US2743966A

US2743966A - Oilless elevator guide shoe gib

Info

Publication number: US2743966A
Application number: US272107A
Authority: US
Inventors: John G Mckernan
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-02-18
Filing date: 1952-02-18
Publication date: 1956-05-01
Anticipated expiration: 1973-05-01

Description

y 1, 1956 J. G. MCKERNAN 2,743,966

OILLESS ELEVATOR GUIDE SHOE GIB Filed Feb. 18. 1952 INVENTOR. doh/r 6. Make/W417 ATTOENE This invention relates to improvements in wearing plates or gibs and particularly in guide shoes commonly employed in elevator construction, the primary object being to provide a guide shoe that is inexpensive to manu- I facture, long-lasting and virtually devoid of any structure or elements that would tend to cause difficulty in elevator operation.

United States Patent It is the most important object of the present inven- .tion to provide an elevator shoe that includes an elongated, U-shaped body of material that is highly wearresistant and provided with an internal cavity of the same cross-sectional configuration and provided with a filling capable of supplying a lubricant to the guide tracks of the elevator as the same is placed in use.

It is anzimportant object of this invention to provide "an elevator guide shoe wherein the material filling the "cavity as, above set forth, comprises graphite, the form and construction of the entire unit being such as to supply the lubricant to the guide track only as the material forming the main body minutely wears.

Other objects of this invention are to provide a guide shoe that requires no attention whatsoever over long periods of use; that is capable of lubricating the guide track upon which the same reciprocates without the necessity of periodic oiling; that cannot possibly become gummed or jammed during long periods of use on any originally oil or grease free, clean steel web; and that is capable of providing free sliding movement of the shoe relative to the guide track without undue power losses due to friction.

The guide shoe of the present invention is fully illustrated in the drawing wherein:

Figure 1 is an elevational view of an elevator guide shoe mounting with the oilless shoe gib of the present invention in place upon a guide track.

Fig. 2 is an enlarged, cross-sectional view taken in line II--II of Fig. 1.

Fig. 3 is a perspective view of the guide shoe, parts being broken away and in section for clearness; and

Fig. 4 is a cross-sectional view taken on line IVIV of Fig. 2.

Many attempts have been made to remove the difiiculties experienced by elevator service men in replacing and repairing the guide shoes forming a part thereof. Most notable in these attempts is the structure shown by U. S. Letters Patent No. 1,907,966, dated May 9, 1933. It was contemplated by the patentee thereof to provide a guide shoe made from material that includes graphite so that oiling would not be necessary. This patentee proposed to produce a molded guide shoe consisting of asbestos, graphite, and Bakelite, the asbestos providing the body, the graphite serving to lubricate the guide track and the Bakelite being used as a binder.

Through many years of experience I have found that a guide shoe made in accordance with the aforesaid patent is satisfactory only when the guide track is constantly provided with a liquid coating of a suitable composition for preventing gumming and binding. Interlee mixing of the graphite within the material forming the main body of the guide shoe apparently causes a gumming that prevents free sliding of the shoe on the track, thereby necessitating the use of substance to dissolve the gummed material.

Furthermore, it has been found that guide shoes such as forms the subject matter of the aforesaid patent, while having many advantages, are not particularly longlasting and for that reason there is a need for a guide shoe that can be used for a considerable period of time without need for replacement or other attention whatsoever. These features are included in the guide shoe illustrated in the drawing and in Figs. 1 and 2 thereof, there is shown fragmentarily, a portion of any conventional elevator broadly designated by the numeral 10.. I

A plurality of brackets are normally provided on elevator it one of which is shown in Figs. 1 and 2 and designated by the numeral 12. Bracket 12 in turn receives a stem 14 having a guide shoe mounting means 16 thereon. A guide shoe 13 forming the subject matter of the present invention is held in place within the mounting 16 by end plates 19 in partial embracing relationship to web 29 forming a track for guiding the elevator. 10 in its vertical reciprocation.

The shape of the guide shoe hereof is conventional and as shown in Fig. 3, the same is elongated and U-shaped in cross-section, there being a bight 22 and a pair of side 'walls 24 all coextensive in length, the walls 24 being joined to the bottom wall 22 as by provision of removable c'ross-pins 26. A U-shaped cavity intermediate the ends of the shoe 18 and having

portions

28 and 30 formed in bight, 22 and side walls 24 respectively, receives afilling 32 0f material. capable of lubricating the web 20 as the shoe 18 'reciprocates therealong. Notche's 34 in walls 24-24 receive correspondingears 36Jon'plates 19 for holding shoe 18 in place.

In the initial manufacture of shoe 18 the thickness of the filling 32 is preferably the same as the depth of the cavity 2830. Any suitable material may be used in the production of the primary walls 22-24 of the shoe 18, but it is essential to the proper operation of the shoe hereof that such material be highly resistant to Wear as the shoe 18 reciprocates along the guide web 20.

There are many suitable materials on the open market made synthetically and including layers of canvas that are steeped in liquid plastic and thereupon subjected to high pressure. has proved highly satisfactory, the plastic being preferably a phenol formaldehyde resin. Such product is produced by a number of manufacturers utilizing essentially the materials above set forth and following substantially the same steps of manufacture. Examples of trade names now being employed by such manufacturers areSynthaneMicarta-Textolite and Formica. The substance that constitutes the filling 32 is preferably pure graphite Whether in the natural state as mined or artificially produced, the lubricating properties of such material being well known.

When the shoe 18 is placed in use, the inner surfaces of the

walls

22 and 24 will quickly becomesrnooth and therefore, freely slidable on the web 20. Because of the high wearing qualities of the material forming the main body of the shoe, the depth of cavity 28-3t), becomes less only gradually and progressively and the graphite filling 32 accordingly wears away and deposits on the Web 29 only as fast as the

walls

22 and 24 wear away. It has been found that only a small amount of the graphite 32 will be deposited on the web 2% even after long continuous use but that such deposit is sufiicient to lubricate the web 20 and the walls 22-24, and thereby reduce friction, provide for smooth sliding of the shoe 18 on Patented May 1,

A laminated phenolic canvas base material 3 the web 20 andreduce the amount of wear of the

walls

22 and 24.

The wearing away of the

walls

22 and 24 is very slight since the lubricating material immediately polishes the walls of the shoe, and indirectly through the shoe, the web 20. Further Wear is thereupon reduced to a minimum.

A tremendous advantage in using a shoe of this character as above indicated lies in the fact that the shoe itself, as well as the web 20, does not become gummed and clogged with the lubricating material 32, provided only that the entire web 20, as well as the shoe itself, is kept free of grease, oil and other foreign matter. It has been found further that a shoe of this character may be used over exceptionally long periods of time without need of replacement or any attention whatsoever, unless by some defect in other structural parts of the elevator assembly, grease and oil become deposited on the web 20.

Another advantage lies in the fact that it is absolutely unnecessary to use any material whatsoever on the web 20 to provide for the free sliding movement of the shoe 18 thereon. The costs of the shoe 18 are no greater than those now in common use by virtue of the fact that the shoe hereof is long-lasting and virtually trouble free; a tremendous saving in elevator operation and maintenance is presented.

Elevator guide shoes wear unevenly. Thus by provision of three separate sections 22-24-24, any one section may be replaced by removal of and reinsertion of pins 26. Further, such multi-sectional construction reduces cost of manufacture by making the formation of cavities 28 30-30 easier.

While materials other than those above enumerated may be utilized in the production of the shoe herein set forth, it is appreciated that the primary principle hereof lies in the embedding of a lubricating material Within the main body of the shoe and covering an area that is appreciably less than the over-all efiective area thereof and in the utilization of highly wear-resistant material in production of the main body of the shoe itself.

Accordingly, such changes as fairly come within the spirit of this invention as defined by the scope of the appended claim are contemplated hereby.

Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is:

An oilless elevator guide shoe comprising an elongated, U-shaped body having a bight and a pair of side walls each initially separate from said bight, and each having an outermost, longitudinal edge, there being a single, polygonal cavity in the inner face of each side wall respectively and in the inner face of said bight intermediate the ends of the body, the cavity in the bight spanning the distance between the side walls and communicating with the cavities in the side walls, the cavities of the side walls being open along corresponding edges, extending from said edges to the cavity in the bight, and being coextensive in length with the latter, the lengths of the cavities being appreciably less than the length of the body, and the ends of the cavities being closed; a plurality of pins releasably connecting the side walls with the bight; and three separate, fiat, interengaging, solid plates of pure graphite, each completely filling one of said cavities, the plates being fiush with said inner faces of the bight and the side walls, presenting a U-shaped bearing surface extending through a portion of the length of the body, said body being of laminated canvas, steeped in phenol formalde' hyde resin and subjected to high pressure, rendering the same appreciably more resistant to wear than said graphite plates.

References Cited in the file of this patent UNITED STATES PATENTS 1,002,514 Hatfield Sept. 6, 1911 1,249,920 Doehler Dec. 11, 1917 1,907,966 Henry May 9, 1933 2,045,620 Spullies June 30, 1936