MXPA97000205A - Rompi screw assembly - Google Patents

Abstract

The present invention relates to a breakable screw assembly comprising: a shank member comprising a body of the elongated shank and a head of the shank, the body of the shank having a proximal end and a distal end, the proximal end of the body of the tang having a plurality of grooves transverse to the length of the groove body, and spaced apart from one another, the body of the dowel having external threads along a length portion at the distal end thereof; of the collar member having proximal and distal ends, the body of the collar member having an internal passage for receiving the distal end of the shank body, and being understandable about the shank body, and the distal end having a length portion which is used inwardly for a predetermined length of the body of the collar member, a threaded recess member having an internal passage for to receive the distal end of the body of the collar member, the inner passage having a mouth opening to a first portion of length that is used inwardly of said mouth, and a second length portion having internal threads that coincide with the external threads of the shank body of the shank member, the first length portion engaging the tapered length portion of the body of the collar member to be secured on the body of the collar member and the spindle member.

Description

BREAKABLE SCREW ASSEMBLY BACKGROUND OF THE INVENTION 5 Field of the Invention The present invention relates to a breakable screw assembly, and particularly, but not limited to, a breakable screw assembly especially useful for securing a slider to a hanging support. standard truck bolt screw has a diameter of 0.9525 centimeters (3/8") and 2.54 to 5.08 centimeters long.This is a steel bolt.The upper edge of the muzzle has mounting holes to receive the bolt. lodera is insured to a hanging support that is attached to the truck by mounting the screws through the slider and through the holes in the hanging support. Standard hexagonal head screws and hand or power tools are required to mount the slider to the hanging support. 20 It is important that the bolt be strong enough to support the lumber, which is usually 1/2"(1.27 cm) thick.The hanging support is typically made of steel or formed from steel in welded iron rods. The average loderas weighs approximately 4,536 -. 25 - 13,608 kilograms, and in use, as many as 45.36 kilograms of snow and ice can accumulate in the hillside. This puts substantial stress on the screws. In addition, the screw assembly must also withstand the forces associated with torsion, rotation, vibration, as well as the forces associated with the downward tension. In addition, significant tension is placed on the sloop when the truck travels at speeds of 88.5115 - 96.558 kilometers per hour. The mounting orientation of the shed is altered by these forces, and is prone to more serious damage. < > 'Specifically, a critical stress occurs on the orchard when a truck reverses over a crooked hillside. When this occurs, the lobe is usually torn off from the hanging support, the mounting holes of the lobe can be destroyed and, therefore, the driver can no longer use the locker until it is repaired or replaced, which can be time consuming and expensive. Frequently, the hanging support is also destroyed. On the other hand, you can not use an aluminum screw with a zero-hanging support because a galvanic reaction will occur between the two metals. Even if 0 steel screws are used with a steel hanger, the steel screws are oxidized by moisture and severe external conditions, thereby deteriorating the screw. The screws are damaged in the threads by impact with rocks, or often adheres chapopote to the screw. Making 5 difficult or almost impossible to remove the screw.

Prior Art The following are relevant to the present invention: Patents of the United States of North America Numbers 3,258,887 to Mostoller; 2,826,428 to Lincoln; 3,778,086 to Oore et al; 3,822,897 to Heath; 3,158,386 to Tillinghast; and 3,695,215 to Black. The Mostoller patent discloses a screw designed to separate from the fasteners and materials to which it is attached, in the event of an explosion. Specifically, the Mostoller screw comprises a standard screw with a single rod reduced in a portion of the shaft and is designed to fall off after a sudden force, pulling the screw. The Lincoln patent describes a replaceable fender, characterizing a wing nut, which can be installed by hand, but usually requires a tool to be removed. This device makes no provision to prevent damage to the hanging support if the shed is subjected to large amounts of shear forces. • The Moore patent discloses a mount assembly element, characterizing a screw-loaded fastener, which is designed to open when a downward tension occurs, releasing the lodger without any damage. A problem with this device is that it is easily exposed to the elements and is susceptible to damage by the chapopote, the stones, the dust and sandstone. The solution provided by Moore's patent, like many others in the industry, requires special hanging brackets, fasteners, hinges, springs, etc. Consequently, this is a very expensive solution compared to standard screw assemblies. Heath's patent describes a perforated mulch that will separate after a certain stress has been reached when the truck reverses over the sloop. The perforations reduce the resistance of the shed to about 1/5 of the standard shear, which is 135.63 Joules of shear. Unfortunately, the concept is impractical because 135.63 Joules of shear force are reached almost immediately, when a tire is reversed on a slope. The Tillinghast patent discloses a specially designed slotted slider bearing and clamping device that will allow the slider to be released from the hanging support before damage to the slider occurs. If this occurs satisfactorily, the user must remove the screw mounts to reinstall the slop. The designs of the assemblies and the materials used are subject to corrosion and damage on the road, which would make reassembly a problem. Consequently, the device has not been well accepted in the industry.

Black's patent describes a perforated weakened lobe, which is designed to be torn off in sections if it is passed over it. This makes it possible to use the same lobe more than once, if it is passed over it, but the remaining lorero is smaller than before. The deficiencies in the attempts of the prior art are clear. There is a need to provide an inexpensive screw assembly for mounting and repairing the standard lumber assembly, without requiring hangers, tools, fasteners and the like. COMPENDIUM OF THE INVENTION The present invention is directed to a screw assembly made of a hard plastic material, which will not rust or corrode, and which allows the screw assembly to have a high modulus of elasticity. The screw assembly comprises a shank member, a collar member and a butterfly knob member. The pin member is designed to break when subjected to a shear force greater than a previously determined amount. Specifically, the shank member characterizes a shank body and a round head of the shank, the shank body having a portion of proximal length adjacent to the head of the shank, which has multiple splines transverse to the shank body . The diameter of the body of the spike of the stria closest to the head of the spike is smaller than that of the more distant splines.

Consequently, the tang member will break in the closest groove, when subjected to a shear force greater than a previously determined magnitude. The objects and advantages of the present invention will become clearer when reference is made to the following description, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view separated into parts of the screw assembly, in accordance with the present invention. Figure 2 is an elongated side view of the shank member of the screw assembly. Figure 3 is a cross-sectional view taken along line 3-3 of the butterfly knob member shown in the assembly of Figure 1. Figure 4 is an end view of the collar member. Figures 5A, 5B, 5C and 5D are partial cross-sectional views of the screw mounted through a slider and a hanging support, and illustrate the different stages of the screw assembly under tension. Figure 6 is an elongated side view of the spike member supporting a downward force, just before breaking. Figure 7 is a view of the rack and the hanging support through which the screw assembly is mounted. Figure 8 is a perspective view of a mounted loader that is subjected to forces that are insufficient to break the shank member. Figure 9 is a perspective view of a mounted loader that is subjected to forces that are sufficient to break the shank member. DETAILED DESCRIPTION OF THE PREFERRED MODE Referring to Figures 1-4, the screw assembly is generally shown at 10, and comprises a tang or shank member 12, a collar member 14 and a butterfly knob member or nut member 16. Generally, the collar member 14 is inserted over the end of the shank member 12, on the opposite side of a slider hanging support, and the butterfly knob or embedment member 16 fits over the collar member 14 and the spigot member 12. The spigot member 12 is custom made for the standard screw diameter of 0.9525 centimeters (3/8"), although this can be custom made to any diameter. a head 18 and a body 20, having a proximal end 22 and a distal end 24. Preferably the head 18 is round because no tools are needed to mount and tighten the screw assembly. They are arranged along a portion of length 26 at the distal end of the body 20. The threads preferably have a 30-degree inlet without thread relief. An alternative series of ridges (channels) and ribs is provided along a length portion 28 toward the proximal end of the body 20. Specifically, four ribs 30 are provided, which are separated by channels 32A, 32B, 32C and channel 34. Ribs 30, which are preferably made to measure for the standard screw diameter of 0.9525 centimeters (3/8") ), provide protection for the channels 32A, B, C. The channel 34 is closer to the head 18. The diameter of the body in the channel 34 is preferably smaller than the body diameter in the channels 32A, 32B and 32C , and the body diameter in the channels 32B and 32C may be smaller than the diameter in the channel 32 A. Specifically, the channel 34ma near the head 18 is preferably designed to be the weakest point of the spigot member 12. This is also the point in the screw assembly, where the tension and the largest shear forces are transferred to the last.In addition, the ribs and channels of the spigot member 12 are made to order and positioned in such a way that the member of is pin 12 will be torn off or broken in channel 34 when subjected to a downward force or shear force exceeding a predetermined threshold. Later on, this will be explained in more detail. The quantity and size of ribs and channels may vary according to the particular application of the screw assembly. For example, to attach a typical 1.27 centimeter (1/2") heavy rubber truck mudguard, four grooves and four ribs are provided on the preferred 0.9525 centimeter (3/8") screw. In a preferred design, the channels must be adjusted to the following dimensions. In the fourth most distant channel of the head, the diameter of the body of the spike preferably should be approximately 0.41148 centimeters, the diameter of the body of the spike in the third and second channels should preferably be approximately 0.3937 centimeters and the diameter of the channel closest to the head should preferably be approximately 0.37592 centimeters. In another channel design, the diameter of the spindle body in all three channels farthest from the head should be approximately 0.6096 centimeters and the diameter of the channel closest to the head should be approximately 0.5588 centimeters. Yet another example of a suitable spike design is one that has the channels farthest from the head with a diameter of approximately 0.4953 centimeters, and the channel closest to the head being approximately 0.44958 centimeters in diameter. In general, the channel closest to the head of the spike must have a diameter which is approximately 5-10 percent smaller than the diameter of the farthest channel of the head. Concentrating now on the collar member 14 shown in Figures 1 and 4, the collar member includes a generally cylindrical body 40 having a proximal end face 42 and a distal end face 44. An internal passage 45 extends as far as possible. length of the body 40 and tailored to receive the shank member 12. Further, a portion of the collar body adjacent the distal end 44 includes a portion of length 46 that is tapered preferably approximately 15 degrees inward toward the Distant end 44. In addition, the collar member includes three slots 50, 52 and 54 that extend the entire length of the body 40. The slot 54 is the widest and also passes completely through the collar wall to the internal passageway. 45, and is designed to make the collar member 14 compressible. The slots 50 and 52 are relief grooves that are not as wide as the slot 54 and do not pass completely through the body 40. Slots add compressibility and also contribute to a bolt feature, which will be explained later in this. By way of an example, in which the collar member has an outer diameter of approximately 0.9906 centimeters, the slot 54 is approximately 0.254 centimeters wide, while slots 50 and 52 are only 5 approximately 0.1016 centimeters wide and approximately 0.2286 centimeters deep. The slots 50, 52 and 54 are offset from one another by an angle of approximately 120 degrees. As will be more apparent later in the present, the collar member 14 provides a lateral force against the butterfly knob or recess member 16 and the hanger bracket, to resist loosening of the screw assembly caused by vibration, torsion, rotation and shouting The member of collar 14 also provides additional support for the body 20 of the spike member. In use, the collar member is • * "•" "secures inside the butterfly knob or embedment member 16, and protects the body of the spike member from external corrosive effects. 20 Turning now to Figures 1 and 3, the member of the spike member will be described in more detail. butterfly knob 16. The butterfly knob or embedment member 16 comprises a body 60 circumscribing an internal passage 62. The internal passage 62 is opened in a tapered mouth 64 that is tapers inwardly to, preferably, about 15 degrees for a length portion of the inner passage, which is designed to correspond to the tapered portion 46 of the collar member 14. The next portion of length 66 of the internal passage is straight, and the end length portion 68 is threaded onto the end of the butterfly knob or embedment member 16. The threaded length portion 68 is designed to correspond to the external threads 26 of the spigot member 12. Grip ribs 70 are provided. , "and indentations 72 at the end of the butterfly knob or the embedment member 16, to facilitate rotation and tightening of the butterfly knob or embedment member 16 around the spigot member 12. All the screw assembly It is preferably made of a specialized molded resin material called Nylatron GS-21, which is manufactured by The Polymer Corporation, and sold under the trademark name POLYPENCO. This material is the molded resin version of the Nylatron GSM, which is a cast nylon. The Nylatron GS-21 molded resin consists of a base material of 6/6 nylon, 0 molybdenum disulfide and carbon black. In addition, molybdenum disulfide is present as finely divided particles that are uniformly distributed throughout the resin. This reduces the coefficient of expansion, water absorption and shrinkage, to provide better overall dimensional stability than other unmodified resins. Carbon black is added for protection against ultraviolet light. The manufacturer maintains the actual quantities of the components as reserved data of industrial processes. INVENTORY OF THE PHYSICAL PROPERTIES OF THE NYLATRON (GSM / GS-21) ISSUE DESCRIPTION ASTM UNIT NYL? TRON GS-21 1 RESISTANCE? THE VOLTAGE D638 I SI 1 3.250 2 STRETCHING D638% 12 3 MODULE? L? TENSION D638 PS1 600,000 4 RESISTANCE TO CUTTING EFFORT D732 PSI 10,000 5 FLEXIONAL RESISTANCE D790 PS1 16,500 (DEFORMATION) 6 FLEXIONAL MODULE D790 PSI 475,000 7 ROCKWELL HARDNESS D785 R / MI 19/85 * 8 DEFORMATION UNDER A LOAD OF 2000 D621% 1.35 PSI- 50 ° C COMPRESSIVE RESISTANCE D695 PS1 12,750 * 10 TEMP. DEFLECTION OF ZERO FER. D648 op 210 (264 PS1) 1 1 FUSING POINT D789 op 489 12 EXPANSION COEFFICIENT A * D698 or 2.7 LINEAR THERMAL B * D698 op 3.6 13 IMPACT TO TENSION DI 822 90 FEET. LBS. BY PULG.CU ?. 14 SPECIFIC GRAVITY D792 1.16 15 WATER ABSORPTION D570% 1.10 SATURATION 24 HRS. D570% KO 16 FLAMMABILITY D635 1N MIN? UI? EX '? NGUIBLE MUES I RA 1/4 X 1/2 * ~ "r- 17 LINEAR SHRINK -LINE .007 / .017 1/16 TO 1/4 IN / IN NOTE: (A) = -6.666 ° CA -58.333 ° C (B) = -12.22 ° CA -106.66 ° C 5 A list of the properties of the Nylatron material that is preferably used in accordance with the present invention is established above. Other materials that have similar properties can also be used.The material described above of the 0 screw assembly allows for a slow rate of wear, a low coefficient of friction, no risk of corrosion, low exposure to damage from road hazards and none Galvanic action or oxidation In the present invention, alternative materials may be used that meet, or are close to, the prescribed specifications, although these may not provide all the advantages of the preferred material Nylatron GS-21. Referring now to Figures 5A- 5B, 6 and 7, the operation of the screw assembly 10 will be described in order to mount a slider 80 to a hanging support 82. In figure 7 the slider 80 and the hanging support 82 are shown in perspective view. The hanging support 82 comprises mounting tabs 94 having holes 86 for receiving a mounting screw. The slider 80 has multiple holes 88 in same, also to receive a mounting screw.

Typically, there are four holes per shed, but this may vary. The shank member 12 is passed through the slider 80 and the hanger 82. The collar member 14 is placed over the end of the shank member and pushed tightly against the rear side of the hanger 82. Then, it is placed the butterfly knob or embedment member 16 on the exposed end of the shank member 12, and on the tapered end of the collar member 14. The internal threads of the butterfly knob member 16 are eventually engaged with the external threads of the limb member. spigot 12, and the butterfly knob member 16 can be tightened by hand around the collar member 14 and the spigot member 12. When the butterfly knob member 16 is rotated about the spigot member 12, the taper 64 in of the butterfly knob member 16 pushes on the taper 46 of the collar member 14. Due to the slots 50, 52 and 54, the collar member 14 compresses on the spigot member 12 and secures the assembly tightly in place. The tensile force of the collar member to expand ensures the collar member in place, and dampens any vibration in the assembly. This assembly, once secured, is immune to swelling and contraction, and the opposing forces of the collar member compressed against the head of the spigot hold the assembly tight and 'stable. In addition, the screw assembly can be installed and removed easily by hand, without the need for any help or mechanical tools. In summary, there are two forces that make the screw assembly stable and strong. The first 5 is the lateral force between the collar member 14 and the head of the spigot 18. The second is the expanding force of the collar member 14 against the butterfly knob or the embedment member 16 and the compression force of the collar. '> collar member 14 and rod body 20. Once the screw assembly is secured, the screw is designed to support a predetermined threshold of shear force, and once that threshold is exceeded, the shank member will break. 12. Specifically, referring to Figures 5B, 5C, 5D and 6, the arrow F 5 represents a resultant downward or cutting force on the tang member. This force is the result of a twisting or rotating movement of the lobe, and also in particular, by the occurrence of the lobe being trapped in an adjacent wheel turning (Figures 8 and 9). The grooved structure 0 of the dowel member and the nature of the assembly material allows the dowel member to bend and absorb the shear force F. This is shown in Figures 5B and 5C. However, when the shear force F exceeds a predetermined threshold, such as 500 Newtons (N), the screw is designed to break in channel 34.

# Specifically, the screw is designed in such a way that the fluted structure transfers the force first to the more distant channel shown at 32A in Figure 6. This portion of the spigot member 12 will begin to bend at a predetermined force, such as like 415 Newtons. As the bending force on the screw increases, the next channel 32B will begin to bend when the transferred force exceeds a threshold, such as 375 Newtons, upon which the force will be transferred to the next channel 32C.

The forces transfer to the nearest channel 34, until the near channel 34 is subjected to more than a shear force of the threshold. As the shear force approaches this threshold, the more distant ridges will collapse against each other, in such a way that their lower edges interlock with each other, as shown in point E in Figure 6. This restricts an additional bending of the screw and, therefore, '"- so much, it transfers the larger cutting force to the upper part of the shank member and the head of the shank at the union of the screw body and the head of the shank. the shear force is greater than, say 500 Newtons, the screw will break in the groove 34, as shown in Figure 5D. The particular level of shear force that will break the screw depends on many design factors, including the number of grooves, the dimensions of the grooves, the diameter of the screw, and so on. A screw with a diameter of 0.9525 centimeters (3/8") having the diameters of grooves specified above, for mounting slopes, is preferably designed to break into the closest groove 5 to approximately 500 Newtons. The spike may be designed to transfer forces differently, and therefore have a different breakthrough threshold, for example, the splines may have stepped diameters, such that the diameter of the spike body of the more distant splines it is larger (in a graduated manner) than the diameter of the proximal grooves Figure 8 illustrates the movement of the shearer in the event that the shear force on the shank member 12 does not exceed its breaking threshold. the lobe and the hanging support can be flexed to a point B, but insufficient force on the spike member will prevent the latter from breaking. It will not loosen from the hanging bracket, and the whole assembly will eventually return to its normal position shown in N. 0 However, as shown in Figure 9, if the looper is pulled, for example, under a rim by rotating, then it is very likely that the pin member will be subjected to a shear force greater than the breaking threshold, upon which the pin member will break, and the heads of the pins of one or more screws of their pins will be loosened. respective screw bodies. However, holes in the lodge will not be broken because the screw assembly will break before enough force is applied to the lodge. This is beneficial because it is much less expensive to replace a 5-bolt assembly than to repair or replace a slop or a hanging rack support. The screw assembly according to the present invention has been described with particular utility for mounting a slider on a hanging support. Nevertheless, It should be understood that the screw assembly can have many other uses, particularly where it is desirable for a screw to break when a shear force at the joint of the pin and the head of the pin is greater than a previously determined amount. Modifications can be made to flutes, to the dimensions of the spike and to the degree of tension of the material, so that it is suitable for applications / "- Particular The screw assembly of the present invention is particularly useful for mounting slopes due to the need to avoid damage to the slopes and lor. pendants if they are subjected to large forces in the mounting screw. It should also be understood that the description and the foregoing drawings should be considered only illustrative of the principles of the invention. Since those Many modifications can easily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation that was shown and described and, accordingly, all modifications and suitable equivalents can be considered to fall within the scope of the invention. the invention.

Claims (19)

1. A breakable screw assembly comprising: a shank member comprising a body of the elongated shank and a head of the shank, the shank body having a proximal end and a distal end, the proximal end of the shank body having a plurality of grooves transverse to the length of the groove body, and spaced apart from one another, the body of the peg having external threads along a length portion at the distal end thereof; a body of the collar member having proximal and distant ends, the body of the collar member having an internal passage for receiving the distal end of the body of the shank, and being compressible around the body of the eepiga, and the dieting end having a portion in length tapering inwardly for a predetermined length of the body of the collar member; a threaded recess member having an internal passage for receiving the distal end of the body of the collar member, the inner passage having a mouth that opens to a first portion of length that is tapered inwardly of said mouth, and a second portion of length having internal threads coinciding with the external threads of the tang body of the shank member, the first length portion engaging with the recessed length portion of the body of the collar member to be secured on the body of the collar member and member of spike.

2. The screw assembly of claim 1, characterized in that the shank member, the body of the collar member and the threaded recess member are each made of a molded resin material.

3. The screw assembly of claim 2, characterized in that the resin material is Nylatron GS or

4. The screw assembly of claim 1, characterized in that the collar member comprises at least one longitudinal groove extending from the proximal end to the die end

5. The screw assembly of claim 4, characterized in that the collar member includes first, second and third longitudinal grooves, positioned at angularee positions previously determined on the collar member, The first longitudinal groove extends the length of the collar member and through the internal passage, and the second and third grooves extend the length of the collar member and each has a depth less than that of the first groove. of screw of claim 1, characterized in that the diameter of the body of the spike in the groove closest to the head of the spike, and s smaller than in the more distant ridges, in order to define a breaking point at which the shank member will break when subjected to a shear force greater than a predetermined breakthrough threshold, whereby the member The bead is bent to a length portion occupied by said plurality of grooves, in response to the shearing force, and breaks at the nearest groove when the shear force on the spike at the nearest groove "- exceeds said breakthrough threshold. determined previously. 7. A breakable screw assembly comprising: a shank member comprising a body of the elongated shank and a head of the shank, the shank body having a proximal end and a distal end, a portion of proximal length of the body of the shank. the spike 5 being flexible in response to the shearing force, and in response to a shear force greater than a certain amount ^ - previously, the body of the pin breaks at the junction of the body of the pin and the head of the pin, the body of the pin having external threads along a portion of 0 length at the distal end thereof; a collar member having a generally cylindrical body with proximal and distant ends, and an internal passage for receiving the distal end of the shank body, the collar member being compressible about the shank member; an embedding member having an internal passage for receiving the distal end of the collar member, and the distal end of the shank member, and for compressing the collar member around the shank member, the inner passage having a first portion of length with internal threads coinciding with the external threads of the tang body of the dowel member, the proximal length portion of the dowel body comprising a plurality of grooves transverse to the body of the dowel and spaced apart from each other. The screw assembly of claim 7, characterized in that the embedment member comprises a second length portion engaging the tapered length portion of the collar member to be secured on the collar member and the shank member. The screw assembly of claim 8, characterized in that the second length portion of the embedment member is tapered towards the outside. The screw assembly of claim 7, characterized in that the diameter of the shank body of a spline closest to the head of the shank is smaller than the diameter of the shank body of the other splines. 11. In combination, a frangible screw assembly for mounting a heavy object from a base support, the frangible screw assembly comprising: a break dowel member having an elongate pin body with a proximal end and a distal end, and a head of the shank at the proximal end, a portion of proximal length of the shank body adjacent to the head of the shank being breakable when subjected to a shear force greater than a previously determined amount, said shank break member inserted to through the base support and the heavy object, in such a way that the distal end and the head of the spike are on opposite sides of the base support and the heavy object, a compressible collar member having an internal passage to receive the distal end of the spike member and being compressed around the spike member; an embedding member having an internal passage to receive the distal end of the collar member, and engaging an outer surface of the collar member, to compress the collar member around the spike member and counteract the expansion forces of the collar member, said embedding member also comprising elements for attachment on the shank member, and for applying a longitudinal force between the head of the shank and the collar member to secure the heavy object to the base support, the proximal length portion of the shank member comprising a plurality of grooves that are transverse to the body of the peg and are spaced from one another. The combination of claim 11, characterized in that the shank member includes a portion of threaded length adjacent to the distal end, and characterized in that the elements for attaching the butterfly knob member comprise a portion of threaded length • "to coincide with the threaded length portion of the spike member 13. The combination of claim 11, characterized in that the diameter of the spindle body in the spline closest to the head of the spike is smaller than in the spline. 14. The combination of claim 12, characterized in that the internal passage of said embedding member comprises a mouth receiving the tang member, and portions of first and second length, the first portion of length being threaded, and the second 'portion of 20 length being adjacent to the mouth and being tapering towards the inside of the mouth. The combination of claim 14, characterized in that the collar member has a length portion adjacent to the distal end, which is tapered towards 25 inside for a previously determined length of the same, and which is engaged by the first and second tapered length portions of the embedment member, for compression by the butterfly knob member. 1

6. The combination of claim 11, characterized in that the heavy object is a slider, and the base support comprises a hanging rack support which is rigidly attached to a truck. 1

7. In combination with a mounting member supported by the vehicle, positioned rearwardly and on a land wheel assembly of the associated vehicle, the mounting member, defining an upright wheel slider mounting portion, extending transversely to said vehicle and having a generally horizontal perforation extending from the front back formed through the 15 same, a portion of wheel tread generally vertical having a top margin placed behind the portion of "" "assembly, and provided with an opening extending from the front back formed therethrough, recorded with the perforation and a separate lower margin 20 behind the wheel assembly, a screw assembly for securing the top margin to the mounting portion, said screw assembly including a body of the elongated shank passing through the bore and the opening, and having a proximal end and a distant end, a head 25 of the shank at the proximal end rearwardly of said upper margin, the proximal end of said shank body having a plurality of ribs traneverealee to the length of the shank body and spaced apart from one another, to define breaking points in which the shank member will be broken when subjected to a shear force greater than a predetermined shattering threshold, the shank body having external threads along a length portion at the distal end, an embedment structure threaded in the length portion and positioned forwardly of the mounting portion, and threaded along said length portion toward the head of the dowel, to hold the upper margin to the mounting portion, with the grooves under a force of tension greater than the portions of the pin between the grooves and the grooved portions of the pin working to distribute lateral bending forces on said spike along the length thereof. 1

8. The combination of claim 17, characterized in that the diameter of the spike body in the groove closest to the head of the spike, is smaller than in the more distant ridges. A screw assembly for securing a top margin of a slider, having a horizontal opening formed therethrough, to a vehicle mounting portion having a horizontal perforation therethrough, with which said opening is recorded, a shank member comprising a body of the elongate shank having a proximal end and a distal end, a head of the shank at said proximal end, said proximal end of the shank body having a plurality of serrations transverse to the length of the body of the shank. the spike and separating from one another, the diameter of the body of the spike in the groove closest to the head of the spike being smaller than in the more distant ridges, the body of the spike being adapted to extend along the length of the spike. the opening of the perforation, with the head of the shank opposite the coefficient of the euperior margin away from the mounting portion of the vehicle, the body of the teni teni Endo external threads along a length portion at the distal end, said length portion being adapted to have an embedment assembly including a threaded bore formed therethrough, threaded therein to the opposite side of the portion thereof. mounting of the remote vehicle from the top margin of the sloop.