Machine Guards: Types: Applications, Benefits, and Design

Machine guards play an essential role in ensuring the safety of workers and the efficient operation of machinery. They protect individuals from exposure to hazardous parts, flying debris, and other potential risks associated with operating industrial machines. This article delves into the various types of machine guards, their applications, benefits, and design considerations.

Types of Machine Guards

Chuck Machine Guards

Chuck guards are safety components that protect workers from excess shards, shavings, material chips, and tool bits that may fly away from working machinery and injure them. They are simply curved pieces of material attached to the machines with a bracket and screws. Chuck guards are most commonly found on lathes, which spin at high RPMs (revolutions per minute) to shape metal, wood, and glass products. Chucks, which are clamping components used to grip rotating materials and tools in place, are commonly used on lathes. All chuck guards are joined to the chuck to facilitate access to the lathe and can be swung or lifted away.

Chuck guards are commonly used in factories and manufacturing facilities to protect workers in areas where glass blowing, metal spinning, shearing, and sanding operations take place. Chuck guards, in addition to protective clothing and goggles, should be purchased to prevent workers from being hit or cut by debris flying off the lathe, which is spinning at a very high RPM. While the debris is usually small, it moves at high velocities and is thus considered hazardous to workers. Chuck guards are simple and efficient answers to the hazards of lathe work. If you want to know more details, see more details.

Drill Press Guards

Drill press guards protect machine operators from avoidable injuries while they operate drill presses. Drill press guards protect plant operating personnel from contaminants, moving parts, flying debris, and noise caused by drill presses.

Drill press guards, a subcategory of machine guards, shield operators' eyes and hands from cutting blades, cutting tools, hot chips, grease, splash coolants, and oil. Drill presses, according to the OSHA list, need guarding where work is done when the material is in an ongoing process. Drill press guards come in a variety of styles.

Fixed Machine Guards

A fixed machine guard is permanently joined to the tool or machine, has no moving parts, and can’t be moved while the machine is under operation. They are most commonly used to cover the point of operation or other hazards with which the operator does not need to interact with, such as flywheels or fan blades. Because fixed machine guards are permanent features of the machinery, they have to be taken apart and removed before any type of adjustment or maintenance can be performed.

Interlocked Machine Guards

When an interlocking guard, also known as a barrier guard, is opened or removed, the power source is automatically turned off or disengaged. These are especially useful when operators want to be able to open the guards or access the machinery’s guarded parts, like when clearing jams.

These guards permit safe access to the machine's interior without requiring total disassembly. They can, however, be easily opened by accident and need care and maintenance adjustment.

Lathe Machine Guards

A lathe guard is a visor or shield that serves as a point-of-operation protective barrier for operators and workers when they are near a spinning lathe. They prevent injuries or accidents caused by flying chips, debris, broken tool bits, and shavings. Lathe guards also keep fingers away from the spinning lathe, which spins at a high RPM (revolutions per minute).

Lathe guards come in pre-engineered sizes or are custom made to fit the particular dimensions of the machine. They are easily attached to the chuck or cross-slide by a bracket on screws, though others are attached to other lathe devices. Lathe guards can be curved and thus shaped as a half circle, or they can be flat and have three sides. The most common design consists of an aluminum die-cast frame and a big polycarbonate vision panel, a see-through plastic material which behaves like glass but is lightweight, has high impact strength, shatter resistance, and flexibility.

Milling Machine Guards

Milling machine guards are three or two-sided covers that enclose dangerous milling machinery. They also shield operators and machinists from flying coolant, swarf, tool breakages, and detached material pieces. Milling machine guards also keep the workplace clean and workers safe without sacrificing productivity.

Milling machine guards are a structure of panels in an aluminum frame or steel tubing, and they are always made of transparent panels to allow workers to see the fabrication process. Milling machines are tools used to shape and shape solid materials such as wood, plastic, and various metals.

They are mostly found in manufacturing facilities, but they are also seen in workshops and school shop classes. When the milling machine is in use, all machine guards are secure and locked, regardless of their design; static, which is non-moving, or traversing, which can move without being detached. Milling machine guards are either pre-engineered in a variety of sizes or handcrafted to precise design specifications. Their size varies according to the dimensions of the milling machinery, but they are typically bigger than other machine guarding parts.

Milling machine guards are classified into two types: sliding guards and stationary guards. To protect workers, both are locked in place always while the milling machinery is in operation, but some can slide back and forth along a cross-slide, whereas others must be detached but can be swung out of place to access the machining area. All milling machine guard panels are see-through and made of polycarbonate, a resistant, shatterproof, and strong plastic material.

Safety Barriers

In industrial uses, safety barriers are physical compartments that prevent accidents and injury. They keep operating personnel and employees away from potentially hazardous machines, keep vehicles away from restricted areas, and control traffic. They house robotic and automated systems, heavy machines that could cause injury, and racks and shelving systems.

There are two kinds of safety barriers that protect from physical injuries from workers engaging with dangerous machines and costly vehicle caused accidents. Wire mesh and fencing barriers, for example, keep unauthorized persons from accessing prohibited areas and completely cover dangerous automated machines. These systems frequently have electrical doors with interlocks which shut down when they are opened. They are typically higher than six feet, simple to assemble, and installed with a sequence of posts mounted to the ground. The doors can be panel or swing, which is just one facet of the barrier that can be customized to meet the company’s requirements.

Safety Guards

Safety guards are physical barriers built around potentially hazardous machines and mobile parts. Safety guards come in a variety of sizes and shapes and are intended to protect employees from any avoidable injuries associated with the operation of machines. Many safety guards are custom-made to meet the safety requirements of a specific mechanism or device. Metals, wood, and plastics are all common materials for safety guards. The material utilized is determined by the machinery from which the safety guard protects employees.

The types of safety guards are self-adjusting, adjustable, fixed, and interlocked. Self-adjusting guards can automatically adjust themselves, whereas conventional adjusting machine guards should be shifted by hand. Fixed guards are permanently affixed to a part of the machinery, whereas interlocked guards are by electronic means connected to the machinery and thus capable of shutting down the machine if the barrier is crossed.

Self Adjusting Machine Guards

When workers put new materials into the machines, self-adjusting machine guards adjust their positions automatically. They are also frequently used with saws. They shift away from the point of operation, opening up just enough to allow material into the cutting zone of a blade. When the blade is not in use, they enclose the other half of it.

Aside from these, a wide range of machine guards are designed to protect specific types of machines, such as chuck guards and lathe guards, drill press guards, milling machine guards, wire guards, brake monitors, and safety light curtains.

Wire Machine Guards

Wire guards direct traffic, demarcate security zones and prevent big flying debris from leaving the machinery workplace. They are simple and quick to install, and they are not affected by power cuts or electrical mishaps, as are safety light curtains. Wire guards are commonly used to protect robotic and automated machinery, heavy machinery, tanks, spiral HVAC fans, and motors. They are used both outdoors and indoors and are typically more than six feet tall to prevent people from climbing over the barrier.

Wire guards protect workers from accidents and injuries and prevent unapproved personnel from accessing certain work zones and reduce the risk of tampering and vandalism. Wire guards, unlike other types of machine guards, are an efficient way to warn workers about the presence of potentially dangerous machinery. They are frequently painted in bright colors such as yellow or orange, and warning signs are hung from them.

One of the most common, tiered guards fastens to the drill press's quill and encloses the rotating pieces of the press. Operators have a complete vision while drilling, ensuring that the product is not harmed due to safety precautions. Although they rarely cause problems, drill press guards can occasionally obstruct the task. A protocol for the task should be developed after assessing all potential safety hazards. After it has been applied, the guard may be removed, and the task is completed.

The types of safety guards are self-adjusting, adjustable, fixed, and interlocked. Self-adjusting guards can automatically adjust themselves, whereas conventional adjusting machine guards should be shifted by hand. Fixed guards are permanently affixed to a part of the machinery, whereas interlocked guards are by electronic means connected to the machinery and thus capable of shutting down the machine if the barrier is crossed.

Applications and Benefits of Machine Guards

This chapter will discuss the applications and benefits of machine guards.

Applications of Machine Guards

Presses, automated assembly line machinery, milling machines, roll form machines, saws, feeders, and robotics, to name a few, contain potentially hazardous components that must be protected by a machine guard in order to operate safely. Machine safeguards are critical for these machines because they avoid crushed hands or fingers, burning, blindness, limb loss, or death. Machines are frequently being made with integral machine guards, but some ought to be analyzed before the specific user-built guard may be applied at the point of operation. Machine guarding is also required for robots.

Benefits of Machine Guards

• Fixed Guards – They can be constructed to fit many specific applications. In-plant construction is often possible. Fixed guards offer maximum protection and usually need minimum maintenance. These guards also are suitable for repetitive, high production operations.
• Interlocked Guards – Interlocked guards provide maximum protection. These guards allow access to the machinery for fixing jams without lengthy removal of the fixed guards.
• Adjustable Guards - Adjustable guards can be constructed to fit many specific applications. It can be adjusted to allow ranging sizes of stock.
• Self-Adjusting Guards - Off the shelf guards are often available commercially.

Machine guards are immensely beneficial and necessary. They ensure the safety of workers, orderliness of operations, and efficient flow of work. Furthermore, by keeping workers safe, they instill confidence and well-being.

Drawbacks of Machine Guards

• Fixed Guards - Visibility may be interfered with. It may be limited to certain operations. Machine repair and adjustment often need its removal, hence requiring other means of protecting the maintenance personnel.
• Interlocked Guards - Need careful maintenance and adjustment. It may be easy to disengage.
• Adjustable Guards - Fingers may enter dangerous areas, protection may not be thorough at all times. May need frequent adjustment and maintenance. The guard may be made inefficient by the operator. Visibility may be interfered with.
• Self-Adjusting Guards - Self-adjusting guards do not always provide maximum protection and visibility may be interfered with. These guards may need frequent adjustment and maintenance.

OSHA Specifications for Machine Guards

The OSHA requirements for machine guards alludes to:

• 1910.212(a) (1) – Guarding types. One or several methods of machine guards shall be provided to protect the machine operator and other employees in the machinery area from dangers like those made by point of nip points that are ingoing, operation, spinning parts, sparks, and flying pieces. Examples of guarding methods are two-hand tripping, devices barrier guards, electronic safety devices, etc.
• 1910.212(a) (2) - Machine guards general requirements. Guards shall be attached to the machinery where possible and secured anywhere else if for any reason joining to the machine is impossible. The guard shall be in such a way that it will not offer an accident danger in itself.
• 1910.212(a) (3) - Point of operation guarding.
• 1910.212(a) (3) (i) - Point of operation is the place on machinery where work is carried out upon the material undergoing processing.
• 1910.212(a) (3) (ii) - Operation of machinery which exposes employees to injury, must be guarded. The guarding part will be in adherence with any appropriate safety standards thereof.
• 1910.212(a) (3) (iii) - Special tools for detaching and putting material will be such that they allow simple handling of materials without the machine operator placing his hand in a dangerous area.
• 1910.212 (a) (4) - Barrels, drums, and containers. Revolving barrels, containers, and drums shall be guarded by a cover which is interlocked with the drive device, so that the drum, container, or barrel cannot rotate unless the guard cover is in place.
• 1910.212 (a) (5) - Exposure of blades. When the margin of the fan blade is under seven feet over the working floor, the blades will be guarded. The guards shall have openings no bigger than one-half inch.

Machine Guards Maintenance

Guards must be inspected as part of the machine guard maintenance schedule.

A guard must be replaced in the event there are:

• Tearing or visible cracks or
• Dents from impact or bulges.
• Holes (unless put by the manufacturer or for mounting reasons)

Guards must be cleaned with a plastic cleaner which is non-abrasive. Guards must never be cleaned with cleaning products which are based on ammonia (like glass cleaner). Yellowing of transparent guards is not a primary concern as the guards are manufactured from PETG plastic and not polycarbonate.

Conclusion

A machine guard is a device whose role is to act as a safety barrier between a worker and machines used in manufacturing facilities, factories, plants, and warehouses. They are manufactured from extrusion, CNC machining, and post extrusion process. Metal is usually the preferred material for making machine guards though plastic and wood are used as well. Machine guards play a vital role in protecting operators and employees from workplace hazards.