Docente: Ing. Dante A. Salas

Manos y brazos aplastados, dedos seccionados, ceguera, la lista de posibles lesiones relacionadas con maquinaria es tan larga como horrible. Los protectores son esenciales para proteger a los trabajadores de lesiones innecesarias y evitables.

Una buena regla para recordar es: Cualquier parte o funcin de una mquina o proceso que pueda causar una lesin debe tener un protector.

Donde la operacin de una mquina puede lesionar al operario u otros trabajadores, el riesgo debe ser controlado o eliminado.

Causas de Accidentes con MquinasIntroducir las manos para liberar equipoNo sacar de servicio y etiquetarMantenimiento o uso de las mquinas por personas no autorizadas Protectores de la mquina sueltos o ausentes

Dnde Ocurren Riesgos MecnicosPunto de operacinTodas las partes mviles de la mquina tales como:Volantes, poleas, correas, acoplamientos, cadenas, manivelas, engranajes, etc .Mecanismos de alimentacin y partes auxiliares de la mquinaPuntos de mordeduras en movimiento

Punto de OperacinEl punto en el que se realiza el trabajo en el material: tal como cortado, modelado, agujereado o alisado debe estar protegido

Correa y PoleaCadena y Rueda DentadaCremallera y PinCilindros Rotativos

Requisitos para ProtectoresPrevenir el contacto impiden que el cuerpo y la ropa del trabajador tomen contacto con partes mviles peligrosasFijo Fijado firmemente a la mquina y que no sea fcil de quitarProteger de objetos en cada - asegura que no puedan caer objetos sobre partes en movimientoNo deben crear nuevos peligros - no deben tener puntos de corte, bordes dentados o superficies sin terminarNo deben crear interferencias - no deben impedir realizar la tarea rpida y cmodamente al trabajadorPermitir su lubricacin sin riesgos - si es posible, que la mquina se pueda lubricar sin quitar los protectores

Mtodos de Proteccin en el Uso de MquinasProtectoresfijosinterconectadosajustablesautoajustablesDispositivosdetectan presenciassacamanosde contencincontroles de seguridad (cable activador, control de dos manos, etc.)puertasUbicacin y distanciaMtodos de alimentacin y eyeccinalimentacin y eyeccin automtica y semi/automticarobotsAyuda con miscelneasbarreras que llaman la atencinescudos protectoresherramientas para alimentacin manual

Provee una barrera una parte permanente de la mquina; es preferible a todo otro tipo de proteccin.

Cuando este tipo de proteccin est abierta o es sacada, el mecanismo de activacin y/o encendido se interrumpe automticamente y la mquina no puede operar o encenderse hasta que se coloca la proteccin.Proteccin enclavada en tambor rotativo

Provee una barrera que puede ser ajustada para facilitar una variedad de operaciones de produccin.Proteccin ajustable en hoja de sierra

Provee una barrera que se mueve de acuerdo con el tamao de la pieza que ingresa al rea de peligro.Proteccin auto ajustable de sierra circular de mesa

Dispositivo SacamanosUtiliza una serie de cables adheridos a las manos, muecas y /o brazos del operarioUsado principalmente en mquinas con accin de golpeoPermite el acceso al punto de operacin cuando el elemento deslizante o el porta herramientas est levantado Retira las manos cuando el elemento deslizante/porta herramientas est levantado

Dispositivo Sacamanos (cont.)Manos en troquel, alimentandoPunto de operacin expuestoDispostivo sacamanos adherido y ajustado adecuadamenteTroquel cerradoManos retiradas del punto de operacin por el dispositivo sacamanos

Dispositivo de ContencinUsa cables o tiras adheridas a la manos del operador y a un punto fijoDebe estar ajustado para permitir que las manos del operador se desplacen dentro de un rea segura predeterminada Las herramientas de alimentacin manual a menudo son necesarias si la operacin incluye colocar material en el rea de peligro

Cables del Activador de SeguridadDispositivo ubicado en torno del permetro o cerca del rea de peligroEl operador debe poder alcanzar el cable para detener la mquina

Control de Dos ManosRequiere presin constante, concurrente para activar la mquina Las manos del operador tienen que estar en un lugar seguro (en los botones de control) y a distancia segura del rea de peligro mientras la mquina completa su ciclo de cerrado.

PuertaDispositivo de barrera mvil que protege al operador en el punto de operacin antes de que pueda iniciarse el ciclo de la mquinaSi la puerta no cierra completamente, la mquina no funcionaPuerta abiertaPuerta cerrada

Proteccin por distancia o ubicacinUbican la mquina o sus partes mviles peligrosas de modo que no sean accesibles o no presenten un riesgo para un trabajador durante la operacin normalMantiene una distancia segura del rea de peligro

Proteccin de encierro transparenteRollo de alimentacin de materialrea de PeligroTrabajo terminado

RobotsSon mquinas que cargan y descargan material, arman partes, transfieren objetos o realizan otras tareas.

Tienen su mejor uso en procesos de gran produccin que requieren rutinas repetidas en las que evitan otros riesgos para los empleados

No ofrece proteccin completa para riesgos de mquinas, pero s protege de partculas voladoras, salpicaduras de aceites de corte o refrigerantes.

Herramientas de AgarreUtilizadas para colocar y sacar material en reas de peligroNo se deben utilizar en lugar de otros protectores sino como suplemento

Algunos Ejemplos de Requisitos de de OSHA para los Protectores de Mquinas

Cuando la periferia de las aspas de un ventilador est a menos de 7 pies sobre el suelo o trabaja a nivel, las aspas deben tener proteccin con aberturas de no ms de pulgada.

Los apoya manos en mquinas de esmerilar deben mantenerse ajustados cerca de la rueda con una abertura mxima de 1/8 de pulgada para prevenir que la pieza trabajada quede trabada entre la rueda y el apoyo, lo que podra producir la rotura de la rueda.

La distancia entre la periferia de la rueda y la lengeta ajustable nunca debe ser ms de de pulgada .

Un aparato de transmisin de fuerza (rbol, ruedas, poleas, correas, cadenas de transmisin, etc.) a menos de 7 pies del suelo o la plataforma de trabajo debe tener protector.Correa y polea sin proteccin

Responsabilidades por la Seguridad en el Uso de MquinasDireccin de la empresaAsegurarse de que todas las mquinas tienen proteccin adecuadaSupervisoresentrenar a los empleados en las reglas de proteccin especficas de su reaasegurarse de que los protectores de las mquinas estn en su lugar y funcionan biencorregir inmediatamente deficiencias de protectores de mquinasEmpleadosno quitar los protectores a menos que la mquina est apagada y etiquetadainformar inmediatamente los problemas con protectores de mquinas a los supervisores no operar equipo a menos que tengan colocados los protectores

Entrenamiento Riesgos asociados con mquinas especficasCmo los protectores dan proteccin y los riesgos para los que fueron colocadosCmo y por qu usar protectores Cmo y cundo pueden quitarse los protectores y quin debe hacerloQu hacer si un protector est daado, falta o no da la proteccin adecuadaLos operadores deben recibir entrenamiento en lo siguiente:

En ConclusionLos protectores son esenciales para proteger a los trabajadores de lesiones innecesarias y evitables relacionadas con el uso de mquinasEl punto de operacin, as como todas las partes de la mquina que se mueven mientras la mquina funciona, deben estar protegidosUna buena regla para recordar es: Cualquier parte, funcin o proceso de una mquina que pueda causar lesiones debe tener proteccin

Per pas minero por excelencia

*This material was translated under Susan B. Harwood grant number 46F1-HT18 awarded to the Texas Engineering Extension Service, OSHA Training Institute Southwest Education Center from the Occupational Safety and Health Administration, U.S. Department of Labor. It does not necessarily reflect the views or policies of the U.S. Department of Labor, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. Este material fue traducido bajo nmero 46F1-HT18 de la concesin de Susan B. Harwood concedido a Texas Engineering Extension Service, OSHA Training Institute Southwest Education Center del Occupational Safety and Health Administration, U.S. Department of Labor. No refleja necesariamente las vistas o las polticas del U.S. Department of Labor, ni menciona los nombres comerciales, productos comerciales, o las organizaciones implican el endoso por el gobierno de Estados Unidos.

This presentation is designed to assist trainers conducting OSHA 10-hour General Industry outreach training for workers. Since workers are the target audience, this presentation emphasizes hazard identification, avoidance, and control not standards. No attempt has been made to treat the topic exhaustively. It is essential that trainers tailor their presentations to the needs and understanding of their audience.

This presentation is not a substitute for any of the provisions of the Occupational Safety and Health Act of 1970 or for any standards issued by the U.S. Department of Labor. Mention of trade names, commercial products, or organizations does not imply endorsement by the U.S. Department of Labor.

*29 CFR 1910, Subpart O**All parts of the machine which move while the machine is working can cause mechanical hazards. These can include reciprocating, rotating, and transverse moving parts, as well as feed mechanisms and auxiliary parts of the machine.*1910.212(a)(3)(i) & (ii)**In-running nip point hazards are caused by the rotating parts on machinery. There are three main types of in-running nips.

Parts can rotate in opposite directions while their axes are parallel to each other. These parts may be in contact (producing a nip point) or in close proximity to each other (where the stock fed between the rolls produces the nip points). This danger is common on machinery with intermeshing gears and rotating cylinders.

Another type of nip point is created between rotating and tangentially moving parts; for example, a chain and a sprocket, a rack and pinion, or the point of contact between a power transmission belt and its pulley.

Nip points can also occur between rotating and fixed parts which create a shearing, crushing, or abrading action; for example, spoked handwheels or flywheels, screw conveyors, or the periphery of an abrasive wheel and an incorrectly adjusted work rest.*Prevent Contact - A good safeguarding system eliminates the possibility of the operator or other workers placing parts of their bodies near hazardous moving parts.Secure - A safeguard that can easily be made ineffective is no safeguard at all. Guards and safety devices should be made of durable material that will withstand the conditions of normal use and be firmly secured to the machine.Protect from falling objects - A small tool which is dropped into a cycling machine could easily become a projectile that could strike and injure someone.Create no new hazards - A safeguard defeats its own purpose if it creates a hazard of its own such as a shear point, a jagged edge, or an unfinished surface which can cause a laceration. The edges of guards, for instance, should be rolled or bolted in such a way that they eliminate sharp edges.Create no interference - Any safeguard which impedes a worker from performing a job quickly and comfortably might soon be overridden or disregarded. Proper safeguarding can actually enhance efficiency since it can relieve the workers apprehensions about injury.Allow safe lubrication - Locating oil reservoirs outside the guard, with a line leading to the lubrication point, will reduce the need for the worker to enter the hazardous area.

**1910.212(a)(2)

As a general rule, power-transmission apparatus is best protected by fixed guards that enclose the danger area. For hazards at the point of operation, where moving parts actually perform work on stock, several kinds of safeguarding are possible.

*An interlocked guard may use electrical, mechanical, hydraulic, or pneumatic power or any combination of these. Interlocks should not prevent inching by remote control, if required. Replacing the guard should not automatically restart the machine.

*Adjustable guards are useful because they allow flexibility in accommodating various sizes of stock, but, because they require adjusting, they are subject to human error.*Self-adjusting guards avoid the potential for human error associated with adjustable guards.****Tripwire cables must be manually reset to restart the machine.*This kind of control requires a part-revolution clutch, brake, and brake monitor if used on a power press as shown.

A similar device, known as a two-hand trip, requires concurrent application of both of the operators control buttons to activate the machine cycle, after which the hands are free. This device is used with machines equipped with full-revolution clutches. The trips must be placed far enough from the point of operation to make it impossible for the operators to move their hands from the trip buttons or handles into the point of operation before the first half of the cycle is completed to prevent them from being accidentally placed in the danger area prior to the slide/ram or blade reaching the full down position. *Another potential application of this type of device is where the gate is a component of a perimeter safeguarding system. Here the gate may provide protection not only to the operator but to pedestrian traffic as well.*One approach to safeguarding by location is shown in this photo. Operator controls may be located at a safe distance from the machine if there is no reason for the operator to tend it.

Another approach is to locate the machine so that a plant design feature, such as a wall, protects the worker and other personnel. Enclosure walls or fences can also restrict access to machines. Another possible solution is to have dangerous parts located high enough to be out of the normal reach of any worker.

*Many feeding and ejection methods do not require operators to place their hands in the danger area. In some cases, no operator involvement is necessary after the machine is set up. In other situations, operators can manually feed the stock with the assistance of a feeding mechanism. Properly designed ejection methods do not require operator involvement after the machine starts to function.

Using feeding and ejection methods does not eliminate the need for safeguarding. Guards and other devices must be used wherever they are necessary to provide protection from hazards.

Automatic feeds reduce the operator exposure during the work process, and sometimes do not require any effort by the operator after the machine is set up and running.

The power press shown in the photo above has an automatic feeding mechanism. Notice the transparent fixed enclosure guard at the danger area.*Robots may create hazards themselves. If they do, appropriate guards must be used. The most common technique is to use perimeter guarding with interlocked gates.

The American National Standards Institute (ANSI) safety standard for industrial robots, ANSI/RIA R15.06-1999, presents certain basic requirements for protecting the worker. However, when a robot is used in a workplace, the employer should accomplish a comprehensive operational safety and health hazard analysis and then implement an effective safeguarding system which is fully responsive to the situation. [Various effective safeguarding techniques are described in ANSI B11.19-1990 (R1997).]

Studies in Sweden and Japan indicate that many robot accidents did not occur under normal operating conditions, but rather during programming, program touch-up, maintenance, repair, testing, setup, or adjustment. During these operations, workers may temporarily be within the robots working envelope where unintended operation could result in injuries.*Miscellaneous aids, such as these, do not give complete protection from machine hazards, but may provide the operator with an extra margin of safety. *1910.212(a)(3)(iii)**1910.212(a)(5)*1910.215(a)(4)*1910.215(b)(9)*1910.219***For more information on this subject, see the following OSHA publication available at www.osha.gov:

Concepts and Techniques of Machine Guarding OSHA 3067