| JP3236305 | Workbench and workbench |
| US6471000B2 | 2002-10-29 | |||
| US3885647A | 1975-05-27 | |||
| US4111280A | 1978-09-05 | |||
| US4643377A | 1987-02-17 | |||
| US4712754A | 1987-12-15 | |||
| US1151510A | 1915-08-24 | |||
| US4336706A | 1982-06-29 |
CLAIMS
1. A safety ladder that protects a climber from a fall, comprising: a) a supported ladder having a plurality of rungs; b) an elongated channel secured in a position next to the ladder, the channel having multiple flanges surrounding a passageway, a pair of the flanges defining there between a gap; c) a locking member that is configured to travel upwardly in the passageway, the locking member having a beam, a cam section at one end portion of the beam and a connector section positioned outside of the passageway; d) a cable connecting a climber to the connector section; and e) the cam section being configured to form an anchor with the channel in a locking position when a climber pulls down on the cable forcing the locking member to move downwardly.
2. The safety ladder of claim 1 wherein the cable connector section is an eyelet.
3. The safety ladder of claim 1 wherein the beam and cam section are a one piece structure.
4. The safety ladder of claim 1 wherein the cam section has a pair of opposed U-shaped surfaces. 5. The safety ladder of claim 1 wherein the cam bears against opposing surfaces of the channel.
6. The safety ladder of claim 1 wherein the channel includes a web, a pair of flanges connected to the web, and each of the flanges having a fold next to the gap.
7. The safety ladder of claim 1 wherein the locking member can be lifted relative to the channel by lifting on the cable.
8. The safety ladder of claim 1 wherein the cam section has a maximum length between the U-shaped surfaces that is greater than the maximum transverse thickness of the rail.
9. The safety ladder of claim 6 wherein the cam section engages the web and the flanges having the folds when in the locking position.
10. The safety ladder of claim 1 wherein the channel has an opening in one of the flanges that enables the locking member to be removed from or added to the channel via the opening.
11. The safety ladder of claim 1 further comprising stops mounted at intervals on the channel.
12. The safety ladder of claim 11 wherein each stop is wedge shaped. 13. The safety ladder of claim 11 wherein the stops are positioned about 1 to
2 feet (30 to 61 cm) apart.
14. The safety ladder of claim 11 wherein the locking member has a cam section with a tail that extends away from the cam section.
15. The safety ladder of claim 6 further comprising stops mounted at intervals on the channel, wherein each stop is wedge shaped.
16. The safety ladder of claim 15 wherein each stop is generally wedge shaped.
17. The safety ladder of claim 16 wherein each stop is connected to the web of the channel.
18. The safety ladder of claim 1 wherein one of the flanges has a locking member opening that enables the cam section of the locking member to be placed through the opening an into the gap.
19. The safety ladder of claim 18 wherein there are multiple spaced apart locking member openings.
20. The safety ladder of claim 19 wherein the locking member openings are spaced about 2-3 feet apart (61-91 cm).
21. The inventions substantially as shown and described herein. |
TITLE OF THE INVENTION LADDER SAFETY APPARATUS
INVENTOR:
ANDERSON, Patrick, K., a US citizen, of 18765 Perkins Road, Prairieville, LA 70769, US.
CROSS-REFERENCE TO RELATED APPLICATIONS Priority of my US Provisional Patent Application Serial No . 60/774,294, filed 16
February 2006, incorporated herein by reference, is hereby claimed. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable REFERENCE TO A "MICROFICHE APPENDIX"
Not applicable BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to safety devices for preventing inadvertent injury to a ladder climber by connecting the climber to the ladder with a harness arrangement that provides a locking member that slides in a vertically extended channel attached to the ladder during ascent and that forms an anchor in the event of a fall. More particularly, the present invention relates to an improved ladder safety apparatus that provides an elongated channel that extends upwardly along the ladder, the channel providing a passageway for holding a cam locking member, wherein the cam locking member can be pulled upwardly with little or no resistance but locks to provide an anchor when pulled downwardly such as when the climber falls.
2. General Background of the Invention
Workers are often required to climb to dangerous elevations such as when scaffolding is in use. It is known to bolt or otherwise rigidly attach an elongated vertically extended ladder to scaffolding so that workers can ascend dozens of feet (many meters) in the air in order to reach a selected level of a scaffolding. During this ascent, the climber
is subjected to potential injury or death if he or she loses a firm grip on the ladder.
Several patents have issued that relate generally to safety devices that help a climber when ascending a ladder.
The following US Patents are examples of such devices, each being incorporated herein by reference:
TABLE PATENT NO. TITLE ISSUE DATE
(MM-DD-YYYY)
BRIEF SUMMARY OF THE INVENTION
The present invention provides an improved ladder safety apparatus that features an elongated channel that is attached to and that extends along a ladder to be climbed. A cam locking member travels in the channel and can be pulled upwardly with little or no resistance as the climber ascends the ladder.
If the climber loses his or her grip on the ladder and falls, the cam locking member immediately grips the channel, preventing downward movement of the cam locking member. A lanyard, rope, or cable can be used to attach the user to the cam locking member by fastening to a belt, vest or harness worn by the user.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
Figure 1 is a fragmentary side view of the preferred embodiment of the apparatus of the present invention;
Figure 2 is a top view taken along lines 2-2 of figure 1;
Figure 3 is a partial perspective view of the preferred embodiment ofthe apparatus ofthe present invention;
Figure 4 is a partial perspective view of an alternative embodiment of the apparatus ofthe present invention;
Figure 5 is a partial perspective view ofthe preferred embodiment ofthe apparatus ofthe present invention; Figure 6 is a fragmentary side view ofthe preferred embodiment ofthe apparatus ofthe present invention;
Figure 7 is a fragmentary side view ofthe preferred embodiment ofthe apparatus ofthe present invention;
Figure 8 is a perspective view ofthe preferred embodiment ofthe apparatus ofthe present invention;
Figure 9 is another perspective view ofthe preferred embodiment ofthe apparatus ofthe present invention;
Figure 10 is a fragmentary side view of an alternate embodiment ofthe apparatus ofthe present invention; Figure 11 is a top view taken along lines 11-11 of figure 10;
Figure 12 is a partial perspective view of the alternate embodiment of the apparatus ofthe present invention;
Figure 13 is an elevation view ofthe preferred embodiment ofthe apparatus ofthe present invention showing connectable vertical channel sections; Figure 14 is a fragmentary view ofthe preferred embodiment ofthe apparatus of the present invention;
Figure 15 is a fragmentary view ofthe preferred embodiment ofthe apparatus of
the present invention;
Figure 16 is a partial sectional view of the preferred embodiment of the apparatus of the present invention;
Figure 17 is a side view of an alternate construction of the locking member; Figure 18 is a top view of the locking member of Figure 17;
Figure 19 is a perspective view of the locking member of Figure 17;
Figure 20 is side view of an alternate construction for the rail portion of the preferred embodiment of the apparatus of the present invention;
Figure 21 is a fragmentary side view of the embodiment of Figures 17 and 20 of the apparatus of the present invention;
Figure 22 is a similar view;
Figure 23 is a fragmentary side view of the embodiment of Figure 20 of the apparatus of the present invention. DETAILED DESCRIPTION OF THE INVENTION Ladder safety apparatus 10 is shown in figures 8 and 9 in use at a construction site having scaffolding 11 to which is attached an elongated vertically extended ladder 12. The ladder 12 attaches to the scaffolding 11 using a plurality of brackets 13 and a bolted connection 14, for example. Ladder 12 includes rails 15 and rungs 16.
In figures 4-9, an elongated vertical channel 17 is attached to ladder 12. The vertical channel 17 can include web 18 and flange 19, 20 sections. Each of the flanges 19, 20 has a folded portion for producing a narrowed gap 23. The flange 19 has folded portion 21. The flange 20 has folded portion 22 as shown in figure 5. The gap 23 is sized to be smaller than the width of the cam section 38 of locking member 35 measured between flat sides 39, 40 (see figure 2). In order to insert the locking member 35 into channel 17, an oval shaped opening 24 and slot 25 are provided as shown in figures 4-5.
Channel 17 is connected to ladder 12 using fittings 26. Each fitting 26 can include a u-shaped section 27 providing recess 28 and an ell shaped portion 29. The ell shaped portion 29 and u-shaped section 27 can be integrally joined, being formed from a single piece of metal, flat bar or the like. One or more of the fittings 26 can be provided with perforated plates 30, 31 that are receptive of a locking pin 32 as shown in figure 5. The locking pin 32 can be retained with a chain 33 and attachment 34 as shown.
The locking member 35 (figures 1-3) provides an elongated beam 36 having an
eyelet 37 at one end portion and cam section 39 at the other end portion. The cam section 38 has two u-shaped surfaces 41, 42 that are joined at reference line 43. A stop 44 on beam 36 prevents excess movement of the locking member 35 when a user pulls it upwardly such as when climbing the ladder 12 (see figure 6). In order to prevent injury to a user or climber 48 (see figures 4-9), a strap, rope, or cable 45 can be used with a hook 47 to form an attachment between locking member 35 and a climber 48. The climber 48 can be equipped with a harness 49, or vest or belt or other suitable device that attaches to cable 45 so that if a climber 48 falls, the locking action of the locking member 35 with the vertical channel 17 provides an anchor that will support the weight of the climber 48 as shown schematically in figure 9. In figure 7, locking member 35 rotates in the direction of arrow 46 should the climber 48 lose his or her grip on ladder 12. In such a case (see figure 7), u-shaped surface 42 engages web 18 of channel 17 while u-shaped surface 41 engages folded portions 21, 22.
Figures 10-12 show an alternate configuration for a locking member, designated by the numeral 55. Locking member 55 provides a beam 56 having an eyelet 57 at one end portion and a cam section 58 at its other end portion as shown. The cam section 58 has opposed flat sides 59, 60. The cam section 58 has opposed surfaces that can be curved at 61, 62. Stop 63 is welded to beam 56 using weld 64. Otherwise, the locking member 55 can be interchanged with the locking member 35 of figures 1-9. Figures 13-16 show an alternate configuration for vertical channel 17, mainly connectable sections 17A, 17B, 17C. The sections 17A, 17B, 17C can be provided in differing lengths as shown in figure 13, referencing the dimension lines A, B and C. Each of the sections 17A, 17B, 17C provides at its lower end portion a coupler 50. The coupler 50 can provide a web 51 and opposed flanges 52, 53 as shown in figures 13-15. The coupler 50 can be connected (for example, welded) to the lower end portion of any of the selected channels 17, 17A, 17B, 17C. A portion (for example, about one half) of the coupler 50 is welded to the selected channel 17, 17A, 17B, 17C leaving about one half extending below the selected channel, as shown in figure 15. In such a fashion, the upper end portion 54 of the selected channels 17, 17A-17C can be fitted to the area under any one of the selected channels 17A, 17B, 17C of figure 13 to complete a splice. Thus, the upper end portion 54 of a channel section 17A- 17C is fitted into the bottom of the coupler 50 that is attached to the lower end portion of a selected channel section 17A, 17B, 17C.
Figures 17-23 show an alternate construction for the rail 65 and locking member 71. The channel 65 has web 66 and flanges 67, 68 that provide an overall generally c- shaped transverse cross section. As with the channel 17 of figures 4-9, folded portions 84, 85 can be provided on flanges 66, 67. A locking member opening 69 in channel 65 is an oblong opening 69 that enables locking member 71 (figure 19) to be added to the space or gap 70 that is in between the flanges 67, 68. The oblong opening 69 is sized and shaped to receive the cam section 74 of locking member 71 including its tail or locking tab 79. The tail or locking tab 79 is not found on the locking member 35 of the preferred embodiments of figures 1-16. Locking member 71 provides a beam 72 and eyelet 73. The eyelet 73 is (as with the preferred embodiment) a location for the attachment of a safety cable 45 and hook 47 thereto.
The improvements to the channel 65 and locking member 71 shown in figures 17-
23 work in the same manner as was shown and described with respect to figures 1-16. The improvement of figures 17-23 provide locking tail or locking tab 79 and its engagement with the wedge 80 that is attached (for example, welded at opening 81) to web 66 of rail 65.
As with the preferred embodiment of figures 1-16, the locking member 71 provides a cam section 74 having sides 75, 76 and u-shaped surface 77. Locking surface 78 provides a tail or locking tab 79 as shown in figures 17-19. This tail or locking tab 79 engages wedge 80 as shown in figure 22 should a climber 48 inadvertently fall.
The wedge 80 has inclined surface 82 and transverse surface 83. If the climber 48 falls, as in figures 5-9 and related text herein, the cable 45 attached to eyelet 73 will pull down on the eyelet 73, creating a moment in beam 72 so that it rotates (see arrow 46, figure 7) locking tab or tail 79 engages web 66 at surface 83. As the climber 48 falls downwardly, the locking member 71 will travel a short distance until locking tail or locking tab 79 stops upon wedge 80 transverse surface 83. The wedges 80 can be spaced apart for example, between about 12 and 24 inches (30 and 61 cm), and preferably about 18" (46 cm) apart. The locking member openings 69 can be spaced between about 24 and 36 inches (61 and 91 cm) apart, and preferably about 32" (81 cm) apart. The wedges 80 can, for example, be about 1/8"- 1 inch (0.32 - 2.5 cm) wide, l/8"-2" (0.32 - 5.1 cm) high and 1/16" - 1/8" (0.16 - 0.32 cm) thick at their upper edges. The width of space 70 can
be around 1" (2.5 cm) for example.
The following is a list of parts and materials suitable for use in the present invention.
PARTS LIST
Part Number Description
10 ladder safety apparatus
11 scaffolding
12 ladder
13 bracket
14 bolted connection
15 rail
16 rung
17 vertical channel
17A vertical channel section
17B vertical channel section
17C vertical channel section
18 web
19 flange
20 flange
21 folded portion
22 folded portion
23 gap
24 oval shaped opening
25 slot
26 fitting
27 u-shaped section
28 recess
29 ell shaped section
30 perforated plate
31 perforated plate
32 pin
33 chain
34 attachment
35 locking member
36 beam
37 eyelet 38 cam section
39 flat side
40 flat side
41 u-shaped surface
42 u-shaped surface 43 reference line
44 stop
45 cable
46 arrow
47 hook 48 climber
49 vest
50 coupler
51 web
52 flange 53 flange
54 upper end portion
55 locking member
56 beam
57 eyelet 58 cam section
59 flat side
60 flat side
61 u-shaped surface
62 u-shaped surface 63 stop
64 weld
65 channel
66 web
67 flange
68 flange
69 oblong opening 70 slot/gap
71 locking member
72 beam
73 eyelet
74 cam section 75 flat side
76 flat side
77 u-shaped surface
78 locking surface
79 tail/locking tab 80 wedge
81 opening
82 inclined surface
83 transverse surface
84 folded portion 85 folded portion
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.