CA1172229A

CA1172229A - Skid for heavy machinery and method for constructing same

Info

Publication number: CA1172229A
Application number: CA000403647A
Authority: CA
Inventors: Howard G. Westerman
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-12-23
Filing date: 1982-05-25
Publication date: 1984-08-07
Also published as: AU8429182A; GB2089714B; AU547779B2; GB2089714A

Abstract

ABSTRACT

This invention provides a skid for heavy plant or machinery and a method of constructing same comprising fastening two rigid end assemblies (3,4) for the skid to a rigid framework having a base and two side walls. passing rods through the end assemblies so that the rods extend parallel to each other along the length of the framework, filling the framework with concrete. partially curing the concrete, un-fastening the end assemblies from the framework, remov-ing the concrete and end assemblies from the framework, completely curing the concrete, and tensioning the rods to stress the concrete between the end assemblies.

Description

2 2 ~
This invention relates LO a skid for heavy plant or machinery and a method of constructing same.
Such skids are used to facilitate transporta-tion, handling and positioning of plant or machinery and are usually forrmed entirely from rnetal parts such as steel or iron.
The present invention provides a skid for heavy plant or machinery and a method of constructing same wherein the skid is formed by fastening two rigid end assemblies for the skid to a rigid framework which, in turn, is comprised Or a base and two side walls so that the end assemblies form two wa]ls for the frame-work. Rods are passed through the end assemblies so that they extend parallel to each other along the length of the framework. The framework is filled with concrete and is allowed to partially cure after which the end assemblies are unfastened from the framework. The con-crete is then completely cured and the rods are tensioned to stress the concrete between the end assemblies.
The main advantage of constructing the skid in accordance with this method is that once the end assemblies have been formed the skid can be constructed as a complete unit in virtually one operation.
Preferably, to facilitate post-stressing of the concrete, each end assembly comprises a channel member. The channel members are fastened to the frame-work so that their bases are parallel (the rods being passed through the bases) and so that the channel of each member will receive concrete when the framework is filled to anchor the end plates to the concrete base of the skid.
Advantageousl~, each channel member has an end plate fixed to each of its ends; the plates on each channel rmember being parallel to each other and lying at right angles to the length of the channel rnember. A tube or the like runs parallel to the length of the channel member and is received through each of the end plates on a channel member. The tube strengthens ~' il'~22~
the end assel11bly constructio1l and also allows attach-ment ropes or chains to be pa.ssed through i t for tow-ing or lif~ing the sk;d.
PreEera~ly, each end assembly is Eastened to the side walls of the framework by its end plates during the construction of the skid.
Advantageously, to facilitate construction of the skid, the framework includes template members properly positioned for supporting anchoring ~neans for the machinery which is ultimately to be mounted on the skid. I`he anchoring means are so supported whereby they will be embedded in concrete in their desired positions when the Eramework is filled with said concrete.
Advantageously reinforcing members are arranged in the framework prior to filling it with concrete.
If the skid is to have a concrete pedestal, the framework may include means defining a mould for the pedestal whereby the pedestal and the remainder of the skid will be integrally formed when complete.
The concrete may be left in the framework until it is completely cured butin order to use the framework as frequently as possible to form additional skids, the end assemblies and the concrete base there-between are, with advantage, removed from the framework after only partial curing of the concrete.
To facilitate removal of the concrete base and associated end assemblies the walls of the frame-work is hinged outwards.
A more detailed description of the skid and method of constructing same in accordance with the present invention, will now be described, by way of exa~ple only, with reference to the accompanying draw-ings in which:
FIG. l is a plan view of a concrete skid produced by the method of the present invention;
FIG. 2 is a side elevation oE the skid of FIG. l;

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F`IG. 3 shows a section of the skid taken on the line A - A of FIG. l;
FlG. 4 shows a section of the skid taken on ~he line B - B of FlG. l;
FIG. 5 is a plan view oE a Eorm and template assembly for constructing the skid shown in FIGS. 1 to 4;
FIG. 6 shows a section of the form and tem-plate take~ on the line C - C of FIG. 5;
FIG. 7 is a scrap view of part of the form and template assembly shown in EIG. 6.
Referring to the accompanying drawings, skid of the present invention is shown in FIGS. 1 to 4 and comprises a substantially rectangular concrete base 1 having a central raised integral portion or pedestal 2 also formed from concrete near the midpoint thereof.
End plate assemblies 3 and 4, respectively, are affixed to base 1 at either end thereof.
Each end plate assembly 3, 4 is substantially identical in construction and comprises a channel member 5 of generally G-shaped cross-section. Each channel member is arranged along a respective shorter end of the rectangular base 1. Each end of the channel member 5 is welded to a respective one of two parallel side plates 6 and 7 with each of the plates 6 and 7 lying in a plane parallel to the longer side edges of the base 1.
Each side plate 6 and 7 is provided with an aperture 8 (see FIG. 3) for receiving a tube 9 which passes through the apertures 8 and is welded to the side plates 7. Each side plate also has two small apertures 130 the purpose of which will be explained below.
Extending through concrete base 1 and paral-lel to its longer side edges are six steel rods 10.
Each rod is sheathed in a plastic material to prevent any adhesion between the concrete and a respective rod 10. Each rod 10 is screw threaded at each of its ends ~ :~ 72229 131 to receive a hexagon nut ll.
Several reinforcing members are prov;ded in the CQIlCrete base 1. Eor example s-ixteen reinforcing bsrs 12 (see FIGS. 3 and 4) are arranged in the con-crete base 1 with the bars being equally spaced along the length of the base 1 and extending between its longer side edges and parallel to its shorter side edges.
That part of the base 1 to the left of the pedestal as shown in FIG. 1 is provided with two paral-lel angle members 17, each lying parallel to the longer side edges of the base 1. One limb of each angle is embedded in the concrete base 1. Lugs 18 are welded to the other limb of each of the angle mernbers 17 and that limb is also provided with three equi-spaced slotted holes 19.
Ihat part of the base 1 to the right of the pedestal 2 as shown in FIG. 1 is provided with a plurality of anchor bolts 20 which are embedded in the concrete of the base 1 with the end of the bolt within the concrete being bent over at right angles to the length of the bolt ~see FIGS. 3 and 4).
The pedestal 2 is also provided with a plural-ity of anchor bolts 21 which are similar in form to the anchor bolts 20 are likewise embedded in the concrete which forms the pedestal.
Extending between the longer sides of the pedestal 2 and parallel to its shorter side is a pipe 22, e.g. polyvinyl chloride, which is embedded within the concrete forming the pedestal.
The skid, as described, is used to support heavy plant. In a typical application, the four anchor bolts 20 arranged at the corners of a rectangle and provided on the far right hand side of the base 1 can be used to support a platform for a fuel container.
The two sets of four anchor bolts 20 arranged at the corners of a square in the base 1 and adjacent to the right hand side of the pedestal 2 can be used to support i 1'~222~
two compressor cylinders, and the two angle members 17 to the left of the pedeslal can be used to support an engine. The anchor members 21 on pedestal 2 can be used to support the compressor with pipe 22 providing a conduit through which a fuel pipe can be passed to connect the engine to the fuel container.
FIGS. 5 to 7 illustrate a form and template assembly for constructing the skid shown in FIGS. 1 to 4. This assembly is in the form of a jig indicated generally at 100 and is compr;sed of a steel framework.
The framework, in turn, comprises a rectangular base plate 101 the plate being made of appropr;ate material, e.g. carbon steel. Two elongate angle ~ars 102 are arranged on the upper face of the plate 101 along a respective longer side rnargin thereof. The free ends of each angle bar 102 is welded to the plate 101 (see FIG. 6). Arranged along each side edge of the plate 101 are four heavy duty strap hinges 103. One limb oE
hinge 103 is welded to the under side of plate 101 and the other limb is bolted to a respective side plate 104 which extend along the length of each side of plate 101.
Side plates 104 may be made from timber, as illustrated or from steel or other appropriate material.
The framework also includes a rectangular box-like structure which, in turn, is comprised of two side plates 105 and two end plates 132 which are welded together. Each side and end plate of the box-like structure is provided with a number of angle members 106 one face of each of which is welded to a respective plate 105 or 132 and the other limb of which extends outwardly from the plate at approximately 90.
Bolted alon~ the upper part of the outer side face of each plate 104 is a respective one oE two elongate angle members 107. One limb oE angle member 107 is bolted to side plate 104 and the other limb thereof extending outwardly at right angles to plate 104.
The outwardly extending limbs of the angles 106 are bolted to the outwardly extending limbs of the angles ~ `i 7 ~
l07 (see FIG. 6).
Also bolted to the elongate angle member 107 are three parallel angle members 108 which extend across the width of the jig and are provided with openings 109 corresponding in position to the slotted holes 19.
Iwo lurther angle rrlembers 110 are provided each of which have short angle 111 which are bolted to the members 107 (see FIG. 5). ~lat bars 112 are secured to each of ang:Le members 110. Both ~ars 112 and angle nlembers 110 are provided with openings ]13 which corrc~pond in po;ition to the desired position of the anchorin~ bolts 20.
Extending between the two ]onger plates 105 which form the aforesaid box structurc are four parll-lel angle members 114. Each o~ the angle members ll4 is provided with openings 115 corresponding with the desired position of the anchor bolts 21.
To form the skid shown in FIGS. 1 to 4 end plate assemhlies 3 4 are first bolted to the ends oF
the template assembly shown in FIGS. 5 to 7. That is achieved by bolting the side plates 7 of respective end plate assemblies 3 4 to the ends of the two paral-lel side plates 104. This is accomplished by using two plates 116 which are bolted to the plates 6 and 7 through the holes 130 and bolting the other end of the plates 116 to side plates 104.
Anchor bolts 20 and 21 are then inserted through the respective openings 113 and 115 in the angles 110 and 114 and in the cross plates 112 respectively.
Bolts 20, 21 are held in position by nut.s (not shown) screwed on their ends. Angle melllbers l7 are bolled to the angle members 108 by reg-istering the openings l()9 in them with the slot-like openings 19 ;n allgle Inerr.bers 17.
Pipe 22 is r)assed through ol)ening.q 13~ ([L(.
6) in the two longer plates 105 which Form ~he hox-like structure.

î 17222~
Rods lO are passed through the corresponding open;ngs in the channel members 5 until the;r threaded ends 131 protrude from the channel members. ~uts ll are then loosely screwed onto the threaded ends to hold rods 10 in position.
Reinforcing membcrs 12 are also placed at their predetermined positions in the jig. All the form and template pieces are lubricated to facilitate easy removal .
Concrete, WhiCil has a con.stitLIency reEerred lo in detaiI beIow is then poured into thc teml~]al-e asselïlbly. 'I'he tray-like base formed by the base p'late 101 the side plates lO4 and the channel mcmbers 5 of end-plaLe assemblies 3, 4 serve as a mould for forming the concrete base l of the skid whilc he box-like structure formed by the plates 105 and 13~ serves as a mould for forming the concrete pedestal 2. The con-crete is allowed to cure in the air at a temperature above 10 centigrade for a period of ~18 hours. The form and templates are then removed by unfastening the various bolts and hinging back the plates 104 as shown in FIG. 7. After removing the jig and ternplates the concrete base is stored on a pallet (not shown) or other suitable support and left for a period of 28 days.
At the completion of that period the nuts on the six rods lO are tightened until those rods are stretched in length by l/8 of an inch.
At this tensioning force the concrete is put into cornpressiorI at approximately 200 Ibs. pcr square inch. 1`his compression force is appl-ied so that I>ase can withstand deflection without cracking. As will be seen Erom FIG. 3 the tensioning force is apl)lied to Lhe concrete base l by each of Lhe channe'l melllbers 5 us the nuts on the bolts lO are screwed t;ght.
As an example of suitable dimelnsions for a typical skid, the length of the skid between the channel members 5 is about ll'6", the width of the skid is about

3'lO" as measured across the concrete base ] the height 222~3 of the concrete base 1 is about ~", and the height above base 1, of the central pedestal is about 8 7/~".
rhe length of each rod 10 is about 11'9", its diameter is 0.875", and each rod has a yield strength of about 55,000 lbs. per sq. inch.
An example of the constituency of the con-crete used in Forming the skid described and illustrated above is as follows: light aggregate 775.1 lbs., washed .sand 1,515 lbs., Portland type 1 cemenL 515.6 lbs., poGilith 15 oz., air 4.~ oz., water 220 lbs. The con-crete had a slup Lest of about 4", a seven day break oE 2,300 lbs. per sq. inch and a 28 day break of 3,500 lbs. per sq. inch.
The rnain advantage of a skid formed by ~he method of construction described and illustrated above ,is that the skid can be made in one operation, inc]ud-ing the pre-positioning and the casting in of the mount-ing rneans, e.g. the fixing bolts, and the easy attachment of the end assemblies with the towing bars formed by the tubes 9. The construction method also allows the skid base to be designed in such a way that the power unit mounted upon it is fully portable. The manner in which the concrete skid is constructed enables it to withstand point loads while the machinery mounted thereon is being transported or moved without damage or cracking of the skid.

Claims

The claims defining the invention are as follows:

1. A method of constructing a skid for heavy plant or machinery, the method comprising fastening two rigid end assemblies for the skid to a rigid framework comprising a base and two side walls so that those end assemblies form two end walls for the framework, pass-ing rods through the end assemblies so that they extend parallel to each other along the length of the framework, filling the framework with concrete, partially curing the concrete, unfastening the end assemblies from the framework, completely curing the concrete and tensioning the rods to stress the concrete between the end assemblies.

2. A method as claimed in claim 1, in which each end assembly comprises a channel member, the channel members being fastened to the framework so that their bases are parallel, the rods being passed through the bases, and so that each member receives concrete when the framework is filled.

3. A method as claimed in claim 1, in which each of the side walls of the framework is hingeable outwards to allow removal of the concrete and the end assemblies.

4. A method as claimed in anyone of claims 1, 2, or 3, in which the end assemblies and the concrete are removed from the framework after partial, and before complete curing of the concrete.

5. A method as claimed in claim 2, in which each channel member comprises an end plate fixed to each of its ends, the plates of each channel member being parallel, lying at right angles to the length of the channel member and receiving a tube lying parallel to the length of the channel member.

6. A method as claimed in claim 5, in which each end assembly is fastened to the side walls of the framework by its end plates.

7. A method as claimed in anyone of claims 1 to 3, in which the framework further includes template means for supporting anchoring means for the machinery, the anchoring means being so supported that they are embedded in the concrete when the framework is filled.

8. A method as claimed in anyone of claims 1 to 3, in which reinforcing members are arranged within the framework prior to filling it with concrete.

9. A method as claimed in anyone of claims 1 to 3, in which the framework comprises means defining a mould for a pedestal for the skid, the pedestal and the remainder of the skid being integrally formed.

10. A skid for heavy machinery comprising:
a rectangular base constructed of concrete;
an end plate assembly secured to each end of said base, each of said end plate assemblies being constructed of metal;
a plurality of rods extending through said base between and through said end plate assemblies, each of said rods being movable with respect to said concrete of said base;
and means at each end of each of said rods cooperating with a respective said end plate assembly to tension each of said rods to there-by stress the concrete base between said end plate assemblies.

11. The skid of claim 10 wherein said base includes:
a raised pedestal portion integrally formed of concrete on said base near the midpoint there-of.

12. The skid of claim 11 including:
means affixed in predetermined positions on said base and said pedestal protion and adapted to secure heavy machinery on said base.

13. The skid of claim 12 including:
a horizontal passage through said pedestal portion extending perpendicularly with respect to said end plade assemblies.