Door handle is an ambiguous term and includes door latches, bars, and door knobs. Depending on the geographic location and their place in time, they vary in design, shape, and materials. The only constant is its function: an accessory used to open or close a door.
Functions of knobs and handles
The first existing gates are approximately 5000 years old. Door handles, as devices for manipulating an entrance door, became a necessity soon after the invention of the rotary mechanism. To most, pivots are simply known as hinges; however, there are almost as many hinge designs and configurations as there are handles.
The simplest handle is a push or pull projection on the opposite side of the hinge. Shaft placement is generally where it will provide optimal mechanical advantage; most doors function as second-class levers. Doors with handles or rings in the center, or a pivot point at a location other than a door edge, use first or third class lever principles.
Depictions of door handles in paintings dating to the 1st century CE are centrally placed hinged rings. The modern knocker is a holdover from this primitive door handle style. The doors were usually secured with bars and brackets to prevent them from being opened by intention or accident.
Knobs with latches and bars
Over time, the large cross bars used to secure a door were replaced by sliding bars, operated by a handle secured to the bar and protruding through a slot in the door, or as a pivot bar, often called latch, which could be fitted into a matching slots in the door leg. In colonial America, the operating mechanism for a small pivot bar was a latch chain that passed through a hole in the door near the handle. There are accounts and references, probably apocryphal, that this mechanism was a solution to heavy taxes and a crown edict ordering colonists to use only bolts or door locks imported from England.
Around the mid-18th century, handles and locks were integrated into a single unit, the earliest known examples being levers that operated the latch and served as a pull to open the door.
knobs and handles
The handle, as it exists today, is a relatively new invention dating to the mid-19th century, with the first US patent dated to the 1850s. Handles and knobs underwent a massive period of growth and development throughout the Victorian era (1830-1900). Thousands of variations on the door handle theme, in combination with modern production methods, made door handles accessible to virtually everyone. Deadbolts have waned in popularity and use, relegated to service in barns and similar outbuildings where their simplicity and design function trump outward appearance.
Manage value-added features
These handles today fulfill multiple functions. These functions may include lock and key mechanisms, electronic locks, push button access that is mechanical or electronic, high security features, and many other applications beyond a simple push and pull device to open or close a door.
For most Americans, the terms handle and knob are synonymous. In Europe, however, door levers make up the vast majority of door handles. Due to their utility and accessibility, door levers are gaining popularity in the United States. They are much easier to operate for a person with physical problems from arthritis, illness, or injury than round doorknobs. While large, exterior door handles will eventually be supplanted by self-opening mechanisms, door handles will continue to be required for smaller doors on interior doors, cabinets, and other furniture for centuries to come.