COMBINATION BEAM SUPPORT AND LATCH MEANS FOR WALK-THROUGH PLATFORM
United States Patent 3565212
A platform, for scaffold use, having fixed and hinged flooring members mounted on a pair of beam supports, and in which the hinged flooring member carries a rigid latch member that wedges the beam supports apart as the hinged flooring member is closed and then allows the beam supports to spring back into gripped engagement with the latch member.
Application Number:
04/876633
Publication Date:
02/23/1971
Filing Date:
11/14/1969
View Patent Images:
Export Citation:
Assignee:
Up-right (Inc., Berkely)
Primary Class:
Other Classes:
182/180.100, 182/178.100, 182/186.800, 182/119
International Classes:
E04G1/15; E04G1/00; E04G5/08
Field of Search:
182/222,115,152,178,179
Primary Examiner:
Reinaldo, Machado P.
Attorney, Agent or Firm:
Mellin, Moore & Weissenberger
Claims:
1. A platform comprising: a. first and second elongated beam support members; b. a first flooring member supported by said beam support members and extending from adjacent ends thereof towards the other ends thereof; c. means for securing said adjacent ends of said beam support members to a structural member; d. means restraining said beam support members from relative movement in the vicinity of said first flooring member; e. a second flooring member supported on said beam support members and extending from the other ends thereof to said first flooring member; f. means mounting said second flooring member on said first beam support member for swinging movement of said flooring member into and out of engagement with said second beam support member; g. means for securing said other ends of said beam support members to a structural member so as to allow said other ends to move towards and away from each other; and h. latch means on said second flooring member movable into engagement with said second beam support member to wedge said first and second beam support members apart as said second flooring member is moved into engagement with said second beam support member.
2. A platform as set forth in claim 1, wherein said latch means also allows said first and second beam support members to move together from the wedged-apart position thereof when said second flooring member engages said second beam support member.
3. A platform as set forth in claim 1, wherein said means mounting said second flooring member on said first beam support member comprises a rigid brace secured to said second flooring member, which brace is pivotally mounted at one end thereof on said first beam support member and extends towards said second beam support member, and wherein said latch means is formed by the other end of said brace.
4. A platform as set forth in claim 3, wherein said second beam support member is circular in outer cross section and wherein said other end of said brace has an inclined face at an acute angle to said second flooring member and terminating at a distance normal to said flooring member which is greater than the radius of said second beam support member.
2. A platform as set forth in claim 1, wherein said latch means also allows said first and second beam support members to move together from the wedged-apart position thereof when said second flooring member engages said second beam support member.
3. A platform as set forth in claim 1, wherein said means mounting said second flooring member on said first beam support member comprises a rigid brace secured to said second flooring member, which brace is pivotally mounted at one end thereof on said first beam support member and extends towards said second beam support member, and wherein said latch means is formed by the other end of said brace.
4. A platform as set forth in claim 3, wherein said second beam support member is circular in outer cross section and wherein said other end of said brace has an inclined face at an acute angle to said second flooring member and terminating at a distance normal to said flooring member which is greater than the radius of said second beam support member.
Description:
This invention relates to scaffolds of the type shown in FIGS. 4--8 of U.S. Pat. No. 3,454,131, wherein a horizontal walk-through platform is provided which has a hinged flooring member that may be pivoted out of the way to allow a workman to climb through the opening provided thereby and which may then be closed to provide a complete floor on the platform.
In the aforesaid patent, the hinged flooring member is not provided with any sort of a latch to hold the flooring member in place when it is closed. As a consequence, the flooring member is free to swing open, making it awkward to handle the platform in erecting or dismantling the scaffold or in the storage thereof.
It is the principal object of this invention to provide a novel latch means for the hinged flooring member which will require a minimum of additional parts, which will utilize the beam supports of the platform as the movable parts of the latch, and which will be equally effective when the platform is incorporated into a scaffold or when detached therefrom.
Broadly speaking, the present walk-through platform is comprised of a pair of tubular beam support members covered by a fixed flooring member at one end and a hinged flooring member at the other. The beam support members are rigidly connected to each other in the vicinity of the fixed flooring member, but the ends of the beams are capable of resilient deformation away from each other in the vicinity of the hinged flooring member. The hinged flooring member is mounted on one of the beams and carries a latch device that will wedge between and spread the ends of the beams apart. The stiffness of the beams will then exert a force on the latch device to hold it closed. In addition, the latch device has an overcenter movement which allows the beams to spring back towards each other from their furthest wedged-apart position so that the hinged flooring member is held closed and cannot be reopened without the application of force sufficient to move the beams away from each other.
Other objects and advantages will become apparent in the course of the following detailed description.
In the drawings, forming a part of this application, and in which like parts are designated by like reference numerals throughout the same,
FIG. 1 is a perspective view of a scaffold using a platform member constructed in accordance with the present invention;
FIG. 2 is a plan view of the platform of Fig. 1;
FIG. 3 is a side elevational view of the platform of Fig. 2;
FIG. 4 is a view of the platform of FIG. 2, as seen from the underneath thereof;
FIG. 5 is a sectional view, taken on line 5-5 of FIG. 2;
FIG. 6 is a detailed view of a locking hook utilized at the ends of the platform;
FIG. 7 is a detail perspective view of the stop means of the hinged flooring member;
FIGS. 8--10 are views illustrating the movement of the platform beam supports as the hinged flooring member swings into place.
FIG. 1 illustrates the use of a walk-through platform 10 in a scaffold 11. The scaffold 11 comprises opposed end frames 12 and 13, each formed by vertical 14 and horizontal 15 structural members, such as aluminum or steel tubing. A stairway ladder 16 extends from lower platform 17 up to the walk-through platform 10, the ladder 16 being detachably connected to the same horizontal structural member 15 of end frame 13 as is platform 10. The opposite end of platform 10 is detachably secured to a horizontal structural member 15 of end frame 12 at the same height.
The scaffold can be built up to the desired height by attaching further end frames, stairway ladders and walk-through platform as indicated by the dot-and-dash lines in FIG. 1.
Platform 10 comprises a pair of tubular beam support members 21 and 22, each having a detachable hook 23 at each end thereof. As best seen in FIG. 6, these hooks have a throat 24 to receive one of the structural members 15 of the end frames therein. A spring-pressed pin 25 normally engages the bottom of the structural member 15 to prevent disengagement of the hook unless the pin is pushed, against the spring bias, into the hook. Fuller details of the locking hook 23 may be found in U.S. Pat. No. 2,665,950. Even though hooks 25, when secured to a structural member 15, will not allow the member 15 to move out of the throat, the hook may move axially along the member 15.
Cross braces 26 and 27 extend between and are welded to beams 21 and 22. A first flooring member 28 is supported by the aforesaid members, and secured thereto by bolts or rivets 29. The cross braces and first flooring member rigidify the beams 21 and 22 in the vicinity of this flooring member so that the beams are restrained from relative movement.
Rigid tubular cross braces 30 and 31 extend radially from beam 21 and are connected thereto by connectors 32 and 33 mounted in the ends of braces 30 and 31 and which encircle beam 21 and allow the braces to swing freely in planes normal to the beam. The cross braces 30 and 31 are secured together by tubular brace 34 extending therebetween and welded thereto.
A second flooring member 35 is mounted on braces 30, 31 and 34 and secured thereto by bolts or rivets 36.
As will be noted from FIG. 4, the end 37 of cross brace 31 terminates short of beam 22 when the flooring member 35 is closed. Brace member 30, however, is provided with an end cap 38 inserted into and welded into the end thereof. As best seen in FIGS. 8--10, end cap 38 has an inclined face 39 at an acute angle to the flooring member 35 which terminates at 40 and is then reversely curved to form a cam surface 41. The point 40 is spaced below flooring member 35 at a distance normal to the flooring member which is greater than the radius of beam 22.
As described above, the beams 21 and 22 of platform 10 are mounted by hooks 23 on opposed structural members 15 of the scaffold. The beams 21 and 22 are connected together rigidly in the vicinity of the flooring member 28 so that they cannot move together or apart. However, there is no such corresponding permanent bracing at the other ends of the beams and they may move towards and apart from each other.
FIG. 8 illustrates the relative position of the platform parts as the hinged platform 35 is moved to a closed position. The centerline 43 of support member 22 represents the normal position of beam 22 when no horizontal force is applied thereto. The end cap 38 of brace 30 is formed so that the greatest length of brace 30, i.e., at point 40, is greater than the normal distance between beams 21 and 22, when no horizontal force is applied therebetween. Thus, when the hinged platform 35 is closed, the cam surface 41 on end cap 38 will engage the beam 22 above the center thereof.
Continued closing movement will wedge the brace 30 between the beams 21 and 22 and will cause beam 22 to move sideways to a position indicated by the centerline 44, resulting in an amount of movement indicated by the arrows a in FIG. 9. This amount of movement a-a is the total amount of relative movement between the support members 21 and 22, and either one or both of these members will move on the structural member 15 to allow such movement.
Closing is completed when the flooring member 35 engages the top of beam 22. In this position, the point 40 on end cap 38 will have passed below the center of beam 22 so that the latter may move back, under its natural resilience, to the position indicated by centerline 45 and through the distance indicated by the arrows b--b in FIG. 10, and the beam will engage the inclined face 39 of the end cap.
The platform may be opened by applying a sufficient upward force to the edge of the flooring member 35 adjacent beam 22 to force the beams apart, i.e., through the distance b--b, so that the platform may then be swung freely open.
Opening movement of the hinged flooring member 35 is limited to slightly beyond 90° by means of pins 46 which are secured to connector 33 and move therewith into engagement with the radially extending pins 47 secured to beam 21.
If desired, brace 31 could be used as the latching member, instead of brace 30 as specifically illustrated herein. Brace 31 would provide a stiffer latch since it would engage the beams 22 and 23 at points thereon which are closer to the rigid cross brace 27 than where the beams are engaged by brace 30.
The above-described structure provides a simple but effective positive latch with a minimum amount of parts, due to the dual use of the beams 21 and 22, which act as the beam supports for the platform and which provide the resilient force to hold the hinged flooring in latched position.
In the aforesaid patent, the hinged flooring member is not provided with any sort of a latch to hold the flooring member in place when it is closed. As a consequence, the flooring member is free to swing open, making it awkward to handle the platform in erecting or dismantling the scaffold or in the storage thereof.
It is the principal object of this invention to provide a novel latch means for the hinged flooring member which will require a minimum of additional parts, which will utilize the beam supports of the platform as the movable parts of the latch, and which will be equally effective when the platform is incorporated into a scaffold or when detached therefrom.
Broadly speaking, the present walk-through platform is comprised of a pair of tubular beam support members covered by a fixed flooring member at one end and a hinged flooring member at the other. The beam support members are rigidly connected to each other in the vicinity of the fixed flooring member, but the ends of the beams are capable of resilient deformation away from each other in the vicinity of the hinged flooring member. The hinged flooring member is mounted on one of the beams and carries a latch device that will wedge between and spread the ends of the beams apart. The stiffness of the beams will then exert a force on the latch device to hold it closed. In addition, the latch device has an overcenter movement which allows the beams to spring back towards each other from their furthest wedged-apart position so that the hinged flooring member is held closed and cannot be reopened without the application of force sufficient to move the beams away from each other.
Other objects and advantages will become apparent in the course of the following detailed description.
In the drawings, forming a part of this application, and in which like parts are designated by like reference numerals throughout the same,
FIG. 1 is a perspective view of a scaffold using a platform member constructed in accordance with the present invention;
FIG. 2 is a plan view of the platform of Fig. 1;
FIG. 3 is a side elevational view of the platform of Fig. 2;
FIG. 4 is a view of the platform of FIG. 2, as seen from the underneath thereof;
FIG. 5 is a sectional view, taken on line 5-5 of FIG. 2;
FIG. 6 is a detailed view of a locking hook utilized at the ends of the platform;
FIG. 7 is a detail perspective view of the stop means of the hinged flooring member;
FIGS. 8--10 are views illustrating the movement of the platform beam supports as the hinged flooring member swings into place.
FIG. 1 illustrates the use of a walk-through platform 10 in a scaffold 11. The scaffold 11 comprises opposed end frames 12 and 13, each formed by vertical 14 and horizontal 15 structural members, such as aluminum or steel tubing. A stairway ladder 16 extends from lower platform 17 up to the walk-through platform 10, the ladder 16 being detachably connected to the same horizontal structural member 15 of end frame 13 as is platform 10. The opposite end of platform 10 is detachably secured to a horizontal structural member 15 of end frame 12 at the same height.
The scaffold can be built up to the desired height by attaching further end frames, stairway ladders and walk-through platform as indicated by the dot-and-dash lines in FIG. 1.
Platform 10 comprises a pair of tubular beam support members 21 and 22, each having a detachable hook 23 at each end thereof. As best seen in FIG. 6, these hooks have a throat 24 to receive one of the structural members 15 of the end frames therein. A spring-pressed pin 25 normally engages the bottom of the structural member 15 to prevent disengagement of the hook unless the pin is pushed, against the spring bias, into the hook. Fuller details of the locking hook 23 may be found in U.S. Pat. No. 2,665,950. Even though hooks 25, when secured to a structural member 15, will not allow the member 15 to move out of the throat, the hook may move axially along the member 15.
Cross braces 26 and 27 extend between and are welded to beams 21 and 22. A first flooring member 28 is supported by the aforesaid members, and secured thereto by bolts or rivets 29. The cross braces and first flooring member rigidify the beams 21 and 22 in the vicinity of this flooring member so that the beams are restrained from relative movement.
Rigid tubular cross braces 30 and 31 extend radially from beam 21 and are connected thereto by connectors 32 and 33 mounted in the ends of braces 30 and 31 and which encircle beam 21 and allow the braces to swing freely in planes normal to the beam. The cross braces 30 and 31 are secured together by tubular brace 34 extending therebetween and welded thereto.
A second flooring member 35 is mounted on braces 30, 31 and 34 and secured thereto by bolts or rivets 36.
As will be noted from FIG. 4, the end 37 of cross brace 31 terminates short of beam 22 when the flooring member 35 is closed. Brace member 30, however, is provided with an end cap 38 inserted into and welded into the end thereof. As best seen in FIGS. 8--10, end cap 38 has an inclined face 39 at an acute angle to the flooring member 35 which terminates at 40 and is then reversely curved to form a cam surface 41. The point 40 is spaced below flooring member 35 at a distance normal to the flooring member which is greater than the radius of beam 22.
As described above, the beams 21 and 22 of platform 10 are mounted by hooks 23 on opposed structural members 15 of the scaffold. The beams 21 and 22 are connected together rigidly in the vicinity of the flooring member 28 so that they cannot move together or apart. However, there is no such corresponding permanent bracing at the other ends of the beams and they may move towards and apart from each other.
FIG. 8 illustrates the relative position of the platform parts as the hinged platform 35 is moved to a closed position. The centerline 43 of support member 22 represents the normal position of beam 22 when no horizontal force is applied thereto. The end cap 38 of brace 30 is formed so that the greatest length of brace 30, i.e., at point 40, is greater than the normal distance between beams 21 and 22, when no horizontal force is applied therebetween. Thus, when the hinged platform 35 is closed, the cam surface 41 on end cap 38 will engage the beam 22 above the center thereof.
Continued closing movement will wedge the brace 30 between the beams 21 and 22 and will cause beam 22 to move sideways to a position indicated by the centerline 44, resulting in an amount of movement indicated by the arrows a in FIG. 9. This amount of movement a-a is the total amount of relative movement between the support members 21 and 22, and either one or both of these members will move on the structural member 15 to allow such movement.
Closing is completed when the flooring member 35 engages the top of beam 22. In this position, the point 40 on end cap 38 will have passed below the center of beam 22 so that the latter may move back, under its natural resilience, to the position indicated by centerline 45 and through the distance indicated by the arrows b--b in FIG. 10, and the beam will engage the inclined face 39 of the end cap.
The platform may be opened by applying a sufficient upward force to the edge of the flooring member 35 adjacent beam 22 to force the beams apart, i.e., through the distance b--b, so that the platform may then be swung freely open.
Opening movement of the hinged flooring member 35 is limited to slightly beyond 90° by means of pins 46 which are secured to connector 33 and move therewith into engagement with the radially extending pins 47 secured to beam 21.
If desired, brace 31 could be used as the latching member, instead of brace 30 as specifically illustrated herein. Brace 31 would provide a stiffer latch since it would engage the beams 22 and 23 at points thereon which are closer to the rigid cross brace 27 than where the beams are engaged by brace 30.
The above-described structure provides a simple but effective positive latch with a minimum amount of parts, due to the dual use of the beams 21 and 22, which act as the beam supports for the platform and which provide the resilient force to hold the hinged flooring in latched position.