Hammer chucks for rotary hammers: what they are and how they can be repaired

What are the cartridges for the torch and how to repair them?

It is difficult to imagine the processing of concrete without such an electric tool, as a peorator. It can be used not only for concrete drilling, but it is also an excellent tool for drilling holes in metal, plastic, wood, and other structures. To do this, you will need to insert the appropriate nozzles into the tool retainer. Exactly how a chuck for a peorator is designed, what kinds of them there are and how they differ is described in detail in this article.

Even children know what a peorator is. In order for this tool to perform the necessary useful work, it is necessary to install a nozzle in the design of the executive unit, i.e. a chuck. Unlike a drill, the electric tool is not only capable of rotary but also reciprocating (percussive) motions. The percussion motion is needed to resolve tough types of materials such as concrete and reinforced concrete.

The drill chuck serves to secure the attachment and to perform the necessary manipulations with the tool. Whereas drills use collet clamping devices, the torches use only mechanisms with a special design. Thanks to this particular design, the torch is much more efficient in working on concrete substrates. Drill chucks and lever chucks are virtually identical in appearance. The collet mechanism of the drill consists of three jaws that are pressed together uniformly by the rotational force, thereby clamping a cylindrical nozzle structure securely. Read on to find out how chucks on rotary tools are constructed.

Dismantle the chuck or replace it with a new one?

Breakage of a peorator cartridge is rare, but always unfortunate. Good thing that a fault on this part can easily be repaired on your own. But you need to know how it works.

The cartridge

All electric rotary tools are equipped with simple and reliable SDS chucks. Their prototype was designed by engineers of West German company Bosch. Therefore, the abbreviation in the name is formed from the German words: Steck, Dreh, Sitzt. Which in this case means “insert”, “turn”, “sit”. Now five modifications of this design are made:

• SDS. For bits with 10mm Ø shank that has two longitudinal slots to prevent twisting. Shank insertion depth of 40 mm. This construction perfectly matches the tools having the SDS-plus shank.
• SDS-plus. Leader in frequency of use among peorator cartridges. Designed for bits with 10mm Ø shank with four slots (two long ones to prevent rotation and two shorter ones to prevent bits from falling out). Insertion depth of 40 mm. This type is used on lightweight peorators. It can work with nozzles Ø 4-32 mm, length from 11 cm to 1 m.
• SDS-top. Rarely seen type. Fitted on medium-sized rotary axes. Its bit has a Ø 14 mm shank with two long and two short grooves. Fitting depth 70 mm, with a maximum auger diameter of 32 mm.
• SDS-max. Occurs only slightly less often on torches than the leader. Designed for drills with a diameter larger than 2 cm. Primarily used with heavy torches. Its shank Ø 18 mm is inserted by 9 cm and has three long and two short slots.
• SDS-quick. This type is designed for hexagonal quarter-inch shank instead of slots, equipped with projections. Can even hold drills and bits. Prior to 2009. exclusively for Bosch Uneo. The drills for it do not make thicker than 1 cm.
• SDS-hex. Only spades and chisels have shanks for use with it. And it is only for demolition hammers.

The drill chuck design is not the same as the electric drill chuck. The drill chuck grips the drill bit with movable jaws. The auger is secured against turning in the peorator by means of the guides entering into the slots in the shank. It is prevented from falling out by a latch made of spring-loaded balls. To fix the core bit, slide the drill bit shank into the hole in the drill bit. And by pushing the nozzle in, you can push it in until it clicks. Pull the plastic jacket to remove the auger.

Replacing the chuck

If you do not have a drawing, take a picture of the disassembling process with your phone. This will save you from making a mistake when reassembling. You will need the following tools for the job: a flat screwdriver, long-jaw pliers, a hammer and a wrench.

• Remove the rubber tip from the end.
• Pick up with a screwdriver and remove the first circlip.
• Pull the plastic sleeve cover downward (as for changing the drill bit).
• Remove the second retaining ring in the same manner as the first.
• Remove the coupling guard.
• Remove the spring, retainer plates and balls.
• If you can do without replacing the whole assembly, then put the steel parts in a suitable container and fill it with kerosene.

The chuck is fastened to the spindle normally by means of a thread. Clamp it with a vice or wrench. Use an open-ended wrench to turn the spindle. If there are no faces, then disassemble the housing, fix the spindle and rotate the chuck.

Carefully. Do not put the tip in kerosene. Since its rubber is not oil-resistant, it will not withstand long contact with it.

Reassemble and reassemble the assembly in reverse order.

Drill bit does not lock in place

There can be several reasons why the chuck does not hold the drill bit shank. The most likely causes are as follows.

• Wear of the body, retaining plates or balls.
• Retainer spring is loose or broken.
• Dried out or thickened grease from dirt, preventing movement of the retainer balls.

Important. Do not lubricate parts with petroleum jelly during assembly. It is only used in the preservation phase. Among greases, lithol is the best.

Repair or Replace

If you don’t have the parts, chuck repair will only be easy in two cases:

• When the balls wear out.
• And when the grease, having lost its plasticity, prevents the parts from moving. In other cases, it is easier to find a replacement unit than to repair it.

Constructional Features

Many people want to know what the SDS chuck on rotary screwdriver is all about.

• The jaws used on collet devices have been replaced by splines. Also splines are often called rails. Plus there are retainers used here, represented by rollers and balls.
• Slots in the mechanism are used to center the bit that is being fitted. Slots also help ensure that the bit rotates with the chuck.
• Depending on the device, balls or rollers can be used. But they have the same function. It prevents the bit from possibly falling out of the chuck. This locking principle allows the auger to move, which is of key importance when drilling high-strength concrete or reinforced concrete structures.

To better understand the internal construction of the chuck, it is worth looking at the shank of peorator bits.

There are recessed areas (grooves) on the nozzle. For SDS-Plus, 4 slots are provided: 2 open and 2 closed. Due to the open grooves, the drill bit clings to the slots and the closed grooves are connected to the ball inside the retainer.

As for the design itself, the chuck consists of several elements:

• The axle in the form of a sleeve with slots;
• ring slotted on the sleeve (spring mechanism acts on the ring);
• Retaining balls, which are located between the sleeve and the rings;
• protective cover (sheath).

This chuck is a quick-action chuck. It works according to the following principle

• the nozzle is inserted into the hole;
• To insert the chuck into the chuck, you have to push the device by pressing it;
• In this case the springs and washers begin to shrink;
• The ball goes aside and the shank sits in its place;
• A “click” when you let go of the cover tells you that the bit has engaged successfully.

You can check if the fixation is secure by trying to pull the nozzle out of the hole. The bit may move inside the chuck, but it will not fall out.

The chuck is called a “quick-action chuck” or a “quick-release chuck. The point is that the part is also rather quick to remove. It is enough to press on the cover, which disengages the element and remove the nozzle.

How to insert the cartridge into the chuck

To insert the chuck into the torch, screw the drill all the way in, insert it into the socket and screw it in using a screwdriver.

Experts recommend to have a spare chuck always at hand. You should not economize on this element. At the time of purchase it is desirable to have your peorator, then it will be easier to choose the necessary part, because not all models of peorator and chucks fit each other.

Types of chucks for the torch chuck

Different types of chucks can be used in these chucks. Each has its own differences.

Toothed toothed

It’s also called a key chuck. This variety allows the attachment of a screwdriver bit that has a cylindrical shank. It is fastened using a special slotted wrench. They are used to move the cams, which securely clamp the tool. The toothed-ring chuck has the advantage of safe clamping of tools with cylindrical and hexagonal shank parts. But it takes a long time to fit or remove a drill bit in these chucks.

Quick-clamp

Quick-action chucks are mostly used in screwdriver construction. There are one-coupling and two-coupling chucks. They are fixed in the same way as key chucks, only without using a wrench, everything is done manually. Double clutch chucks provide a more secure hold. But since clamping is done by hand, the workpiece can be safely clamped. The fixing is inferior to a wrench in terms of reliability.

The disadvantage of the quick-clamping element is that it does not reliably hold drills with large diameters when used for extended periods of time. As a result, the tool turns during drilling, which negatively affects the quality and speed of the work.

This type is considered the best option for peorators, although it appeared not so long ago. SDS cartridges are often called “quick-release cartridges. They are suitable for drilling in concrete, wood and metal. But their clamping equipment comes in different types, so you need to know their features.

Equipped with several types of clamping devices :

• Plus. Tail part for the chuck of a tool designed for home use.
• Top and Quick. Very rarely used. It is not easy to buy bits for installation in these types of chucks. Few companies manufacture them. That’s why you should look at the modification of the retainer when you buy it.
• Max. these parts are only used in specialised models of rotary tools.

The gator chuck securely holds the drills. Locking is done with 2 guide wedges and 2 locking balls. The advantages of SDS chucks are that it is easy and safe to work with the clamping device. torque and impact force are perfectly combined. 90% of all rotary tools produced are equipped with these easy-to-use features.

Secure locking of the shank is a guarantee of efficient and high-quality work.

Switching of gears

For normal use of the tool, you must learn that there are several modes of operation:

• The first of these is drilling. During work in this mode, you must:

• toggle the tumbler for selecting modes opposite the drill marking;
• Then insert the drill and switch on the power tool.

If you don’t know how to insert the drill bit into the rotary table, we can tell you.

To fit the core bit into the cam or collet device, simply push the drill bit into the device. Then put the spanner in the hole on the outside of the chuck and turn it until the auger is completely clamped.

Do not exert too much pressure on the bit during work.

Tip: When using the chuck in drilling mode, never switch the toggle switch to “counterclockwise rotation”, as this could damage the bit.

Locking function on the rotary tool to prevent impact. It is generally used for drilling holes in wood or metal construction.

It is advisable to let the machine idle for a few minutes before inserting the drill bit into the chuck. Be sure to check the gearbox. It should not make a noise or knock. If not, have it repaired.

Keep a close eye on the auger during work:

Remember that when drilling in concrete you can bump into pieces of reinforcement, so take a comfortable position beforehand so that you do not lose control of the tool.

Before you start your work, first turn the rotary switch to the symbol of the hammer. Remember that the tool must be held very firmly in this mode.

Tip: Move the power tool to the point you want to hit before you switch it on.

Peorator chuck: design, replacement, repair

Every tool is subject to wear and tear and the torch is no exception. One of the common breakdowns of the peorator is a malfunction of the clamping chuck. The tool bits may not fit properly and sometimes cannot be removed. This is most likely to occur if the tool is not properly maintained. Although the design of the chuck is quite complex, its repair or replacement is quite feasible for the home handyman.

How the Peorator Chuck Works

Modern peorator chuck has the SDS design. This abbreviation stands for the words Steck, Dreh, Sitz. This translates as “put in, turn, clamp”. This is the order in which the bits are inserted in the rotary tool. It does not matter if it is a drill bit, a pick, or a drill adapter. The most common chuck types:

Both types enable tool bits to be changed quickly.

SDS-plus

Lightweight rotary hammers designed for drilling holes up to 20 mm in diameter in concrete or masonry have this design. There are four slots in the shank of the bit. Grooves (4) guide the movement of the bit when inserting it; they are in contact with the chuck wedges (5) and so ensure the rotation of the working tool. The slots (2) serve to secure the drill shank and contain the retaining balls, preventing the augers from popping out.

SDS-max

SDS-max is used on heavy rotary tools. These tools have a powerful motor with high impact force. They are used to make holes up to 50 mm. grooves in the tool to reduce the loss of torque. Otherwise designed similar to SDS-plus.

Other chucks

Except SDS, there are less common clamping designs. They are designed for holding tools with a smooth shank.

Keyhole chuck for peorator, a.k.a. toothed-ring chuck, is similar to the standard drill clamp. The tool is fixed in it by three cams, which are moved by the influence of a special key. Although the bit is firmly held, its use is limited because tool changes are quite time-consuming.

Quick-action chuck designs are more convenient to use, save time on accessory changes. With the double-clutch chuck, in order to clamp or release the working tool, you have to hold the rear part and rotate the front part, i.e. both hands are involved. The single-coupling design allows for one-handed operation, but requires locking the work shaft. This option must be incorporated into the design of the torque limiter.

Despite the convenience of quick-action chucks, the SDS design retains primacy.

Disassembly of the SDS cartridge

This assembly needs to be disassembled to evaluate the condition of the bent-iron sleeve. Begin disassembly by removing the front rubber dust cover. It is not fastened in any way, you just need to pry it up with a screwdriver.

Then the circlip and washer are removed. This is how the spring is released.

One must be very careful when removing the spring: there are retaining balls that can easily slip out and be lost. After removing the spring, the rear dust cover can be removed.

The cylinder is fastened by four inserts that simultaneously pass through the walls of the barrel. Inserts are flush in the walls, there’s nothing to grab them. To remove the inserts it is best to use a small magnet or a magnetized screwdriver. Slightly twist the freed chuck from side to side to remove it. After examining the chuck, they conclude whether it needs to be replaced in its entirety or only some of its parts. Reassemble in reverse order.

Frequent malfunctions of the clamping unit

The most common faults in the rotary chuck are.

• Dust cap is worn or cracked, allowing construction dust to penetrate the chuck and contaminate the lubricant and hinder rotation.
• Retaining ring. Its weakening releases the spring, the balls fall out of their grooves, the drills are not retained.
• Guide cylinder. Internal grooves are worn, making it impossible to reliably fix the drills.
• Spring. Its wear or breakage reduces the cushioning.
• Balls. A loss in diameter due to wear makes it impossible to retain the drill.

Balls, spring and snap ring can be replaced by other machined parts of appropriate dimensions, or try to make one yourself. The oil seals and guide cylinder cannot be repaired; they must be exchanged for original, serviceable parts.

All necessary parts are sold in specialized stores.

As you can understand, the repair of the peorator cartridge is not that complicated. After the end of the warranty period, if the tool breaks down, it can be repaired at home, without calling a service center.

How are the chucks for your rotary tool constructed?

To use the various bits and accessories for the rotary table effectively, they need to be clamped in place. This is what a special chuck is for. The first models began to be developed back in the 1930s, when the market saw the appearance of peorators, mass production of which was mastered by the world-famous company Bosch.

The manual device was immediately appreciated by users, because it makes it possible to combine drilling with pulse drilling, which significantly increases the effectiveness of the work performed. The main disadvantage of the first models of cutters was the fact that the weakest link in their design was the chuck, which quickly became unusable under the influence of shock loads.

As a result of long-term development, the manufacturers of torches and chucks have come to the following conclusion: the simpler the design of the clamping device, the more reliable it is in operation.

Externally the geared chuck is a completely closed chuck

Three main types of chucks for rotary tools were created, which in turn are divided into subtypes.

There are chucks in which the actuating cams actuate a special key that securely clamps the shank of the tool being used. The most important advantage of this type of chuck is that it is used to securely fasten the tool used in the scope of the geared tool. Meanwhile, in order to change the working tool in such a chuck for a peorator, it will take considerably more time than with other types of clamping devices.

Main chuck types for the rotary tool

The working chuck can also be fastened to the chuck by means of a quick-action chuck (QAJ), which can only be actuated by the force of the operator’s hands. Depending on their design, this type of chuck can have one or two clutches, which also have different operating principles.

Single clutch chucks are easier to use, but they can only be used in combination with drills that have an automatic shaft locking feature. One hand is sufficient to actuate this chuck. To use a double-clutch chuck it is necessary to hold the rear clutch with one hand and rotate the front clutch with the other.

Disassembling the SDS-plus chuck with bushing replacement

It is often necessary to replace the bush, on which the chuck of the torch is held. To do this, you must disassemble by removing the dust cover, retaining and thrust rings, remove the ball and spring and remove the plastic cover. After that, the rollers and the bushing of the cartridge can be removed. The bushing consists of the cartridge body, the striker bolt and the striker bolt guide, if necessary it can be replaced with a new one, or the component parts can be replaced.

Sometimes you can see a situation where there is an interchangeable quick-action drill chuck on the SDS-plus adapter in the main socket of the peorator. If it can not be removed as a result of a failure, it can be difficult to disassemble and replace the chuck. It will not be possible to remove the rings and shroud, remove the spring, because the dimensions of the quick-action chuck will not allow to do it. That is why you must first remove the quick-action chuck from the pen.

At first, the quick-clamping nozzle is loosened, and inside it you can see a screw with grooves for a screwdriver. It is unscrewed and removed to the adapter SDS. After that it is possible to disassemble the chuck of the peorator.