The disclosure relates to ladders. More particularly, the disclosure relates to ladders used on steep-pitched roofs. Additionally, the disclosure relates to horizontally and vertically traversing steep-pitched roofs. Additionally still, the disclosure relates to equipment for anchoring persons while on a steep-pitched roof.
Roofs can be constructed with surfaces thereof having a steep pitch, and various roof workers must traverse the steep-pitched roofs. Roof workers include but are not limited to: satellite-dish installers, home-owners, chimney workers, telecommunications personnel, and electricians.
By way of example, to install a satellite dish, a roof worker typically climbs a traditional ladder in order to access the roof. The roof worker then traverses vertically on the roof to determine a height for the dish, traverses horizontally on the roof to determine a lateral position for the satellite dish, and places the satellite dish at the determined height and lateral position on the roof. The height and lateral position of the satellite dish are determined as the optimal place on the roof for the satellite dish to receive satellite signals. Thus, roof workers traverse both horizontally and vertically on steep-pitched roofs in order to install satellite equipment.
When a roof worker horizontally and vertically traverses a steep-pitched roof, a variety of problems can arise. First, footing is unstable. Continuing with the example above, unstable footing leads to less efficient satellite-dish installations because roof workers dedicate time and energy to maintaining a firm footing in addition to installing equipment. The loss of time and energy is not recoverable and is a built-in cost of doing business for companies that install satellite dishes. Second, persons and companies must carry insurance in the event someone has trouble balancing both his/her own weight and/or the weight of any equipment, resulting in a fall and/or injury of the roof worker, the equipment, and/or other people. Insurance adds to the cost of owning a steep-pitched roof or doing business on steep-pitched roofs for persons and companies.
In order to vertically traverse a steep-pitched roof after accessing the steep pitch with a traditional ladder, a roof worker can use what is known in the prior art as a “chicken ladder.”
A ladder is used on a steep-pitched roof, and an embodiment of the ladder comprises a first section having a plurality of rungs, a second section connected to the first section, a third section connected to the second section, and a paw pivotally connected to the third section. The third section has a length less than or equal to a length of the second section, and the third section also has a length less than a distance between a first rung of the plurality of rungs and an end of the first section.
The first section has an inner surface, the second section has an inner surface, and the third section has an inner surface. Each of the first section and the second section and the third section comprises a first rail and a second rail extending parallel to the first rail. Each of the plurality of rungs has ends attached to an outer surface of the first section.
A castor can be positioned on the first section, and the distance between the first rung of the plurality of rungs and the end of the first section is less than or equal to a distance between the castor and the end of the first section. An anchor member can be positioned on the first section. A pad extends along the inner surface of the first, second, and third sections. A bumper can be attached to an outer surface of the first section and to an outer surface of the second section. The bumper can be attached to the end of the first section and to an end of the second section.
The paw of the ladder comprises an ankle member pivotally attached to the third section, a foot member attached to the ankle member, and a sole member attached to an underside of the foot member. The sole member has a width greater than a width of the foot member.
The ladder can be used in a system with a roof anchor apparatus on a steep-pitched roof, where the steep-pitched roof has a ridge and a first surface extending from the ridge and a second surface extending from the ridge and where an embodiment of the roof anchor apparatus is used over the ridge of the steep-pitched roof and has a first portion angularly connected to a second portion, a first shoe interconnected to the first portion of the roof anchor apparatus and positioned on the first surface of the steep-pitched roof, and a second shoe interconnected to the second portion of the roof anchor apparatus and positioned on the second surface of the steep-pitched roof. The first portion of the roof anchor apparatus is positioned at an angle relative to the second portion of the roof anchor apparatus, and the first shoe and the second shoe are at least partially formed of a rubber material.
A method uses the ladder and the roof anchor apparatus to traverse a steep-pitched roof, and an embodiment of the method comprises rolling the castor on the outer surface of the first section of the ladder up the first surface of the steep-pitched roof so that the outer surface of the ladder faces the first surface of the steep-pitched roof during the step of rolling, positioning the castor of the ladder adjacent the ridge and on the first surface so that a plane of the paw of the ladder clears the ridge and so that the paw of the ladder is positioned above the first surface of the roof during the steps of rolling and positioning, flipping the ladder so that the paw of the ladder is positioned above the second surface of the roof and so that the inner surface of the first section of the ladder faces the first surface of the roof after the step of flipping, and sliding the ladder downwardly along the first surface of the roof until the paw of the ladder engages the second surface of the roof. The pad of the ladder is positioned between the first surface of the roof and the inner surface of the ladder. The sole member of the paw contacts the second surface of the roof. A person using the ladder and roof-anchor apparatus can tie-off to an anchor member connected to the first section of the ladder. A person using the ladder and roof anchor apparatus can then tie-off to an anchor member connected to the first portion or second portion of the roof anchor apparatus. In the method, the first shoe of the roof anchor apparatus is placed on the first surface of the roof, and the second shoe of the roof-anchor apparatus is placed on the second surface of the roof.
The description that follows includes exemplary apparatus, system, and methods that embody the inventive subject matter. While the apparatus, system, and methods are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. All embodiments are preferred.
It should be appreciated that the disclosed apparatus, system, and methods can be utilized by any person on a steep-pitched roof. Persons that can utilize the disclosed apparatus and method can include, but are not limited to, satellite-dish installers, home-owners, roofers, chimney workers, telecommunications personnel, and electricians.
Referring to
The first section 101 has an inner surface 104, the second section 120 has an inner surface 123, and the third section 130 has an inner surface 133. The first section 101 has a first rail 109 and a second rail 110 extending parallel to the first rail 109, the second section 120 has a first rail 125 and a second rail 126 extending parallel to the first rail 125, and the third section 130 has a first rail 134 and a second rail 135 extending parallel to the first rail 134.
A castor 140 can be positioned on the first section 101, and the distance between the first rung 107 of the rungs 106 and the end 102 of the first section 101 is less than or equal to a distance between the castor 140 and the end 102 of the first section 101. In
A pad 153 extends along the inner surfaces 102, 123, 133 of the first, second, and third sections 101, 120, 130, respectively. A pair of bumpers 150 can be attached to the outer surface 105 of the first section 101 and to an outer surface 124 of the second section 120. The bumpers 150 can be attached to the end 102 of the first section 101 and to an end 121 of the second section 120.
The paw 160 of the ladder 100 has an ankle member 161 pivotally attached to the third section 130, a foot member 162 attached to the ankle member 161, and a sole member 163 attached to an underside 164 of the foot member 162. The sole member 163 has a width greater than a width of the foot member 162. The ankle member 161 is pivotally attached to the end 131 of the third section 130. In
A first pair of support members 170 extends between the first section 101 and the second section 120. One of the first pair of support members 170 extends between the first rail 109 of the first section 101 and the first rail 125 of second section 120. Another of the first pair of support members 170 extends between the second rail 110 of the first section 101 and the second rail 126 of the second section 120. A second pair of support members 171 extends between the third section 130 and the second section 120. One of the second pair of support members 171 extends between the first rail 134 of the third section 130 and the first rail 125 of second section 120. Another of the second pair of support members 171 extends between the second rail 135 of the third section 130 and the second rail 126 of the second section 120.
The first section 101, second section 120, third section 130, and rungs 106 can be made of one-inch outer-diameter tubular aluminum. The first section 101 can have a length of approximately 6′6″. The second section 120 can have length of approximately 18″. The third section 130 should have a length less than or equal to approximately 18″ because the ladder 100 can sit too high over a ridge of a roof when the third section 130 is greater than 18″. The second section 120 should extend perpendicular to the first section 101, and the end 102 of the first section 101 should connect to the end 121 of the second section 120. The third section 130 should extend perpendicular to the second section 120, and the opposite end 122 of the second section 120 should connect to the opposite end 132 of the third section 130. The third section 130 thus should be parallel to the first section 101. The distance between rails 109 and 110, 125 and 126, 134 and 135 should be less than the width of a traditional ladder, and said distance can be approximately 12″ so that the ladder 100 can easily be carried up a traditional ladder to the steep-pitched roof.
The first, second, and third sections 101, 120, and 130 of the ladder 100 can be integrally formed for easy transport and use. Thus, no time is wasted adapting the ladder 100 for use with another ladder, assembling the ladder 100, or disassembling the ladder 100.
Referring to
The sole member 263 and pads 253 and 286 can be formed of a compressible and form-fitting polymer with a high wear-resistance, such as a rubber. The material of the sole member 263 and pads 253 and 286 can have a melting point higher than the hottest temperatures a roof can reach when exposed to the sun. For example, some roofs are known to reach 130.degrees. F in the sun; thus, the material of the sole member 263 and pads 253 and 286 should have a melting point higher than 130.degrees. F. Also, material of the sole member 263 and pads 253 and 286 can have a low stiffness at low temperatures when roof shingles can be brittle. The stiffness at low temperatures should be less than a stiffness of metal at low temperatures.
In
The castor 240 is positioned on the first rung 207. In use of the ladder 200, the castor 240 is used to roll the ladder 200 up the first surface 292 of the roof 290 before flipping and placing the ladder 200 over the ridge 296 of the roof 290 (this method is described in more detail hereinbelow). Placing the castor 240 on one of the rungs 206 creates a need for only one castor 240 because castor 240 can evenly balance ladder 200 when placed in the center of one of the rungs 206. The castor 240 should be an inline castor with no swivel. Placing the castor 240 on rung 207 is significant. First, the castor 240 creates a height F above the first surface 292 of the roof 290 when the ladder 200 is rolled up surface 292 for placement of the ladder 200 over ridge 296. The larger the height F, the more clearance the end 202 of first section 201 has when rolling the ladder 200 up the surface 292 of the steep-pitched roof 290. Second, the castor 240 gives the roof worker a visual indication if the paw 260 has cleared the ridge 296 of the roof 290 so that paw 260 does not damage or compromise the integrity of the roof 290 when the ladder 290 is flipped in order to position the ladder 200 over the ridge 296.
Bumper 250 is placed on the ladder 200 to protect the ends 202 and 221 of the first and second section 201 and 220, respectively, when using the castor 240 to roll the ladder 200 up the surface 292.
The angle Θ between the first and second surfaces 292 and 294 is an acute angle. At angle Θ, the pad 253 on the first section 201 of the ladder 200 rests on the first surface 292 of the roof 290, and the ridge 296 of the roof 290 is placed where the first section 201 and the first pair of support members 270 meet. For angles smaller than Θ, the ridge 296 of the roof 290 is placed along the first pair of support members 270 closer to the second section 220 and the paw 260 pivots upwardly more toward the second section 220 and the third section 230 of the ladder 200 so that the sole member 263 of the paw 260 remains in full contact with the second surface 294 of the roof 290. For angles larger than Θ, the ridge 296 of the roof 290 is placed along the first section 201 at increasing distances away from the first pair of support members 270 as Θ increases and the paw 260 pivots downwardly away from the second section 220 and the third section 230, and then with further increasing angles Θ, outwardly away from the first section 201 and upwardly toward the third section 230.
The distance between the end 202 of the first section 201 of ladder 200 and the first rung 207 of rungs 206 is shown by distance D in
As can be seen in
In
Referring to
The castor 340 can be seen as in the center of rung 307. The anchor member 341 can be seen attached to the center of the rung 307 below the castor 340. Distance E is the distance between the end 302 of the first section 301 and end of the paw 360 and is also the combined length of the third section (not shown) and the paw 360. Distance D is the distance between the end 302 of the first section 301 and the first rung 307. Distance D is also the distance between the end 302 of the first section 301 and the castor 340. Distance D is also the distance between the end 302 of the first section 301 and the anchor member 341. It should be appreciated the anchor member 241 can be positioned elsewhere on the first section 301. Distance E can be less than or equal to distance D. The width H of the ladder 300 and extension 380 can be approximately 12″. In use, at least a portion of the sole member 363 of the paw 360 faces the first section 301 of the ladder 300.
Referring to
The roof anchor apparatus 403 is positioned over the ridge 496 of the steep-pitched roof 490 and has a first portion 411 angularly connected to a second portion 417, a first shoe 432 interconnected to the first portion 411 and positioned on the first surface 492 of the steep-pitched roof 490, and a second shoe 433 interconnected to the second portion 417 and positioned on the second surface 496 of the steep-pitched roof 490. The first portion 411 of the roof anchor apparatus 403 is positioned at an angle relative to the second portion 417 of the roof anchor apparatus 403, and the first shoe 432 and the second shoe 433 are at least partially formed of a rubber material. The angle between the first and second portions 411 and 417 of the roof anchor apparatus 403 is approximately equal to the angle Θ between the first surface 492 and the second surface 494 of the steep-pitched roof 490.
The ladder 400 is also positioned over the ridge 496 of the steep-pitched roof 490. The paw 460 of the ladder 400 contacts the second surface 494 of the roof 490, and the inner surface (not visible) of the first section 401 contacts the first surface 492 of the roof 490. The ladder 400 is positioned next to the roof anchor apparatus 403, and the paw 460 of the ladder contacts the same roof surface 494 as the second shoe 433 of the apparatus 403 while the first portion 401 of the ladder 400 contacts the same roof surface 492 as the first shoe 432 of the apparatus 403. A roof worker can tie-off initially to the anchor member 441 of the ladder 400 in order to position the apparatus 403 over the ridge 496 of the roof 490. The roof worker can then tie-off to the anchor member 404 of the apparatus if the worker is working on the first surface 492 of the roof 490, or the roof worker can then tie-off to the anchor member 423 of the apparatus 403 if the worker is working on the second surface 494 of the roof 490.
The bumpers 450 can be seen on the end 402 of the outer surface 405 of the first section 401 and on the end 421 of the outer surface 424 of the second section 420. The castor 440 is positioned in the center of the first rung 407 of the rungs 406. The sole member 463 of paw 460 is wider than the foot member 462 of the paw 460. Bumpers 450 can be seen on both the first and second rails 409 and 410 of the first section 401 and the first and second rails 425 and 426 of the second section 420. The rungs 406 are attached to the outer surface 405 of the first section 401.
Now discussing the roof anchor apparatus 403 in more detail, the first portion 411 of the roof anchor apparatus 403 has an end 412 and an opposite end 413. The first shoe 432 is interconnected to the end 412 of the first portion 411. The second portion 417 of the roof anchor apparatus 403 has an end 418 and an opposite end 419. The second shoe 433 is interconnected to the end 418 of the second portion 417. The opposite end 419 of the second portion 417 is positioned adjacent the opposite end 413 of the first portion 411. The roof anchor apparatus 403 also has a first leg support 430 connected to the end 412 of the first portion 411 and to the first shoe 432, and a second leg support 431 connected to the end 418 of the second portion 417 and to the second shoe 433. In
In
An anchor member 404 can be connected to the first portion 411, and an anchor member 423 is connected to the second portion 417. The anchor members 404 and 423 allow a roof worker of satellite dishes to “tie-off” to the roof anchor apparatus 403. Placing anchor member 404 on the first portion 411 and anchor member 423 on the second portion 417 allow a roof worker to tie-off to the roof anchor apparatus 403 on either of the two surfaces extending from the ridge of a roof without changing the position of the roof anchor apparatus 403. In
A locking member 451 locks the first portion 411 at the angle relative to the second portion 417. The locking member 451 has a first side plate 453, a second side plate 454, and a cross bar 452. The cross bar 452 is connected to the first side plate 453 and to the second side plate 454. The first side plate 453 and the second side plate 454 are connected to the opposite end 413 of the first portion 411. The first side plate 453 and the second side plate 454 are also connected to the opposite end 419 of the second portion 417. Pins 455 connect the first plate 453 and the second plate 454 to the opposite end 419 of the second portion 417 of the roof anchor apparatus 403. The first plate 453 and the second plate 454 of the locking member 451 each have holes 456 formed therein, and the pins 455 are inserted into the appropriate holes 456 so that the first portion 411 of the roof anchor apparatus 403 extends at an angle relative to the second portion 417. The first and second side plates 453 and 454 can be connected to the first portion 411 with a permanent pivoting connection, a releasably attached pivoting connection, a releasably attached connection, and the like. In
The first shoe 432 has an upper pad layer 435, a foot 434 positioned under the upper pad layer 435, and a lower pad layer 436 positioned under the foot 434. The upper pad layer 435 and the lower pad layer 436 can be integrally wrapped around the foot 434. The second shoe 433 can be similar to the first shoe 432. The second shoe 433 has an upper pad layer 438, a foot 437 positioned under the upper pad layer 438, and a lower pad layer 439 positioned under the foot 437. The foot 434 of the first shoe 432 is connected to the first leg support 430 so that the first leg support 430 is positioned between the first shoe 432 and the first portion 411. Likewise, the foot 437 of the second shoe 433 is connected to the second leg support 431 so that the second leg support 431 is positioned between the second shoe 433 and the second portion 417. The first leg support 430 can extend perpendicular to the first portion 411, and the second leg support 431 can extend perpendicular to the second portion 417. The upper pad layer 438 and the lower pad layer 439 can be integrally wrapped around the foot 437.
The upper pad layers 435 and 438 and lower pad layers 436 and 439 can be formed of a compressible and form-fitting polymer with a high wear-resistance, such as a rubber. The material of the lower pad layers 436 and 439 can have a melting point higher than the hottest temperatures a roof can reach when exposed to the sun. For example, some roofs are known to reach 130.degrees. F in the sun; thus, the material of the lower pad layers 436 and 439 should have a melting point higher than 130.degrees. F. Also, material of the lower pad layers 436 and 439 can have a low stiffness at low temperatures when roof shingles can be brittle. The stiffness at low temperatures should be less than a stiffness of metal at low temperatures.
The first portion 411 has a first member 414 and a second member 415 extending in spaced parallel relationship with the first member 414. A third member 416 extends between the first member 414 and the second member 415 at end 412 of the first portion 411, and the third member 416 is connected to the first member 414 and to the second member 415. The third member 416 of the first portion 411 interconnects or connects to the first shoe 432. The configuration of the first member 414, second member 415, and third member 416 forms a rectangular shape, and it should be appreciated the members 414, 415, and 416 of the first portion 411 can also form other shapes such as a triangle or trapezoid. In
The second portion 417 has a first member 427 and a second member 428 extending in spaced parallel relationship with the first member 427. A third member 429 extends between the first member 427 and the second member 428 at end 418 of the second portion 417, and the third member 429 is connected to the first member 427 and to the second member 428. The third member 429 of the second portion 417 interconnects or connects to the second shoe 433. The configuration of the first member 427, second member 428, and third member 429 form a rectangular shape, and it should be appreciated the members 427, 428, and 429 of the second portion 417 can also form other shapes such as a triangle or trapezoid. In
In
It should be appreciated that the first and second members 414 and 415 of the first portion 411 can alternatively be interconnected or connected to the first shoe 432 instead of the third member 416. Likewise, it should be appreciated that the first and second members 427 and 428 of the second portion 417 be interconnected or connected to the second shoe 433 instead of the third member 429. Shoes 432 and 433 can interconnect or connect to the ends 412 and 418 of the portions 411 and 417, respectively, because experiments have shown the first shoe 432 and second shoe 433 have a more even and uniform contact with surfaces 492 and 494 of the steep-pitched roof 490. A more even and uniform contact with roof surfaces 492 and 494 is desirable because a larger surface area of contact is made between the shoes 432, 433 and the roof 490. A larger surface area of contact provides more frictional contact, which provides more stability and less movement of the roof anchor apparatus 403. Thus, the roof anchor apparatus 403 sits firmly over the ridge 496 of the roof 490.
It should be appreciated the first and second members 414, 415 can be connected with the third member 416 where the first and second members 414, 415 extend for the entire length of the first portion 411 and where the third member 416 extends between the first and second members 414, 415. Alternatively, the third member 416 can extend for the entire width of the first portion 411 where the first and second members 414, 415 do not extend past the ends of the third member 416. Likewise, it should be appreciated the first and second members 427, 428 can be connected with the third member 429 where the first and second members 427, 428 extend for the entire length of the second portion 417 and where the third member 429 extends between the first and second members 427, 428. Alternatively, the third member 429 can extend for the entire width of the first portion 417 where the first and second members 427, 428 do not extend past the third member 429.
The upper pad layers 435 and 438 and lower pad layers 436 and 439 can be formed of a compressible and form-fitting polymer with a high wear-resistance, such as a rubber. The material of the lower pad layers 436 and 439 can have a melting point higher than the hottest temperatures a roof can reach when exposed to the sun. For example, some roofs are known to reach 130.degrees. F in the sun; thus, the material of the lower pad layers 436 and 439 should have a melting point higher than 130.degrees. F. Also, material of the lower pad layers 436 and 439 can have a low stiffness at low temperatures when roof shingles can be brittle. The stiffness at low temperatures should be less than a stiffness of metal at low temperatures.
The roof anchor apparatus 403 is extremely stable while using only a few efficient points of contact (shoes 432 and 433) with the surfaces 492 and 494 extending from the ridge 496 of the roof 490. The shoes 432 and 433 frictionally contact roof surfaces 492 and 494, and the material of the shoes 432 and 433 holds against the roof surfaces 492 and 494 even at low and high temperatures without damaging or compromising the integrity of the roof surfaces 492 and 494. Thus, the roof-anchor apparatus 403 simultaneously provides a stable anchor for roof workers of satellite dishes and other roof workers while contacting the roof 490 with shoes 432 and 433 configured to hold against roof surfaces 492 and 494 without damaging or compromising the integrity of the roof surfaces 492 and 494.
The roof anchor apparatus 403 can have a telescoping mechanism 442 positioned on the first portion 411 and the second portion 417. The telescoping mechanism 442 of the first portion 411 telescopes a first side 443 of the first portion 411 relative to a second side 444 of the first portion 411. The first side 443 is inserted within the second side 444 in order to telescope the first portion 411. Pins 448 are inserted through holes in the first and second sides 443 and 444 to hold the first portion 411 at a desired length. The telescoping mechanism 442 of the second portion 417 telescopes a first side 445 of the second portion 417 relative to a second side 446 of the second portion 417. The first side 445 is inserted within the second side 446 in order to telescope the second portion 417. Pins 448 are inserted through holes in the first and second sides 445 and 446 to hold the second portion 417 at a desired length. The telescoping mechanism 442 should hold the first portion 411 and the second portion 417 at the same lengths to ensure the downward pressures exerted by the roof anchor apparatus 403 on the first and second shoes 432 and 433 maintain uniformity and consistency of contact with the first and second surfaces 492 and 494 of the steep-pitched roof 490.
Reference numerals from
The castor 440 of the ladder 400 is then positioned adjacent the ridge 496 and on the first surface 494 so that a plane of the paw 460 of the ladder 400 clears the ridge 496 and so that the paw 460 of the ladder 400 is positioned above the first surface 494 of the roof 490 while the ladder 400 is rolled and positioned, i.e. during the steps of rolling and positioning.
The ladder 400 is then flipped so that the paw 460 of the ladder 400 is positioned above the second surface 494 of the roof 490 and so that the inner surface (104 in
The ladder 400 then slides downwardly along the first surface 492 of the roof 490 until the paw 460 of the ladder 400 engages the second surface 494 of the roof 490. When the ladder 400 is in position over the ridge 496 of the roof 490, the pad of the ladder 400 is positioned between the first surface 492 of the roof 490 and the inner surface of the ladder 400. The sole member 463 of the paw 460 contacts the second surface 494 of the roof 490.
If the roof 490 is longer than the ladder 400, extensions (380 in
The first portion 411 of the roof anchor apparatus 403 can be set at an angle relative to the second portion 417 of the roof anchor apparatus. The angle between the first and second portions 411 and 417 of the roof anchor apparatus is approximately Θ, the angle between first surface 492 and second surface 494 of the roof 490 in
A roof worker using the ladder 400 and roof anchor apparatus 403 can tie-off to an anchor member 441 connected to the first section 401 of the ladder 400. A person using the ladder 400 and roof anchor apparatus 403 can then tie-off to an anchor member 404 connected to the first portion 411 or second portion 417 of the roof anchor apparatus 403. In some embodiments of the method, a roof worker can tie-off to the anchor member 441 before positioning the roof anchor apparatus 403 over the ridge 496 of the roof 490, and then the roof worker can tie-off to one of the anchor members 404 and 423 after the roof anchor apparatus 403 is positioned over the ridge 496.
Thus, after placing the ladder 400 and roof anchor apparatus 403 on roof 490, the second surface 494 of roof 490 has only two points of contact by the system 498: the paw 460 of the ladder 200, and the second shoe 433 of the roof anchor apparatus 403. After placing the ladder 400 and roof anchor apparatus 403 on roof 490, the first surface 492 of roof 490 has one point of contact: the first shoe 432 of the roof anchor apparatus 403. After placing the ladder 400 and roof anchor apparatus 403 on roof 490, the first surface 492 of roof 490 has a line of contact: the first section 401 of the ladder 400. The line of contact and points of contact provide superior stability and support for roof workers using the ladder 400, system 498, and methods.
It should be understood that the drawings and specification are not intended to limit the embodiments to the particular form(s) disclosed. It is intended that the disclosure shall cover all modifications, equivalents and alternatives falling within the spirit and scope of the following claims.
This application claims the benefit of, and incorporates by reference, U.S. Provisional Application No. 61/398,464, filed on Jun. 25, 2010. This application is a continuation-in-part of, and incorporates by reference, U.S. patent application Ser. No. 12/911,730, filed on Oct. 26, 2010.
Number | Date | Country | |
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61398464 | Jun 2010 | US |
Number | Date | Country | |
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Parent | 12911730 | Oct 2010 | US |
Child | 12954615 | US |