SCAFFOLD LOCKING MECHANISM WITH TENSION INDICATOR
A wheeled scaffold assembly includes a locking mechanism to immobilize a scaffold after the scaffold has been positioned to be used as a work platform. The scaffold assembly may include multiple locking mechanisms. Further, the locking mechanism may include an indication to provide visual confirmation that the locking mechanism is appropriately engaged.
This application claims the benefit, under 35 U.S.C. §119(e), of U.S. Provisional Patent Application Nos. 60/673,860 filed Apr. 22, 2005 and 60/720,315 filed Sep. 23, 2005, the disclosures of each of which are hereby expressly incorporated by reference herein.
FIELD OF THE DISCLOSUREThe present disclosure relates to a locking mechanism for wheeled scaffolding. More specifically, the disclosure relates to a locking mechanism which is engaged from the scaffold work platform to actuate a locking foot to engage the floor under the scaffolding to immobilize the scaffold.
BACKGROUNDScaffolding is known to be used as a support platform for workers performing work on elevated work surfaces such as high walls and ceilings. A scaffold structure may include casters to provide for mobility of the scaffold from one location to another location. This is especially useful in situations where workers move regularly in performing their work. For example, when plastering a ceiling, workers cover the area accessible from the scaffold. When it is necessary to move to a new location, the workers utilize the wheels of the scaffold to adjust the position of the scaffold while still occupying the support platform by pulling on the ceiling or wall to move the scaffold to a new location.
Occupational safety regulations have been implemented to address the use of wheeled scaffolds by requiring that the scaffold be locked in place at any time that work is being performed from the support platform. This requirement has driven the use of locking wheels on the scaffold so that when the scaffold has been moved to a new work location, the wheels can be locked to prevent unexpected movement of the scaffold while the work is being completed. The result of these regulations is that workers must now dismount the scaffold to unlock the wheels and reposition a scaffold in a new location. This, in turn, reduces the efficiency of the worker, due to the time required for the worker to dismount the scaffold, unlock the wheels, reposition the scaffold, and remount the scaffold to perform work in the new location.
SUMMARYThe present disclosure comprises one or more of the features recited in the appended claims and/or the following features which, alone or in any combination, may comprise patentable subject matter:
According to one aspect of the present disclosure, a scaffold comprises a frame, a platform supported by the frame, a plurality of wheels coupled to the frame, and a locking mechanism coupled to the frame. The locking mechanism may be moveable between a first position wherein the locking mechanism is configured to engage a floor supporting the scaffold and a second position wherein the locking mechanism is configured to be spaced-apart from the floor. The locking mechanism may spring-loaded.
The locking mechanism may further comprise an actuator moveable between a locked position and an unlocked position, a first plunger coupled to the locking handle, the first plunger including a guide portion engaging a second plunger, an extension spring engaging a portion of the first plunger and a portion of the second plunger, the extension spring urging the first plunger and second plunger apart, wherein the second plunger is configured to engage the floor in the locked position and be spaced-apart from the floor in the unlocked position.
In some embodiments, the first plunger may further comprise a first indicator and the second plunger may further comprise a second indicator, the spacing between the first indicator and second indicator indicative of the relative position of the first plunger to the second plunger. In some embodiments, the first indicator may be spaced-apart from the second indicator when the second plunger is in the unlocked position and the first indicator may be aligned with the second indicator when the second plunger is in the locked position. In some embodiments, the distance between the first plunger and second plunger when the locking mechanism is in the unlocked position may be adjustable.
According to another aspect of the present disclosure, a locking mechanism for a scaffold may comprise a mounting bracket configured to be mounted to a scaffold, a first plunger coupled to the mounting bracket, and a second plunger coupled to the first plunger. The first plunger may be moveable relative to the second plunger between an unlocked position wherein a first end of the second plunger is engaged with a second end of the first plunger and a locked position wherein the first end of the second plunger is spaced-apart from the second end of the first plunger. The locking mechanism may further comprise a bias member interposed between a portion of the first plunger and a portion of the second plunger to urge the first and second plungers apart. The floor-engaging member may be spaced-apart from the floor in the unlocked position and is engaged with the floor in the locked position.
In some embodiments, the locking mechanism may further comprise a bias member interposed between a portion of the first plunger and a portion of the second plunger to urge the first and second plungers apart. In some embodiments, the locking mechanism may further comprise an actuator coupled to the first plunger, the actuator configured to move the first plunger between the locked and unlocked positions. The actuator may comprise a toggle lock handle.
In some embodiments, the first plunger may further comprise a first indicator and the second plunger may comprise a second indicator and the spacing between the first indicator and second indicator indicative of the relative position of the first plunger to the second plunger. The first indicator may comprise a tube and the second indicator may comprise a line. In some embodiments, the first indicator may be spaced-apart from the second indicator when the second plunger is in the unlocked position and the first indicator may be aligned with the second indicator when the second plunger is in the locked position.
According to still another aspect of the disclosure, a locking mechanism for a scaffold may comprise a mounting bracket configured to be mounted to a scaffold, a first plunger coupled to the mounting bracket, a second plunger coupled to the first plunger and moveable relative to the plunger, a spring coupled to and positioned between a drive end of the first plunger and a first end of the second plunger. The locking mechanism may be moveable between an unlocked position where the first end of the second plunger is spaced-apart a first distance from the drive end of the first plunger and a locked position where the first end of the second plunger is spaced-apart a second distance less than the first distance from the drive end of the second plunger.
In some embodiments, the first plunger may further comprise a first indicator and the second plunger may further comprise a second indicator. The spacing between the first indicator and second indicator may be indicative of the relative position of the first plunger to the second plunger. In some embodiments, the first indicator may be spaced-apart from the second indicator when the second plunger is in the unlocked position and the first indicator may be aligned with the second indicator when the second plunger is in the locked position. The distance between the first plunger and second plunger when the locking mechanism is in the unlocked position may be adjustable.
According to still another aspect of the disclosure, a method of operating a locking mechanism coupled to a scaffold having a plurality of wheels and moveable relative to a floor supporting the scaffold includes adjusting the locking mechanism to align a first indicator on a first portion of the locking mechanism with a second indicator on a second portion of the locking mechanism when the locking mechanism is in a locked position, positioning the scaffold in a work position, and actuating the locking mechanism to urge a portion of the locking mechanism into engagement with a floor supporting the scaffold to prevent the scaffold from rolling with respect to the floor.
Additional features, which alone or in combination with any other feature(s), including those listed above and those listed in the claims, may comprise patentable subject matter and will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the invention as presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGSThe detailed description particularly refers to the accompanying figures in which:
A scaffold assembly 10, shown in
Henceforth, reference is made to only one locking mechanism; however, the structure of the other locking mechanisms 28 is the same. The locking mechanism 28 is actuable between an unlocked position (not shown) wherein a runner 52 of a floor-engaging portion 56 is spaced-apart from a floor 58 supporting the scaffold assembly 10 and a locked position (shown in
Locking mechanism 28 further comprises an bias member 46 (shown in
Referring now to
First plunger 40 includes a main portion 43 and a guide portion 44 which passes through the center of bias member 46 and is received in second plunger 48. Second plunger 48 includes an aperture 74 (shown in
Guide portion 44 includes a threaded portion 45 which is threaded into female threads (not shown) in a lower end 47 of main portion 43 of first plunger 40. Flange portion 42 also includes female threads (not shown) and is adjustable along the length of guide portion 44 to change the relative spacing between drive end 49 of flange portion 42 and first end 50 of second plunger 48. This facilitates adjustment of the operating length of locking mechanism 28 as well adjustment of the pre-load of spring 46 and thereby allow user to adjust locking mechanism 28 to develop sufficient force of engagement with floor 58 to immobilize scaffold assembly 10 from rolling relative to floor 58.
When locking mechanism 28 is actuated to engage floor 58, runner 52 engages floor 58 before actuator 38 reaches the second, locked position. During a portion of the actuation, first plunger 40 continues to actuate while runner 52 and second plunger 48 are engaged with the floor 58. Guide portion 44 extends into second plunger 48 and bias member 46 is compressed. When the locking mechanism 28 is disengaged from the floor 58, guide portion 44 engages second plunger 48 as shown in solid in
Referring now to
Referring again to
Second plunger 48 is retained by a guide tube 36 which is coupled to two guide supports 34 on the lower mounting bracket 32. Lower mounting bracket 32 also includes a frame engaging member 66 which is coupled to frame leg 18 by bolts 26 and nuts 27. Guide tube 36 has an inner diameter which is slightly larger than the outer diameter of second plunger 48 and is sized such that second plunger 48 moves within guide tube 36 freely. Lower mounting bracket 32 positions guide tube 36 in an orientation that is aligned with the aperture in the guide support 34 of the upper mounting bracket 30 so that the first plunger 40 and second plunger 48 are maintained in an orientation which is generally perpendicular to floor 58. In the illustrative embodiment, guide supports 34 are welded to frame engaging member 66. However, it is contemplated that guide support 34 may be coupled to frame engaging member 66 through any of a number of fastening methods including screws, bolted joints, adhesives, or hook and loop fastening systems. Guide tube 36 is coupled to guide supports 34 through welded joints.
In the illustrative embodiment of
In another embodiment of a locking mechanism 128, shown in
As shown in
Although certain illustrative embodiments have been described in detail above, variations and modifications exist within the scope and spirit of this disclosure as described and as defined in the following claims.
Claims
1. A locking mechanism for a scaffold comprising:
- a mounting bracket configured to be mounted to a scaffold,
- a first plunger coupled to the mounting bracket, and
- a second plunger coupled to the first plunger;
- wherein the first plunger is moveable relative to the second plunger between an unlocked position wherein a first end of the second plunger is engaged with a second end of the first plunger and a locked position wherein the first end of the second plunger is spaced-apart from the second end of the first plunger.
2. The locking mechanism of claim 1, wherein the locking mechanism further comprises a bias member interposed between a portion of the first plunger and a portion of the second plunger to urge the first and second plungers apart.
3. The locking mechanism of claim 1, further comprising a floor-engaging member configured to engage with a floor supporting the scaffold.
4. The locking mechanism of claim 3, wherein the floor-engaging member is spaced-apart from the floor in the unlocked position and is engaged with the floor in the locked position.
5. The locking mechanism of claim 1, further comprising an actuator coupled to the first plunger, the actuator configured to move the first plunger between the locked and unlocked positions.
6. The locking mechanism of claim 5, wherein the actuator comprises a toggle lock handle.
7. The locking mechanism of claim 1, wherein the first plunger further comprises a first indicator and the second plunger further comprises a second indicator, the spacing between the first indicator and second indicator indicative of the relative position of the first plunger to the second plunger.
8. The locking mechanism of claim 7, wherein the first indicator comprises a tube and the second indicator comprises a line.
9. The locking mechanism of claim 8, wherein the first indicator is spaced-apart from the second indicator when the second plunger is in the unlocked position and the first indicator is aligned with the second indicator when the second plunger is in the locked position.
10. A locking mechanism for a scaffold comprising:
- a mounting bracket configured to be mounted to a scaffold,
- a first plunger coupled to the mounting bracket,
- a second plunger coupled to the first plunger and moveable relative to the plunger,
- a spring coupled to and positioned between a drive end of the first plunger and a first end of the second plunger, and
- wherein the locking mechanism is moveable between an unlocked position where the first end of the second plunger is spaced-apart a first distance from the drive end of the first plunger and a locked position where the first end of the second plunger is spaced-apart a second distance less than the first distance from the drive end of the second plunger.
11. The locking mechanism of claim 10, wherein the first plunger further comprises a first indicator and the second plunger further comprises a second indicator, the spacing between the first indicator and second indicator indicative of the relative position of the first plunger to the second plunger.
12. The locking mechanism of claim 11, wherein the first indicator is spaced-apart from the second indicator when the second plunger is in the unlocked position and the first indicator is aligned with the second indicator when the second plunger is in the locked position.
13. The locking mechanism of claim 12, wherein the distance between the first plunger and second plunger when the locking mechanism is in the unlocked position is adjustable.
14. A scaffold comprising:
- a frame,
- a platform supported by the frame,
- a plurality of wheels coupled to the frame, and
- a locking mechanism coupled to the frame, the locking mechanism moveable between a first position wherein the locking mechanism is configured to engage with a floor supporting the scaffold and a second position wherein the locking mechanism is configured to be spaced-apart from the floor.
15. The scaffold of claim 14, wherein the locking mechanism is spring-loaded.
16. The scaffold of claim 14, wherein the locking mechanism further comprises an actuator moveable between a locked position and an unlocked position, a first plunger coupled to the locking handle, the first plunger including a guide portion engaging a second plunger, an extension spring engaging a portion of the first plunger and a portion of the second plunger, the extension spring urging the first plunger and second plunger apart, wherein the second plunger is configured to engage the floor in the locked position and be spaced-apart from the floor in the unlocked position.
17. The scaffold of claim 16, wherein the first plunger further comprises a first indicator and the second plunger further comprises a second indicator, the spacing between the first indicator and second indicator indicative of the relative position of the first plunger to the second plunger.
18. The scaffold of claim 17, wherein the first indicator is spaced-apart from the second indicator when the second plunger is in the unlocked position and the first indicator is aligned with the second indicator when the second plunger is in the locked position.
19. The scaffold of claim 18, wherein the distance between the first plunger and second plunger when the locking mechanism is in the unlocked position is adjustable.
20. A method of operating a locking mechanism coupled to a scaffold having a plurality of wheels and moveable relative to a floor supporting the scaffold, the method comprising the steps of:
- positioning the scaffold in a work position,
- adjusting the locking mechanism so that an first indicator on a first portion of the locking mechanism is aligned with an second indicator on a second portion of the locking mechanism when the locking mechanism is in a locked position, and
- actuating the locking mechanism such that the floor-engaging member engages the floor to immobilize the scaffold from rolling with respect to a floor supporting the scaffold.
Type: Application
Filed: Apr 20, 2006
Publication Date: Nov 2, 2006
Inventor: Eugene Perry (Mooresville, IN)
Application Number: 11/379,511
International Classification: E04G 3/28 (20060101); E04G 1/18 (20060101);