拉绳开关WST-K212/L-S2 （10A IP66 两开两闭）俗称紧急停机开关。作用于带式输送机现场需要停机时，通过开关动作使输送机停机。双向拉绳开关广泛用于钢铁、水泥厂、电厂矿山等具有带式输送机的矿厂，该产品安装在胶带输送机两侧，是用于胶带输送机紧急事故的一种保护开关，在开关操作距离内任何一点拉动钢丝绳，切断运行电路使全线停机，实现对胶带机及人身安全的保护，它分手动型和自动型，手动型动作后自销，并有警示牌显示，须手动复位。自动型自动复位，当紧急事故发生时任意拉动拉绳传感气即可停机。
拉绳开关WST-K212/L-S2 （10A IP66 两开两闭）采用不锈钢双轴承传动结构避免了开关动作时传动轴直接摩擦壳体或轴套，造成间隙增大，出现密封不严或者卡死的情况，大幅延长拉绳开关使用寿命;壳体表面精工烤漆，不易脱落无异味；传动轴采用不锈钢材质强度高，表面光滑；操作杆精铸成型，避免焊接，内置铜质衬套，整体光洁强度高等等。本开关具有寿命长、灵活实用、安全可靠、检修方便等特点。当维修人员没有撤离或尚存在其它异常情况时，只要将拉绳开关锁定在停机位置，就不用担心胶带机被误启动，维修人员的安全也就有了保障。
安装和调整
拉绳开关应安装在输送机两边具有检修通道的地方，安装位置应确保检修人员在紧急情况下操作方便。
1、将拉绳开关固定在机架上。
2、一侧的两台开关之间距离为50m左右，采用直径为Φ4的钢丝绳连接，松紧应适度。
3、为减小钢丝绳自重对开关启动的影响，每隔3m在机架上装一个托环，以支撑钢丝绳。
4、钢丝绳的另一端系在拉簧上(用绳扣固定),在不影响正常使用下用紧线器将两侧拉绳张紧,并确保两侧张力均衡。
（注:对于爬坡段输送机机.应尽量缩短开关间距及拉绳长度。）
工作原理:当胶带运输机现场紧急事故时，在沿线任意位置牵动系在挂耳上的钢丝绳，迫使机内凸轮转动而驱动元件开关动作，发出停机信号，达到停机效果，防止事故的扩大。
结构特点:
1．本产品采用铝合金铸造壳体、强度高、重量轻。
2．外壳防护等级达到IP65，可在恶劣环境下长期工作。
3．本产品动作灵敏、稳定性高、性能可靠。
主要组成部分
双向拉绳开关主要是由拉杆、凸轮、复位柄、锁槽、微动开关等部件组成。拉绳开关安装于皮带式输送机两侧机架之上，采用钢丝绳沿着输送机设备两侧将开关连接起来。在输送带设备发生紧急事故情况下时，在输送机沿线任意处拉动钢丝绳，钢丝绳将会牵动驱动臂开始旋转，通过传动轴从而带动扭力弹簧使精密的凸轮发生位移，驱动双向拉绳开关切断控制线路，使得输送机快速的停止运行。
电气参数:
电压通用:24V-48V-220V-380V-480V,
电流通用:1A，2A、3A、4A、5A、6A、7A、8A、9A、10A.15A
拉绳开关分为手动复位和自动复位两种，需要达到国家规定IP等级。
拉绳开关WST-K212/L-S2 （10A IP66 两开两闭）广泛用于冶金、煤炭、水泥、采矿、电力、港埠、化工等领域的各种专门从事散料输送的输送设备。
The pull rope switch wst-k212 / l-s2 (10A IP66) is commonly known as emergency stop switch. The conveyor will be shut down by the switch action when it needs to stop at the site of belt conveyor. Two-way stretching wire switch is widely used in iron and steel, cement plants, power plants, mining, etc have mine belt conveyor, the product is installed on both sides of belt conveyor, is a kind of protection to the belt conveyor emergency switch, the switch operating range any pull rope, cut off the circuit operation makes all downtime, realize the tape machine and personal safety protection, it split type and automatic type, manual type movement after another, and there are warning signs show that must be manually reset. Automatic automatic reset, when the emergency occurs, any pull rope sensor can be stopped.
Rope switch WST - K212 / L - S2 (10 a IP66 two open and closed) stainless steel double bearing transmission structure to avoid the friction drive shaft directly in the switch action shell or shaft sleeve, cause clearance increases, appear untight seal or jammed, significantly prolong the service life of the rope switch; Shell surface finish work baking varnish, not easy to shed no smell; The transmission shaft is made of stainless steel with high strength and smooth surface. The operation rod is made of precision casting, avoiding welding, built-in copper bushing, high integrity and so on. This switch has the characteristics of long life, flexible and practical, safe and reliable, easy to repair and so on. When maintenance personnel is no withdrawal or other abnormal situation, as long as will pull on the rope switch is locked in the down position, will not have to worry about the adhesive tape machine was false starts, the safety of the maintenance personnel also have the guarantee.
Installation and adjustment
The pull cord switch should be installed on both sides of the conveyor to have access to the access channel. The installation position should ensure that the maintenance personnel operate in an emergency.
1. Attach the pull rope switch to the rack.
2, two on one side of the switch is about 50 m, the distance between the diameter of Φ 4 wire connection, elastic should be moderate.
3. In order to reduce the influence of the self-weight of the wire rope on the switch startup, every 3m is equipped with a supporting ring on the rack to support the steel wire rope.
4. The other end of the wire rope is attached to the tension spring (fixed with the rope), and the two sides of the rope are tensioned with a tight wire without affecting normal use, and the tension balance on both sides is ensured.
(note: for the climbing stage conveyor machine. The switch spacing and length should be shortened as far as possible.)
Working principle: when the belt conveyor at the scene of accident and emergency, in any position along the affects system of wire rope on the hangers, forcing machines CAM rotation and motion switch driving element, signal down, get down effect, prevent accident expanding.
Structural features:
1. This product adopts aluminum alloy casting shell, high strength and light weight.
2. The enclosure protection level is up to IP65, which can work in a bad environment for a long time.
3. This product is sensitive to action, high stability and reliable performance.
Main component
The two - way pull - rope switch is mainly composed of pull rod, CAM, reset handle, slot, micro - switch and so on. The pull cord switch is mounted on the rack on both sides of the belt conveyor, and the wire rope is used to connect the switch on both sides of the conveyor. In conveyor equipment emergency accident cases, at any position along the conveyor pull wire rope, wire rope will affect driving arm begins to spin, through the drive shaft to drive the torsion spring displacement in the precision of the CAM, drive the two-way stretching wire switch to cut off the control circuit, makes the conveyor quickly stop running.
Electrical parameters:
Voltage: 24V-48V-220V-380V-480V,
Current general: 1A, 2A, 3A, 4A, 5A, 6A, 7A, 8A, 9A, 10a.15a.
The pull rope switch is divided into manual reset and automatic reset, which needs to reach the national IP level.
It is widely used in metallurgy, coal, cement, mining, electric power, port and chemical industries, etc., which is widely used in bulk conveying equipment.