Look a little closer
See the mechanism
A straight movement spreads a radial frame
Read the diagram
Ribs pivot from the fixed top joint. Stretchers connect them to the runner, so raising that shared sleeve moves the ribs outward. A separate holding feature retains the open runner.
Simplified long-shaft frame, one radial section. Folding-rib joints, an automatic spring mechanism and detailed catch hardware are omitted.
Diagram basis: Umbrella runner disclosure; Rib and stretcher joints.
Sources: United States patent specification, hosted by Google Patents · United States patent specification, hosted by Google Patents · United States patent specification, hosted by Google Patents · Fulton Umbrellas
The runner is the part that gathers the movement
A conventional long-shaft umbrella has a fixed joint near the top and a runner that slides along the shaft below it. The ribs hinge at the upper joint. Shorter members called stretchers connect the runner to points along those ribs. Patents describing umbrella frames distinguish the fixed upper attachment from the sliding lower one.
That arrangement puts many links under one control. You do not open each rib individually; you move a shared attachment. Each stretcher receives movement from the same runner and acts on its own rib. The canopy is carried by the frame rather than being inflated from inside. Begin by locating those structural members, because fabric can hide the much smaller linkage doing the work beneath it.
Sources: United States patent specification, hosted by Google Patents · United States patent specification, hosted by Google Patents
The distance between two joints sets the rib angle
Follow one rib and its stretcher. Their ends turn at joints while the runner moves along the shaft. Moving the runner toward the fixed top joint changes the distance between two corners of the linkage. The connected bars must change their angles, moving the rib outward.
That linkage repeats around the shaft. Each stretcher shares the same runner, so moving one sleeve changes the angles throughout the frame. A straight movement along the shaft becomes spreading movement in several radial directions, opening a structure much wider than the sliding part that controls it.
Sources: United States patent specification, hosted by Google Patents · United States patent specification, hosted by Google Patents
The fabric needs the frame's support
The canopy attaches to the frame and spreads as the ribs move apart. In the large-umbrella disclosure cited here, the covering is secured centrally at the top and around its perimeter to the ribs. The relevant point is the relationship: the frame establishes the supporting layout, and the fabric occupies the spaces between supports.
Opening spreads the cloth around a central shaft rather than pulling it tight along one line. Look upward beneath an open umbrella and you can see the repeated supports, joints and stretchers. The canopy lies over that frame, covering the mechanism that establishes its shape.
Sources: United States patent specification, hosted by Google Patents · United States patent specification, hosted by Google Patents
Opening the frame and holding it open are different tasks
If the runner could freely slide down again, the frame could collapse toward its closed state. A holding mechanism keeps it at the needed position. Conventional spring catches are described in the background of US2937653A, whose own invention provides another latch arrangement for large umbrellas. The existence of different catches is a reason not to prescribe one universal release action.
The stretchers convert runner movement into rib movement; the catch prevents the runner from sliding back once the umbrella is open. Releasing the catch allows the runner to move again. The linked ribs then follow that movement toward the closed state.
Sources: United States patent specification, hosted by Google Patents · United States patent specification, hosted by Google Patents
Automatic opening changes the source of the movement
The frame principle and the way a user supplies energy are separate questions. A manual umbrella uses the user's movement of the runner. Automatic models add a mechanism that initiates opening when released. Fulton's range includes automatic and manual umbrellas, while the basic rib-and-runner layout remains a useful starting point for understanding the canopy.
Compact folding umbrellas add joints in the ribs and telescoping shaft sections so the closed frame fits into a shorter package. Those extra movements are distinct from spreading the canopy. A button, spring system and folding links can change how the frame is operated and stored without eliminating the runner's coordinating role.
Sources: Fulton Umbrellas · United States patent specification, hosted by Google Patents
A frame can need controlled flexibility
Fulton describes additional frame flexibility as a way to reduce stress on ribs and notes that some of its umbrellas are designed to recover from inversion. That is a separate question from how the runner opens the frame. An umbrella can have a perfectly legible linkage and still behave differently when wind loads the canopy from underneath.
The design is therefore more than a set of rigid bars. Joints coordinate motion, supports spread the cloth, a holding feature retains the open state, and material behavior affects how the structure responds to load. Wind resistance is not an unlimited weather guarantee. The maker's care and operating advice applies to the actual umbrella; forcing an unfamiliar inverted or damaged frame is not a demonstration of the linkage.
Sources: Fulton Umbrellas
Questions you might still have
What is an umbrella runner?
The ring or sleeve that slides along the shaft and carries the inner ends of the stretchers, coordinating the frame's opening and closing.
Sources: United States patent specification, hosted by Google Patents
What is the difference between ribs and stretchers?
Ribs support the canopy from the upper joint. Stretchers connect the sliding runner to those ribs and transmit movement to them.
Sources: United States patent specification, hosted by Google Patents
Does the opening mechanism also keep it open?
Linkage and retention are distinct jobs. A catch or other holding feature retains the runner after the frame has spread.
Sources: United States patent specification, hosted by Google Patents
The thing to remember
The runner changes one shared distance along the shaft, and hinged stretchers convert that change into coordinated movement of many ribs.
What this example leaves out
A simplified conventional long-shaft frame in radial section. Folding ribs, automatic spring sequences, catch details and wind performance vary. The figure is not a repair guide, exact cutaway or rated-load test.
Sources & further reading
Source access dates are listed below. Manufacturer descriptions and patents support the specific constructions described, not every product.
- US1240645A — Umbrella-runner ↗
United States patent specification, hosted by Google Patents · Retrieved 2026-10-14 · Runner slides on shaft, carries articulated stretcher ends, with top notch carrying ribs.
Historical joint construction; simplified long-shaft frame only, not an exact contemporary product. - US720537A — Umbrella rib and stretcher-joint ↗
United States patent specification, hosted by Google Patents · Retrieved 2026-10-14 · Ribs attach at stationary upper ferrule and braces at sliding lower runner; canopy attachment is separate.
Joint-layout disclosure, not a universal frame repair guide. - US2937653A — Supporting and release catch for umbrella runners ↗
United States patent specification, hosted by Google Patents · Retrieved 2026-10-14 · Conventional spring catches support a raised runner; disclosed large-umbrella alternative uses a different latch.
Background supports separate holding function. The original schematic omits detailed catches and does not prescribe release action. - FAQs — Care and wind-resistant frames ↗
Fulton Umbrellas · Retrieved 2026-10-14 · Flexible frames reduce rib stress, some models recover from inversion, and wet umbrellas should dry open; the page lists manual and automatic model families.
Manufacturer's own designs; no universal wind speed, weather guarantee or forced-reset advice.
