Method and apparatus for retrofitting existing escalator systems
A method and apparatus for retrofitting existing escalator systems in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.
1. Field of the Invention
The present invention relates generally to escalators that are disposed between spaced-apart floors of a building. More particularly, the invention concerns novel method and apparatus for retrofitting existing escalator systems in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.
2. Discussion of the Prior Art
Prior art moving stairways or escalators typically include a support truss and a plurality of interconnected steps that travel in a loop within the truss to provide a continuous movement along a specified path. When the escalator assembly is appropriately mounted between the floors of a building, the ends of the truss rest on concrete or steel supports provided at each floor. Typically, the ends of the truss are not rigidly connected to the supports, but rather provision is made for some relative movement between the escalator assembly and the building structure to prevent catastrophic failures during an earthquake.
California Elevator Code adopted in October, 1998 includes seismic requirements for escalators that require that escalators be connected to their structural supports in such a way as to be capable of resisting specified code seismic forces and, at the time, be sufficiently free to move so that they will not be damaged by the relative movement, called “story drift”, of the building structure at the upper and lower landings of the building that are spanned by the escalator assembly.
Certain presently existing escalator assembly designs of which applicant is aware accommodate story drift by providing special connection mechanisms at each of the building landings that permit some limited movement between the escalator assembly and affixed-to building construction. One form of such prior art connection mechanism includes a first specially designed structural steel member that is interconnected with the escalator structure and a second specially designed, cooperating structural steel member that is interconnected with a fixed structural component of the building structure. More particularly, one of the first and second structural steel members is provided with a rib portion and the other is provided with a slot that receives the rib portion. With this construction the rib portion is free to move within the slot thereby permitting some limited motion between the escalator assembly and fixed structural components of the building structure.
One of the most effective systems for accommodating story drift is described in U.S. Pat. No. 6,637,580 issued to the present inventor. This patent describes an escalator or moving stairway that is constructed to accommodate oscillation and lateral displacement of a first story relative to a second story of a building between which the escalator or moving stairway extends such as that which may occur during an earthquake. The escalator includes novel telescoping connector mechanisms that are connected at one end to a structural support of the building and are connected at the other end to supporting trusses of the escalator in a manner to permit relative movement between the supporting trusses and the floors of the first and second stories of the building.
Another prior art escalator assembly design that has been proposed to accommodate story drift requirements caused by earthquakes is disclosed in U.S. Pat. No. 6,129,198 issued to Nusime. The Nusime patent discloses an escalator assembly wherein a first end of the carrier is provided with a bed support which is in turn supported upon a bed formed as part of the building construction by a resilient mounting element which provides damping for vibration and the like passing between the escalator and building construction. A second end of the carrier is similarly provided with a bed support, which is supported upon a fulcrum firmly mounted to the bed. The fulcrum may be in the form of a bolt upon which the bed support is detented. Damping means may be incorporated into the fulcrum construction.
The present invention contemplates a novel method and apparatus for retrofitting existing escalator systems in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.
SUMMARY OF THE INVENTIONIt is an object of the present invention to provide a method and apparatus for retrofitting existing escalator systems in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.
More particularly, an object of the present invention is to provide a method for retrofitting an escalator installation of the character having a truss support member and a building structure member for supporting the truss support member, the method comprising the steps of: drilling a through-bore in the trust support angle member; drilling a through-bore in the building structure member; and passing an elongated securement member through the drilled bores.
Another object of the invention is to provide a method of the aforementioned character in which the building support member comprises an I beam and in which the securement member comprises an elongated length of cable.
Another object of the invention is to provide a method of the aforementioned character in which the building support member comprises a reinforced concrete support member and in which the securement member comprises an elongated, threaded bolt.
Another object of the invention is to provide a method as described in the preceding paragraphs which can be inexpensively accomplished by relatively unskilled workmen.
Another object of the invention is to provide a retrofitting method of the character described that can be accomplished without having to make any major modifications to the escalator installation.
Another object of the invention is to provide a retrofitting method as described in the preceding paragraphs that can be accomplished without having to shutdown the escalator installation for any extensive period of time.
The foregoing as well as other objects of the invention can be accomplished by the method and apparatus described in paragraphs which follow.
Referring to the drawings and particularly to
As will be described more fully in the paragraphs that follow, the methods of the invention concern various alternate approaches for retrofitting existing escalator systems of the character shown in the drawings in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.
One retrofitting method of the invention, which is illustrated in
Another retrofitting method of the invention, which is illustrated in
Still another retrofitting method of the invention is illustrated in
Yet another retrofitting method of the invention is illustrated in
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This latest retrofitting method comprises the steps of: attaching, as by welding, a first elongate bar 86 having a cross-bore 86a to the vertically extending leg “V” of the truss support angle member. Next, a second bar 88 having a cross-bore 88a is attached, as by welding, to the vertically extending web “W” of the building structure member “B”. This done, a threaded bolt 90 having first and second ends 90a and 90b is inserted through bore 86a and a second threaded bolt 92 having first and second ends 92a and 92b is inserted through bore 88a in the manner shown in
With the unique construction described in the preceding paragraph, angle member “A” along with bar 86 is movable horizontally relative to the I beam “B” to accommodate limited movement of the escalator relative to the supporting building structure during an earth quake.
Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.
Claims
1. A method for retrofitting an escalator installation having a truss support member and a building structure member for supporting the truss support member, said method comprising the steps of:
- (a) forming a through-bore in the truss support member;
- (b) forming a through-bore in the building structure member; and
- (c) passing an elongated securement member through said openings.
2. The method as defined in claim 1 in which the building support member comprises an I beam and in which said securement member comprises an elongated length of cable.
3. The method as defined in claim 1 in which said building support member comprises an I beam and in which said securement member comprises a threaded bolt.
4. The method as defined in claim 1 in which the building support member comprises a reinforced concrete support member and in which said securement member comprises an elongated, threaded bolt.
5. The method as defined in claim 1 in which the truss support member comprises an angle member having a horizontally extending leg and a vertically extending leg and in which the step of the method comprising forming a through-bore in the truss support member comprises the step of drilling a through-bore through said horizontally extending leg of said angle member.
6. The method as defined in claim 1 in which the truss support member comprises an angle member having a horizontally extending leg and a vertically extending leg and in which the step of the method comprising forming a through-bore in the truss support member comprises the step of drilling a through-bore through said vertically extending leg of said angle member.
7. The method as defined in claim 1 in which said building support member comprises an I beam having a connector plate affixed thereto and in which the step of the method comprising forming a through-bore in the truss support member comprises the step of drilling a through-bore through said connector plate of said I beam.
8. A method for retrofitting an escalator installation having a truss support member comprising an angle member having a generally vertically extending leg and a generally horizontally extending leg and a building structure member for supporting the truss support member, the building structure member comprising an I beam having an upper flange, a lower flange and a web member interconnecting said upper and lower flange, said method comprising the steps of:
- (a) forming a through-bore through a selected one of the generally vertically extending legs and the generally horizontally extending legs of the truss support member;
- (b) forming a through-bore through a selected one of the upper flange and the web member of the building structure member; and
- (c) passing an elongated securement member through said openings.
9. The method as defined in claim 8 in which said securement member comprises a threaded bolt.
10. The method as defined in claim 8 in which said securement member comprises an elongated length of cable.
11. The method as defined in claim 10 in which said elongated length of cable has first and second ends and in which said securement member further comprises a connector for interconnecting said first and second ends.
12. A method for retrofitting an escalator installation having a truss support member and a reinforced concrete building structure member for supporting the truss support member, said method comprising the steps of:
- (a) forming a through-bore in the truss support angle member;
- (b) forming a through-bore in the building structure member;
- (c) passing an elongated bolt through said opening in said building structure member; and
- (d) interconnecting said elongated bolt with said truss support angle member.
13. The method as defined in claim 12 in which said elongated bolt comprises a bolt having a threaded portion, and in which said method comprises the step of securing said elongated bolt to said building structure member using a nut threadably connected to said threaded portion of said elongated bolt.
14. The method as defined in claim 12 in which said elongated bolt comprises an eye bolt having an eye portion and a threaded portion, and in which said method comprises the step of passing an elongated cable through said eye portion of said eye bolt and through said bore in the trust support angle member.
15. A method for retrofitting an escalator installation having a truss support member comprising an angle member having a generally vertically extending leg and a generally horizontally extending leg and a building structure member for supporting the truss support member, the building structure member comprising an I beam having an upper flange, a lower flange and a web member interconnecting said upper and lower flange, said method comprising the steps of:
- (a) connecting a first elongate bar having a cross-bore to the vertically extending leg “V” of the truss support angle member;
- (b) connecting a second bar having a cross-bore to the vertically extending web “W” of the building structure member “B”;
- (c) inserting a first bolt having first and second ends through said cross-bore in said first elongate bar;
- (d) inserting a second bolt having first and second ends through said cross-bore in said second elongate bar;
- (e) connecting a first plate having an elongate bolt receiving slot and a drilled hole to said first ends of said first and second bolts; and
- (f) connecting a second plate having an elongate bolt receiving slot and a drilled hole to said second ends of said first and second bolts.
16. The method as defined in claim 15 in which said first and second bolts are threaded and in which said first and second plates are connected to said bolts by nuts connected to said bolts.
Type: Application
Filed: Aug 30, 2007
Publication Date: Mar 5, 2009
Inventor: Terryle L. Sneed (La Canada, CA)
Application Number: 11/897,709
International Classification: E04H 9/02 (20060101);