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EP-4273362-B1 - TELESCOPING LADDER

EP4273362B1EP 4273362 B1EP4273362 B1EP 4273362B1EP-4273362-B1

Inventors

  • KIEFFER, MITCHELL I.
  • Caldwell, Allen A.
  • Schlueter, Nathan L.

Dates

Publication Date
20260513
Application Date
20151202

Claims (12)

  1. A foldable ladder (10), comprising: a first ladder portion (14, 250); a second ladder portion (16, 254) hingedly attached to the first ladder portion (14, 250), each of the first and second ladder portions (14, 16) comprising: a first stile (214); a second stile (216), the first and second stiles (214, 216) each having a plurality of columns (22) disposed along an axis of the plurality of columns (22); and a plurality of rungs (24) extending between the first stile (214) and the second stile (216), each rung (24) connected to a column of the first stile (214) and a column of the second stile (216); a pair of hinge mechanisms hingedly connecting the first ladder portion (14, 250) to the second ladder portion (16, 254) about a hinge axis (50), each hinge mechanism adapted to lock the first and second ladder portions (14, 16) such that the first ladder portion (14, 250) and the second ladder portion (16, 254) form an angle therebetween, each hinge mechanism comprising: a first hinge member (52) operably connected to the first ladder portion (14, 250); a second hinge member (54) operably connected to the second ladder portion (16, 254), the first and second hinge members (52,54) rotatable with respect to each other about the hinge axis (50); a shifting mechanism (70), comprising: a shift pattern (72) defined by a plurality of slots (74, 76, 78) positioned peripherally on the first hinge member (52), each slot corresponding to an angular position of the first ladder portion (14, 250) with respect to the second ladder portion (16, 254), and adjacent slots are separated by a distance defined along a perimeter of the first hinge member (52); and a selector pin (84) adapted to be shifted in the shift pattern (72) and received by a slot to lock the second ladder portion (16, 254) at an angular position with respect to the first ladder portion (14, 250); a locking plate (100) in the second hinge member (54), the locking plate (100) comprising a plurality of recesses (112, 114, 116) such that a center of the locking plate (100) coincides with the hinge axis (50), each recess separated from another recess by an angle corresponding to the angle between the first and second ladder portions (14, 16); and a locking pin (120) connected to the selector pin (84), the locking pin (120) adapted to be received by a recess of the locking plate (100), the locking pin (120) configured move in a direction along an axis of the locking pin (120), wherein the locking pin (120) moves into a recess of the locking plate (100) when the selector pin (84) moves into a slot of the shift pattern (72); the locking pin (120) moves away from a recess of the locking plate (100) when the selector pin (84) moves away from a slot of the shift pattern (72); and the locking pin (120) and the selector pin (84) are coupled such that the central axis of the locking pin (120) is transversely located at an angle with respect to the axis of the selector pin (84).
  2. The foldable ladder (10) of claim 1, wherein the angle between the first and second ladder portions (14, 16) is between about 0 degrees and about 180 degrees.
  3. The foldable ladder (10) of claim 2, wherein the first and second ladder portions (14, 16) are lockable at angles of about 0 degrees, about 30 degrees and about 180 degrees.
  4. The foldable ladder (10) of claim 3, wherein the angle between a first recess (112) of the plurality of recesses (112, 114, 116) and a second recess (114) of the plurality of recesses (112, 114, 116) is about 30 degrees, and the angle between the first recess (112) and a third recess (116) of the plurality of recesses (112, 114, 116) is about 180 degrees.
  5. The foldable ladder (10) of claim 4, wherein the locking pin (120) is configured to be: fully received by a recess to lock the first ladder portion (14, 250) and the second ladder portion (16, 254) in an angular position; fully retracted from a recess to release the first and second ladder portions (14, 16) from an angular position; and abut against an edge of the second hinge member (54) when the first and second ladder portions (14, 16) are angled at any angle other than a plurality of predetermined angles.
  6. The foldable ladder (10) of any preceding claim, further comprising a selection collar (142) slidingly engaging with the first hinge member (52), the selection collar (142) engaging with the selector pin (84) and adapted to slide against the first hinge member (52) along a collar axis (144).
  7. The foldable ladder (10) of claim 6, wherein the selection collar (142) is adapted to rotate about the collar axis (144) to move the selector pin (84) along the groove defined on the first hinge member (52).
  8. The foldable ladder (10) of any preceding claim, further comprising one or more safety indicators, the safety indicators adapted to provide a first indication when the first and second ladder portions (14, 16) are locked at an angular position and a second indication when the first and second ladder portions (14, 16) are unlocked.
  9. The foldable ladder (10) of any preceding claim, wherein each rung (24) comprises a planar upper surface and a second surface opposite to the planar upper surface, wherein the first surface of the first and second ladder portions (14, 16) define a planar standing surface when the first and second ladder portions (14, 16) form an angle of about 180 degrees.
  10. The foldable ladder (10) of claim 9, wherein at least a portion of the first surface of the first and second ladder portions (14, 16) forms an angle with respect to a horizontal plane.
  11. The foldable ladder (10) of any preceding claim, wherein the plurality of columns (22) are disposed in a nested arrangement for relative axial movement in a telescopic fashion such that the ladder is extendable or collapsible along the axis of the plurality of columns (22).
  12. The foldable ladder (10) of claim 11, wherein each rung (24) is connected to a column of the plurality of columns (22) by a connector assembly (28), the connector assembly (28) having a latch assembly including a release button (246) slidable along a front surface of the rung (24) to unlock or selectively lock the relative axial movement between two adjacent columns (22) of the plurality of columns (22), the front surface of the rung (24) being generally perpendicular to a plane normal to the axis of the plurality of columns (22).

Description

BACKGROUND Ladders typically include rungs supported between stiles formed from a plurality of columns. In some cases, the ladder can be a telescoping ladder and can be expanded to separate the columns from one another for extension of the ladder, or collapsed together for retraction of the ladder. Such ladders often include mechanisms which can allow the ladder to be folded for storage and unfolded during use. US5954157A (D1) discloses a combination step and extension ladder manufactured of prestressed filament wound composite material such as fiberglass is disclosed. The inner and outer side rails are molded, filament wound composite material (fiberglass) wherein the fibers are continuous and angularly oriented with respect to the longitudinal axis of the respective side rails. Hinges are provided on each of the inner side rails of the ladder and hinge actuators are located in the front edges of the outer side rails so that the ladder may be folded, unfolded or locked in either a closed, step ladder or straight extension ladder configuration, by depressing the hinge actuators, irrespective of the longitudinal position of the inner rail sections with respect to the outer rail sections. The inner side rails are telescopically mounted within channeled portions of the outer rails and interfaced with an "interlocking tongue and groove joint" such that the inner side rails can be extended to increase the height of the ladder in either configuration without compromising the torsion characteristics of the outer rail under a weighted load. Both the inner and outer side rails have composite rungs, integrally molded into the sides to produce a homogeneous casting. Ladder accessories are provided that facilitate stability and convenient use during operation thereof. SUMMARY OF THE INVENTION Features of the invention are set out in claim 1. Preferred features of the invention are set out in the dependent claims. BRIEF DESCRIPTION OF DRAWINGS The following drawings are illustrative of particular embodiments of the present invention and therefore do not limit the scope of the invention. The drawings are not necessarily to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the invention will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements. Figure 1A is a perspective view of a foldable ladder locked at a first angular position according to an embodiment;Figure 1B is a perspective view of the foldable ladder of FIG. 1A locked at a second angular position;Figure 2A is a perspective view of the foldable ladder of FIG. 1A locked at a third angular position shown in a collapsed state;Figure 2B is a perspective view of the foldable ladder of Figure 2A shown in an extended state;Figure 2C is a close-up perspective view of portion "2C" of Figure 2B;Figure 2D is a left side view of the foldable ladder of portion "2D" of Figure 1A showing only the rungs of the first and second ladder portion;Figure 2E is a sectional plan view of a portion of the ladder showing details of a connector assembly according to an embodiment;Figure 3 is a perspective view of a hinge mechanism according to an embodiment;Figure 4A is a side view of the hinge mechanism of Figure 3 with the selection collar removed from view for showing certain details of the hinge mechanism;Figure 4B is a side perspective view of the hinge mechanism of Figure 3 shown in an unlocked state with the selection collar removed from view for showing certain details of the hinge mechanism;Figure 4C is a side view of the hinge mechanism shown in Figure 4B with the second hinge member and the selection collar removed from view for showing certain details of the hinge mechanism;Figure 5 is a cross-sectional view of the hinge mechanism taken along the line 5-5 shown in Figure 3;Figure 6 is a detailed view of the hinge mechanism of Figure 5 with certain components of the first hinge member removed from view to show certain details of the hinge mechanism;Figure 7 is a detailed perspective view of a locking pin, a locking plate, a selector pin and a biasing spring according to an embodiment;Figure 8A is a cross-sectional side view of the hinge mechanism of Figure 5 with certain features removed from view for showing certain details of the hinge mechanism;Figure 8B is a close-up view of portion 8B of Figure 8A;Figure 9A is a perspective view of a foldable ladder locked at a first angular position according to an embodiment;Figure 9B is a perspective view of the foldable ladder of FIG. 9A locked at a second angular position in a collapsed state;Figure 9C is a perspective view of the foldable ladder of Figure 9B shown in an extended state;Figure 9D is a perspective view of the foldable ladder of FIG. 9A locked at a third angular position;Figure 10A is a close-up perspective view of a portion 10A of the ladder shown in Figure 9A;Figure 10B is