Apparatus for accepting a self-drilling screw   

This application claims the benefit of U.S. Provisional Application No. 61/060,501, filed on Jun. 11, 2008, which is incorporated herein by reference in its entirety.

This application is related to the following co-pending United States patent applications, all of which were filed on Jun. 11, 2008, and are hereby incorporated herein by reference:

U.S. patent application Ser. No. 12/137,322 (attorney docket number 100.1027US01 entitled “COMMUNICATION MODULES”) and which is referred to here as the \'1027 Application;

U.S. patent application Ser. No. 12/137,297 (attorney docket number 100.1028US01 entitled “APPARATUS FOR MOUNTING A MODULE AND ENABLING HEAT CONDUCTION FROM THE MODULE TO THE MOUNTING SURFACE”) and which is referred to here as the \'1028 Application;

U.S. patent application Ser. No. 61/060,589 (attorney docket number 100.1029USPR entitled “SUSPENSION METHOD FOR COMPLIANT THERMAL CONTACT OF ELECTRONICS MODULES”) and which is referred to here as the \'1029 Application;

U.S. patent application Ser. No. 12/137,307 (attorney docket number 100.1033US01 entitled “ANGLED DOORS WITH CONTINUOUS SEAL”) and which is referred to here as the \'1030 Application;

U.S. patent application Ser. No. 61/060,523 (attorney docket number 100.1031USPR entitled “L-SHAPED DOOR WITH 3-SURFACE SEAL FOR ENDPLATES”) and which is referred to here as the \'1031 Application;

U.S. patent application Ser. No. 61/060,576 (attorney docket number 100.1032USPR entitled “L-SHAPED DOORS WITH TRAPEZOIDAL SEAL”) and which is referred to here as the \'1032 Application;

U.S. patent application Ser. No. 12/137,309 (attorney docket number 100.1033US01 entitled “SYSTEMS AND METHODS FOR VENTURI FAN-ASSISTED COOLING”) and which is referred to here as the \'1033 Application;

U.S. patent application Ser. No. 61/060,547 (attorney docket number 100.1034USPR entitled “COMBINATION EXTRUDED AND CAST METAL OUTDOOR ELECTRONICS ENCLOSURE”) and which is referred to here as the \'1034 Application;

U.S. patent application Ser. No. 61/060,584 (attorney docket number 100.1035USPR, entitled “SYSTEMS AND METHODS FOR CABLE MANAGEMENT” and which is referred to here as the \'1035 Application;

U.S. patent application Ser. No. 61/060,581 (attorney docket number 100.1037USPR entitled “CAM SHAPED HINGES”) and which is referred to here as the \'1037 Application;

U.S. patent application Ser. No. 12/137,313 (attorney docket number 100.1038US01 entitled “SOLAR SHIELDS”) and which is referred to here as the \'1038 Application;

U.S. patent application Ser. No. 61/060,593 (attorney docket number 100.1040USPR entitled “SYSTEMS AND METHODS FOR THERMAL MANAGEMENT”) and which is referred to here as the \'1040 Application;

U.S. patent application Ser. No. 61/060,762 (attorney docket number 100.1062USPR entitled “SERF BOARD COMPONENTS”) and which is referred to here as the \'1062 Application; and

U.S. patent application Ser. No. 61/060,740 (attorney docket number 100.1064US01 entitled “PULL-OUT SHELF FOR USE IN A CONFINED SPACE FORMED IN A STRUCTURE”) and which is referred to here as the \'1064 Application.

One typical use of self-drilling screws is to insert the screws into a flat surface that is composed of a material that can accept the screw. One example of such a material is wood. For this use, the screw should be substantially harder than the material in which the screw is inserted because the screw must “drill” its own hole in the material during insertion of the screw.

Another typical use of a self-drilling screw is to insert the screw into a pre-fabricated circular hole. Here the pre-fabricated hole is sized such that the main body of the screw can be inserted through the hole, while the threads of the screw engage (cut or form) into the sides of the hole. When a pre-fabricate hole is used, the location of the hole is determined prior to insertion of the screw and the hole is formed. This may require machining at the factory which adds cost to the fabrication and reduces flexibility in the location of the screw. Otherwise, an installer may need to drill a hole prior to insertion of the screw which requires added time and tools for the screw installation.

SUMMARY

The following summary is made by way of example and not by way of limitation. In one embodiment, an apparatus for accepting a self-drilling screw is provided. The apparatus comprises a base structure having at least one channel. The at least one channel has a first side, a second side, and a bottom, forming a generally ‘u’ shaped cross section, wherein t the first side and the second side are a distance apart such that threads of a self-drilling screw engage with both the first side and the second side when the screw is inserted into the channel.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more easily understood, and further advantages and uses thereof are more readily apparent, when considered in view of the detailed description and the following figures in which:

FIG. 1 is a perspective view of one embodiment of a structure having channels for insertion of self-drilling screws;

FIG. 2A is an end view of the structure of FIG. 1;

FIG. 2B is an enlarged end view of the structure of FIGS. 1 and 2A;

FIG. 3 is a perspective view of one embodiment of a screw for inserted into the channels of FIG. 1;

FIG. 4A is an end view of the structure of FIG. 1 having a cover and a latch attached thereto;

FIG. 4B is an enlarged end view of a portion of FIG. 4A;

FIG. 4C is an enlarged end view of a portion of FIG. 4A;

FIG. 4D is an enlarged end view of a portion of FIG. 4A; and

FIG. 5 is an end view of an alternative embodiment of a structure having a channel for insertion of self-drilling screws.

In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize specific features relevant to the present invention. Like reference characters denote like elements throughout the Figures and text.

In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific illustrative embodiments in which the method and system may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit and scope of the present invention. The following description is, therefore, not to be taken in a limiting sense.

FIG. 1 illustrates one embodiment of a structure 100 having a plurality of channels 102 for accepting self-drilling screws. Use of a self-drilling screw is sometimes referred to as blind insertion of a screw. In this embodiment, structure 100 is a door for an enclosure (not shown). Furthermore, in this embodiment, structure 100 acts as a heat sink for components within the enclosure. More detail regarding the use of structure 100 as a door and for an enclosure is provided in co-pending U.S. patent application Ser. No. 12/137,307, entitled “ANGLED DOORS WITH CONTINUOUS SEAL” (\'1030 Application), which is hereby incorporated herein by reference.

In one embodiment, structure 100 is composed of a malleable material. For example, in one embodiment, structure 100 is Aluminum. In one embodiment, structure 100 is composed of a T6 temper Aluminum. T6 temper Aluminum is a hard Aluminum with an especially hard skin. In other embodiments, structure 100 is composed of steel, plastic, a composite, or other suitable material as known to those skilled in the art.

As shown in FIG. 1, channels 102 extend along a length 106 of structure 100 and are substantially parallel to one another. Advantageously, using channels as a blind material for inserting self-drilling screws enables the channels and a corresponding structure to be formed inexpensively. In particular using channels as a blind material enables formation of structure by extrusion, while still allowing a screw to be inserted into the structure in a blind manner along the length of the extrusion. This provides many benefits. For example, construction costs are decreased because of reduced machining on the structure. In other embodiments, however, channels 102 may be in other orientations and structure 100 may be formed through other processes.

FIGS. 2A and 2B show end views of structure 100 providing additional illustration of the structure of each channel 102. FIG. 2A is an end view of structure 100, and FIG. 2B is an enlarged end view of a portion of structure 100 from FIG. 2A showing three channels 102.

As shown in FIG. 2B, each channel 102 has first and second sides 202 and a bottom 204 forming a generally ‘u’ shaped cross-section. Each channel 102 also has a width 206. Width 206 is the distance between first and second sides 202. Width 206 is related to the size of screw drilled into channel 102, and affects the strength of the resulting connection between the screw and channel 102. Generally, the smaller width 206 is the stronger the connection between the screw and the channel. Likewise, a larger width 206 (assuming the same size screw) generally results in weaker connections, but requires less torque to insert the screw. The strength of the connection and torque required occur because of the thread engagement of the screw in channel 102. More detail regarding thread engagement, screw size, and width 206 of channel 102 is provided below.

FIGS. 3A and 3B show perspective views of one embodiment of a self-drilling screw 300 for use with structure 100 and channels 102. Screw 300 comprises at least one thread 302 and a head 304. In one embodiment, screw 300 is a sheet metal screw. Screw 300 is a self-drilling screw meaning that an intended use for screw 300 is in substrates that do not have threads for screw 300. Thus, as screw 300 is twisted into channel 102, screw 300 forms its own threads in each side 202 of channel 102.

Channel 102 may be designed such that width 206 is smaller or larger than that shown in FIGS. 1, 2A, and 2B based on the desired strength of the connection between screw 300 and the twisting resistance while twisting screw 300 into channel 102. Furthermore, screws other than screw 300 may be used.

The connection strength and twisting force and in turn width 206 of channel 102 are determined based on a percentage of engagement of threads 302 of screw 300 and a length of engagement of threads 302 of screw 300. The percentage of threads 302 of screw 300 that are engaged in sides 202 of channel 102 is referred to herein as the “percentage of engagement” of screw 300. The percentage of engagement refers to the lateral distance (in the direction of arrow 208 into each respective side 202 of channel 102) that threads 302 of screw 300 penetrate into sides 202 of channel 102. Thus, the percentage of engagement of screw 300 is related to the diameter of threads 302 of screw 300 and width 202 of channel 102. A length of thread engagement refers to the amount of the thread along the length of screw 300 that is engaged in channel 102. This is determined by a depth 210 of the channel 102, and the spacing of threads 302 from one another. Thus, the length of threads 302 is measured in a spiral manner from the tip of screw 300 to head 304 according to the amount of screw inserted into channel 102. The spacing of threads 306 is the distance between arrows 308.

The higher the penetration of threads 302 into sides 202 (and thus the higher the percentage of engagement of screw 300), the higher the torque required to turn screw 300 into channels 102. A higher thread engagement also results in a stronger connection between screw 300 and channel 102. Likewise, a lower percentage of engagement results in a lower torque required to turn screw 300 into channel 102, and a weaker connection between screw 300 and channel 102.

Typically, blind insertion of a screw occurs with a hole in the material that the screw is being inserted into. Thus, standard tables exist which provide desired relationships between the diameter of a hole that should be provided for a particular screw and a particular thickness and type of material. In one embodiment, the information in these tables is used to determine the width of channels 102. For example, based on a desired parameters a screw and hole size are determined from the table discussed above, and the hole size is used to determine width 206 for channels 102.

For example, first the desired diameter hole is determined based on the thickness and hardness of the material, and the type of screw. Then the diameter is used to determine width 206 of channels 102. Since when screw 300 is inserted into channels 102, screw 300 is engaged in two walls (sides 208 of channel 102) instead of engagement on all sides of screw 300 as in a circular hole implementation, width 206 of channel 102 is set closer together than the determined diameter of the hole. Threads 202 are therefore engaging into sides 308 farther than would occur in an implementation with a hole. This attempts to make the percentage of thread engagement in the channel implementation equal to that of the circular hole implementation. In other embodiments, other methods are used to determine the width 206 of channel 102.

Width 206 of channel 102 affects the friction and torque on screw 300 while screw 300 is being inserted in channel 102. Thus, width 206 (and selection of screw 300) is determined based on friction and torque that can be applied to screw 300. If the torque on screw 300 is too great, head 304 of screw 300 may rupture and break off of screw 300 during insertion or removal of screw 300. This may be undesirable in certain situations.

In one embodiment, chamfers 212 are provided at the top of channels 102 to reduce thread engagement when starting screw 300 in channel 102. Chamfers 212 reduce the torque required to start screw 300 into channel 102 and assist in locating the channel if the mating part is large enough to cover a large portion of the channel. As shown in FIG. 2B, chamfers 212 are located at the opening of channel on a boundary between each of sides 202 and the top portion of structure 100 adjacent to sides 202. Although as illustrated in FIGS. 2A and 2B, chamfers 212 are approximately 45 degrees in angle with respect to sides 202, in other embodiments, chamfers 212 are at other angles with respect to sides 202. Designing channels 102 with a different angled chamfer 212 alters the torque and thread engagement gradient as screw 300 is inserted into channel 102. For example, in one embodiment, sides 202 of channels 102 are tapered, such that as screw 300 is inserted farther into channel 102, thread engagement increases and torque required also increases.

In the embodiment shown in FIGS. 1, 2A, and 2B, channels 102 extend outward from the surface of structure 100. Channel 104 is an elevated channel which is explained in more detail with reference to FIG. 4D. Also, as shown in FIGS. 1, 2A, and 2B channels 102 are parallel to one another, and two adjacent channels 102 share a common wall.

FIGS. 4A-4D illustrate one embodiment of screws 300 inserted into channels 102. In FIGS. 4A-4D screws 300 attach a cover 402 to structure 100. FIG. 4A illustrates an overall end view of structure 100 having cover 402 and a latch 404 attached thereto, while FIGS. 4B-4D are enlarged portions of areas of FIG. 4A. Cover 402 and latch 404 are described in more detail in the \'679 App.

FIG. 4B is an enlarged end view of structure 100 showing cover 402 attached to structure 100 with a screw 200 in an elevated channel 104. As shown in FIG. 4B threads 302 of screw 300 are engaged with sides 202 of channel 102 when screw 300 is inserted into channel 102.

FIG. 4C is an enlarged view of structure 100 showing a latch 404 attached to structure 100 with two screws 200 in channels 102. Latch 404 is secured with two screws 300 into structure 100. Advantageously, latch 404 and cover 402 may be connected to structure 100 in different locations to adjust the location of latch 404 and cover 402. For example, using channels 102 with self-drilling screw 300 enables the location that screw 300 is inserted into structure 102 to be flexible. In other words, screw 300 may be inserted in anywhere along the length of a channel 102. The location of insertion of screw 300 is not restricted to a single (or one of a plurality of) predetermined locations as is the case with predrilled blind holes. This enables screw 300 to be placed in a non-predetermined location resulting in flexibility of use of corresponding structure. For example, this enables the location of latch 404 and cover 402 to be flexible. The flexibility of location may also result in better fitting of the parts which are attached to structure, because screws 300 may be placed precisely where needed for the exact part used.

FIG. 4D is an enlarged end view of structure 100 showing screw 300 screwed into an elevated channel 104 while securing cover 402 to structure 100. Elevated channel 104 comprises an upright portion 406 which extends a channel portion 408 out from the main body of structure 100. Although in this embodiment a single straight portion is used, in other embodiments, other styles of upright portions may be used.

FIG. 5 illustrates another embodiment of a channel 502 for use with a self-drilling screw 300. Channel 502 is a groove into structure 500. Thus, the opening of channel 502 is generally aligned with the surface of the surrounding structure, and the bottom of channel 502 is inset into the structure. As shown, lead-in chamfers 504 are also provided similar to that described with referent to FIG. 2B.

Additionally, as mentioned above, the use of channels 102 also enables the placement of the screw into channel 102 without requiring a pre-drill a hole of a desired size. This may minimize tools required when blind screwing a screw, which is particularly advantageous if parts are put together in the field. Also, the combination of forming the structure from extrusion and the flexible location of placing the screw enables the length of the structure to be adjusted to fit a particular application. For example, a relatively short structure may be formed, or a relatively long structure may be formed, and parts conforming to one or the other may simply be attached with a blind screw anywhere along a channel.