3 open		Emergency Stop condition
Button Pushed	RED/FLASH	Indicates the button that is pushed (actuated) and the machine is in an
Pin 3 = +24 Vdc		Emergency Stop condition
		Signal on Pin 3 has no effect on a button that has been pushed (actuated)
Button Armed	RED/STEADY	Indicates the machine is in an Emergency Stop or other stop condition,
Pin 3 = +24 Vdc		but that specific button has not been pushed (actuated)
		This optional signal (+24 Vdc) allows the user to indicate an Emergency
		Stop or a normal stop condition by turning the YELLOW (steady) to a
		RED (steady) indication

FIG. 8 schematically shows connection of two switches (100A, 100B) according to an aspect of the disclosure connected to an external device, such as a safety module, according to another aspect of the disclosure. Multi-wire cables (890A, 890B) connect the connector (140A) of the switch (100A) to the connector (140B) of the switch (100B); another multi-wire cable (890C), in turn, connects the connector (140B) of switch (100B) to an external circuitry (880), which monitors the states of the contacts opened or closed by the pushbuttons (120) in the respective switches (100A and 100B). In this example, the outputs at electrodes 142-1 of the NO switches 760A and 760B in the switches (100A and 100B) are connected to a machine control (870). When either switch (100A or 100B) is actuated, the respective contact (760A or 760B) closes, and electrode 142-1 outputs a voltage (in this example 24 Vdc) applied to the corresponding electrode 142-2. The machine control (870), in response, produces an output that is applied to the external circuitry (880).

More than two switches can be interconnected according to certain aspects of the present disclosure. FIG. 9 schematically shows connection of three switches (100A, 100B and 100C) according to an aspect of the disclosure connected to an external device, such as a safety module, via modular cables (890A, 890B and 890C) according to another aspect of the disclosure. Modular cables can be single cables, such as the cable 890A, with connectors at two ends; modular cables can also be splitter-type cables, such as the cable 890B and 890C, each of which has a splitter (892B or 892C, respectively) and three connectors, one for the trunk, and one for each split branch. The connectors at the ends of the cables can be quick-disconnect-type connectors. Thus, the three switches (100A, 100B and 100C) can be interconnected in series as shown in FIG. 9 conveniently by coupling connector 894A of cable 890A with connector 894B1 of the splitter cable 890B; connector 894B2 of the splitter cable 890B with connector 894C1 of the splitter cable 890C; and connector 894C2 of the splitter cable 890C with a connector of the next switch or external circuitry (880). The detailed connections of individual wires of the connectors and splitters are shown in FIG. 10 according to another aspect of the disclosure.

FIG. 11 schematically shows modular cables according an aspect of the disclosure and their connections to switches according to another aspect of the disclosure. In this example, the switches (1100A and 1100B) include no indicators (illuminating devices) for indicating the armed or actuated state of the switches. The electrical circuit inside each switch (1100A or 1100B) includes only contacts (1150), which in this example include multiple pairs of NC contacts (1150A and 1150B) for opening and closing external circuits. Due to the simpler circuitry of the switches (1150A and 1150B), modular cables having fewer conductive wires can be used. In this example, a five-wire cable 1190A with a five-pin connector 1194A, as well as a four-wire splitter cable with four-pin connectors (1194B1 and 1194B2) and four-wire splitter, can be used.

The operating principles of certain exemplary devices of this disclosure are also demonstrated by the use of a testing tool, such as the DBQEZLPTL Demo Box EZ Light Pick To Light Demo Box/Power supply, available from Banner Engineering Corp., Minneapolis, Minn. However, the applications of the switching device of the invention are not limited to use in connection with any such testing tools.

Thus, switches, such as pushbutton emergency stop switches, that include illumination logic intended for quick identification of the status (armed or actuated) of the individual emergency stop button and optional indication of a machine or system stop have been disclosed. The illumination feature of the pushbutton-type device according to certain aspects of the present disclosure enhances the ability to comply with the requirements to clearly identify emergency stop pushbutton device and for it to be clearly visible. The exemplary switches and combinations of switches facilitate high visibility, easy access and convenient safety system configuration.

Because many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.

Claims

1. A switch, comprising: a housing comprising a substantially rounded cylindrical wall section;an electrical circuit enclosed in the housing and comprising a pair of electrical contacts and an illuminating device;an actuator adapted to be manually moved to open and close the pair of electrical contacts;the illuminating device being adapted to be set to different states of illumination at least in part depending on the operation of the actuator, and adapted to illuminate at least about a 50% circumferential portion of an exterior portion of the cylindrical wall section.

2. A switch, comprising: a housing;an electrical circuit enclosed in the housing and comprising a pair of electrical contacts and an illuminating device;an actuator adapted to be manually moved to open and close the pair of electrical contacts;the illuminating device comprising a substantially rounded cylindrical exterior portion, the illuminating device being adapted to be set to different states of illumination at least in part depending on the operation of the actuator, and adapted to illuminate at least about a 50% circumferential portion of the exterior portion.

3. The switch of claim 1, the illuminating device being adapted to illuminate substantially an entire circumferential portion of an exterior portion of the cylindrical wall section.

4. The switch of claim 2, the illuminating device being adapted to illuminate substantially an entire circumferential portion of the exterior portion.

5. The switch of claim 1, wherein the electrical circuit comprises a plurality of pairs of electrical contacts, and the actuator is adapted to be manually moved to open and close each of the plurality of pairs of electrical contacts.

6. The switch of claim 5, having an armed state, wherein at least a first one of the plurality of pairs of electrical contacts is closed and at least a second one of the plurality of pairs of electrical contacts is open in the armed state, and wherein the actuator is adapted to cause the first one of the plurality of pairs of electrical contacts to open, and the second one of the plurality of pairs of electrical contacts to close, upon a manual movement of the actuator.

7. A system, comprising a plurality of switches, each of which being a switch of claim 5, the plurality of switches being pairwise electrically connected to each other.

8. A system, comprising a plurality of switches, each of which being a switch of claim 6, the plurality of switches being pairwise electrically connected to each other.

9. The system of claim 7, the system further comprising a control unit electrically connected to at least one of the plurality of switches and adapted to detect whether a pair of contacts in the electrical circuit of each of the plurality of switches is open or closed.

10. The system of claim 7, the system further comprising a control unit electrically connected to at least one of the plurality of switches and adapted to control a state of illumination of the exterior portion of each of the plurality of switches.

11. A method, comprising: arranging the plurality of switches in the system of claim 7 in a plurality of respective locations;detecting a state of illumination of the exterior portion of each of the plurality of switches by machine vision.