Cordless drill-driver

How it works

An electric motor turns a spindle through a gear train, and the spindle carries a chuck that grips the bit. The trigger switch is variable: the farther it is squeezed, the faster the chuck turns. A forward and reverse button sets the direction of rotation, and in its center position it locks the trigger off. In the DEWALT manual for a 12 volt class model the chuck stops when the trigger is fully released, because the tool is equipped with a brake.

Two controls adapt the tool to drilling or driving. A gear shifter selects a low-speed, high-torque range or a high-speed, low-torque range. A numbered collar behind the chuck sets a clutch: the higher the number, the higher the torque and the larger the fastener that can be driven, and the drill-bit symbol locks the clutch for drilling. The manufacturer describes the numbers as locators that remove guesswork when selecting fastening torque.

The power source is a rechargeable battery pack. The chemistries used in these tools have changed from nickel-cadmium cells in Black & Decker’s 1961 drill, as the company describes it, to nickel-metal-hydride and then lithium-ion cells.

Anatomy

Chuck: Grips the bit. The manual describes a keyless single-sleeve chuck with an automatic spindle lock, so one hand can open and close it.
Torque adjustment collar: The numbered clutch ring behind the chuck, with a drill-bit symbol at the end of its range that locks the clutch.
Gear shifter: A slide on top of the housing that selects the low-speed, high-torque range or the high-speed, low-torque range.
Variable-speed trigger: Speed rises with trigger travel; the tool brakes when the trigger is released.
Forward/reverse button: Sets rotation direction and serves as the lock-off in its center position.
Pistol grip: The handle set below the motor with a trigger inside a guard, the arrangement claimed in the 1917 Black & Decker patent.
Battery pack: Removable and rechargeable; released with a button and charged in a separate charger.
Worklight: A small lamp under the torque collar that lights when the trigger is squeezed, on the model described in the DEWALT manual.

Variants

Adjustable-clutch drill/driver: The common form: a clutch collar and a keyless chuck, sold in compact 12 volt class and larger 18 to 20 volt class sizes.
Dual-range (two-speed) drill/driver: A gear shifter selects a low or a high range. The DEWALT manual lists different maximum bit capacities for the two ranges.
Early battery drills: Makita lists a 6500D battery-powered drill in 1969 and a 6010D rechargeable drill in 1978 in its corporate history; Black & Decker lists a nickel-cadmium cordless drill in 1961.
Corded electric drill: The older form that the cordless tool derives from, such as the 1925 British Wolf drill in the Science Museum Group collection (1/2-inch chuck, universal motor rated 100 watts at 500 rpm).

Specifications

Voltage · V: 10.8 (marketed as 12 V Max) in one manufacturer’s manualDrill/drivers are sold in several voltage classes; this value is from the DEWALT DCD700 manual and is one example, not a survey.
No-load speed · rpm: 0–400 low range; 0–1500 high range (same model)DEWALT DCD700 manual.
Maximum torque · N·m: 24 (same model)DEWALT DCD700 manual.
Chuck capacity · mm: 10 (same model)DEWALT DCD700 manual.
Maximum drilling capacity, wood and metal · mm: 20 wood, 10 metal (same model)DEWALT DCD700 manual.

Made to

IEC 62841-1
IEC 62841-2-1

Safety and care

Safety

The DEWALT manual warns that the drill may stall if overloaded and cause a sudden twist. It instructs the user to always expect the stall and to grip the drill firmly with both hands.
The manual instructs the user to anchor or clamp the workpiece firmly.
The manual instructs the user to remove the battery pack, or to place the forward/reverse button in the lock-off position, before changing accessories or making adjustments.
The manual warns against tightening a bit by gripping the front of the chuck and switching the tool on, and states that doing so can damage the chuck and cause injury.

Care

Store battery packs in a cool, dry place away from direct sunlight and excess heat or cold. For long storage the manufacturer recommends a charged pack kept out of the charger, and says packs should not be stored completely depleted (DEWALT manual).
Blow dust out of the housing vents with dry air when dirt collects, wearing eye protection and a dust mask. Clean non-metal parts with a cloth dampened with water and mild soap and never with solvents (DEWALT manual).
The DEWALT manual states that the tool needs no additional lubrication.

Tips

Read the collar number as a torque setting
The numbered collar is the clutch. A higher number allows more torque and a larger fastener, and the clutch slips when the setting is reached. The manual advises a few practice runs in scrap or an unseen area to find the right position.1
Set the collar to the drill symbol before boring
The drill-bit symbol locks the clutch. The manual says the symbol must align with the center line on top of the tool, because otherwise the clutch will slip while drilling.1
Use the low range for torque and the high range for speed
The gear shifter chooses low speed with high torque or high speed with low torque. The manual lists a larger maximum bit size in the low range (for example 1/4 inch in metal against 1/8 inch in the high range on its model) and says not to shift while the tool is running.1
Spend the variable-speed range at the start of a hole or screw
The manual recommends variable speed for starting holes or fasteners and says continuous use in the variable range may damage the switch. For variable-speed drills it says a center punch is not needed: start slowly and speed up once the bit is deep enough not to skip out.1
Ease off at the end of the hole
Reducing pressure and easing the bit through the last fraction of the hole minimizes stalling and breakout. For thin material the manual advises a wood back-up block to prevent damage to the material.1
Keep the motor running while withdrawing the bit
The manual says this helps prevent the bit from jamming in a drilled hole. If the drill stalls it says to release the trigger immediately and find the cause rather than clicking the trigger on and off.1
Seat the bit about three-quarters of an inch deep and tighten with both hands
The manual says to insert the accessory about 19 mm (3/4 inch) into the chuck, then turn the sleeve with one hand while holding the tool with the other for maximum tightness. The automatic spindle lock is what allows this.1

History

Earliest documented

1914 (patent application filed 4 December 1914; granted 6 November 1917)

Baltimore, Maryland, United States

Samuel Duncan Black and Alonzo Galloway Decker, assignors to the Black & Decker Manufacturing Company, describe a drill with a pistol-grip hand support and a trigger. The specification states that with practically all portable electric hand-supported drills before their invention the user had to release the grip of at least one hand to some extent to operate the switch, and that the new arrangement allows the switch to be operated with a finger in the manner of a pistol trigger. The patent refers to the drill itself as “of known construction,” so the electric hand drill predates the grip. The National Inventors Hall of Fame says virtually all of today’s electric drills descend from the original portable hand-held drill patented in 1917.1 2

The cordless drill-driver is the product of three separate changes to the electric drill, and the first of them is the grip. The 1914 Black & Decker application starts from a problem of control. The specification says that with practically all hand-supported electric drills then in use the operator had to relax the grip of at least one hand to reach the switch, and it proposes a pistol-grip support with a finger-operated trigger so that neither hand needs to be released. The same patent calls the drill itself a drill “of known construction,” which places the electric hand drill before 1914. The grip and trigger that nearly every drill still uses are the part of the form that this patent claims.

The second change removed the cord. Black & Decker says that in 1961 it introduced the first cordless electric drill, using nickel-cadmium cells, and it lists a Black & Decker built power head on the Apollo Lunar Surface Drill used on Apollo 15 in 1971. Makita’s accounts of its own battery tools differ in date and in what they call first: its global history lists a battery-powered drill in 1969 and a nickel-cadmium drill in 1978, while Makita U.S.A. calls its 1978 7.2 volt drill its first cordless power tool. These are company statements, and the question of which firm made the first cordless drill is set out under disputed.

The third change was the battery. The tools moved from nickel-cadmium to nickel-metal-hydride cells, which Makita dates to its 1997 show exhibit, and then to lithium-ion, which the Royal Swedish Academy of Sciences says entered the market in 1991. Makita lists its first lithium-ion tool in 2005. A current example of the result is the 12 volt class DEWALT model in the sources, whose manual gives a maximum torque of 24 newton meters and a weight of 0.91 kilograms without its battery pack.

The drill-driver name comes from the clutch and the gearing. A tool that only drilled would need a stiff drive, but a screw driven to its seat by a stiff drive strips or snaps. The numbered clutch collar described in the manufacturer’s manual slips at a set torque, and a two-range gearbox lets the same motor turn a large bit slowly with high torque or a small bit quickly. One tool therefore covers boring and driving. This is what the cordless drill-driver took over from the separate corded drill and the hand screwdriver, which the archive treats under their own entries.

Timeline

1914
Black and Decker file the application, Serial No. 875,489, for an electrically driven tool with a pistol-grip support and trigger-operated switch, on 4 December.1
1917
US Patent 1,245,860 is granted on 6 November. Black & Decker’s own milestones page lists 1917 as the year of its patented ½-inch portable electric drill with a pistol grip and trigger switch.1 2
1925
S. Wolf & Co. of London make a British Wolf electric motor drill with a 1/2-inch chuck and a 100-watt universal motor at 500 rpm, now in the Science Museum Group collection.1
1961
Black & Decker says it introduces the world’s first cordless electric drill, powered by nickel-cadmium cells.1
1969
Makita’s corporate history lists the 6500D battery-powered drill, which it calls its first rechargeable power tool, in April.1
1971
Black & Decker says an Apollo Lunar Surface Drill with a Black & Decker built power head removed core samples on NASA’s Apollo 15 mission, and that the drill later served on Apollo 16 and 17.1
1978
Makita introduces its 6010D rechargeable drill in December, listed as its first nickel-cadmium battery tool. Makita U.S.A. dates its first 7.2 volt cordless drill to 1978 after ten years of design and testing.1 2
1991
Lithium-ion batteries enter the market, according to the Royal Swedish Academy of Sciences.1
1997
Makita exhibits the 6213D rechargeable driver-drill at the Chicago Hardware Show, listed as its first nickel-metal-hydride battery tool.1
2005
Makita launches the TD130D in February, listed as its first lithium-ion battery tool; Makita U.S.A. says it created the 18 volt lithium-ion category in 2005.1 2

Where the sources disagree

Which company made the first cordless drill, and when?

1961: Black & Decker introduced the world’s first cordless electric drill, powered by nickel-cadmium cells.1
Black & Decker (company milestones page)
April 1969: the 6500D battery-powered drill was Makita’s first rechargeable power tool. December 1978: the 6010D was its first nickel-cadmium battery tool.1
Makita Corporation (global company history)
1978: Makita introduced its first 7.2 volt cordless drill after ten years of design and testing.1
Makita U.S.A. (company page)

When was the pistol-grip drill patent applied for?

Black & Decker’s milestones page lists 1917 and describes it as the year it filed a patent application.1
Black & Decker
The application was filed 4 December 1914 and the patent granted 6 November 1917.1
US Patent 1,245,860

Gaps in the record (7)

The Black & Decker 1961 cordless drill has not been matched to a patent or a dated catalog page, so the 1961 date rests on the company’s milestones page.
The NASA record of the Apollo Lunar Surface Drill has not been located and read.
The earliest electric hand drills before 1914, including the German firm Fein’s drill of the 1890s that secondary accounts mention, have not been sourced to a primary record.
Makita’s 1969 and 1978 models are known only from Makita’s own timelines.
No independent test of torque, run time or durability has been sourced, so buying is null.
IEC 62841-2-1 has not been read; the standard slugs are inferred.
The specs table rests on one manufacturer’s manual and is not a survey of the product class.