Patent ID: 12188503

DETAILED DESCRIPTION

Some pins may have a shape corresponding to a single cylinder having a circular cross section, such pins being lodged between two mechanical pieces in a cylindrical space, recess, chamber or aperture matching the shape of the pin. While such pins may be effective at contributing to the positioning of the mechanical pieces, or at transmitting forces between the mechanical pieces, it was found that such pins may move or slide away from the cylindrical space in which they are lodged. This may for example be resolved by soldering such pins into place. Such soldering may however be rendered ineffective if for example a significant force is transmitted between the mechanical pieces, whereby such significant force produces breakage of the soldering material, thereby potentially allowing a pin to move out of its position. The present disclosure proposes a pin which may resolve such issues.

This disclosure relates to a pin. In some examples, a pin is a single, integral mechanical piece which has a specific shape. In some examples, a pin is a metal pin. In some examples, a pin is a plastic material or plastic resin pin. The pin according to this disclosure comprises a first cylindrical portion along a pin axis. A cylindrical portion should be understood as a portion which has a shape corresponding to a volume generated by translating a cross section along an axis which is the pin axis. A cross section may for example be a circular, elliptical, oval or polygonal cross section.

The pin according to this disclosure also comprises a second cylindrical portion along the pin axis. The second cylindrical portion has a shape corresponding to a volume generated by translating a cross section along an axis which is the same pin axis as the pin axis generating the first cylindrical portion. A cross section of the second cylindrical portion may for example be a circular, elliptical, oval or polygonal cross section. The cross section of the second cylindrical portion may be the same as or may differ from the cross section of the first cylindrical portion. Using a same cross section for both the first and second cylindrical portions may ease manufacture and permit reversible placement. Using different cross section may permit providing different characteristics for each cylindrical portion, for example to influence the manner in which forces may be transmitted by the pin.

According to this disclosure, the pin according to the present invention comprises two cylindrical portions, the first cylindrical portion axis being offset from the second cylindrical portion axis with the first and the second cylindrical portions sharing a common end plane perpendicular to the pin axis. Such common end plane corresponds to one end of the first cylindrical portion, and to one end of the second cylindrical portion. The first and second cylindrical portions connect at such common end plane perpendicular to the pin axis. The common end plane indeed is defining both a first end cross section at which the first cylindrical portion terminates and a second end cross section at which the second cylindrical portion terminates.

According to this disclosure, the first and second end cross sections partially coincide along a common end cross section area. In other words, the first and second end cross sections do not exactly overlap in the common end plane. This leads to a pin having a discontinuous structure or shape, which will participate in resolving the issue of a pin sliding out of its lodgment as discussed above.

According to this disclosure, the first end cross section further comprises a first offset area extending away from the second end cross section. The first offset area thereby extends away from the common end cross section area. The first offset area thereby is a flat area in the common end plane. Such first offset area may be leaning against a corresponding surface of a mechanical piece with which the pin may cooperate.

According to this disclosure, the second end cross section further comprises a second offset area extending away from the first end cross section. Similarly to the first offset area, the second offset area thereby extends away from the common end cross section area. The second offset area thereby is a flat area in the common end plane. Such second offset area may be leaning against a corresponding surface of a mechanical piece with which the pin may cooperate. The size and shape of an offset area may be chosen in order to influence the manner with which a pin may cooperate with another mechanical piece against which the offset lies.

While the common end cross section area provides structural integrity to the pin by joining the first and the second cylindrical portions, the first and second offset areas provide mechanical structures which permit locking the pin in place in a mechanical system. Such first and second offset areas also may participate in transferring forces from the pin to one or more mechanical pieces against which either one of or both first of the first and second offset areas may lie.

FIG.1illustrates an example of a pin100according to this disclosure. In this example, the pin100comprises a first cylindrical portion101which has a first circular cross section and a first cylindrical portion axis111. The pin100also comprises a second cylindrical portion102which has a second circular cross section and a second cylindrical portion axis112which is parallel to first cylindrical portion axis111and also to an axis of pin100. In thisFIG.1it is clearly shown that axis112is being offset from axis111. This structure leads to creating second offset area122as well as a first offset area which is not visible in this figure, both offset areas having a crescent shape resulting from the shape of the respective cross sections which extend away from a common end cross section area. The common end cross section area together with the first offset area corresponds to the cylindrical cross section of the first cylindrical portion. The common end cross section area together with the second offset area corresponds to the cylindrical cross section of the second cylindrical portion.

FIG.2illustrates another example of a pin according to this disclosure. In this example, the pin200comprises a second cylindrical portion202which has a second circular cross section. The pin200also comprises a first cylindrical portion201whereby the first cylindrical portion201comprises three flat areas231, the first end cross section comprising three segments corresponding to the three flat area, the three flat area being comprised in planes parallel to the pin axis, each one of the three segments being comprised in a respective edge of an equilateral triangle such that this structure leads to creating second offset area222as well as a first offset area which is not visible in this figure where the second offset area222is in the opposite direction of the first offset area along the common end plane, with both offset areas having a shape resulting from the respective cylindrical cross section once removing the end common cross section area. If we consider the cylindrical portion201having a triangular shape, one flat area231ais the border of the second offset area222and one apex area201aforms the first offset area which is not visible in this figure.

One should note that while the illustrated offset areas each form a single offset area, each offset area may comprise several disjoined areas, in function of the shape of the cylinder cross sections of the cylindrical portions. One could for example consider flower like or star like cross sections for either one of or both of the first and second cylindrical portions, such that the offset areas would comprise several areas.

The pin illustrated inFIG.2comprises 3 flat areas231which may for example participate in precisely placing, assembling or orienting the pin or participate in transferring or transmitting a component of a force in a direction perpendicular to each flat area. The pin illustrated inFIG.2thereby permits that each one of the three flat areas transmits a component of a force 120 degrees from each other, due to the equilateral triangle shape on which the cylindrical portion201is based.

In other examples which are not illustrated, the first cylindrical portion comprises a flat area, the first end cross section comprising a segment corresponding to the flat area, the flat area being comprised in a plane parallel to the pin axis, whereby such flat area may participate in locating such a pin and in transferring or transmitting a component of a force in a direction normal or perpendicular to the flat area. The first cylindrical portion may comprise two or more such flat areas. Two flat areas may face each other along a parallel plane to transmit opposite components of forces.

In some examples, each one of the first and the second offset areas covers a surface of less than 30% of the surface of the common end cross section area. This participates in ensuring that the pin maintains a relatively large common end cross section. If the first offset covers 30% of the surface of the common end cross section area and if the second offset covers 30% of the surface of the common end cross section area, the common end cross section area would indeed represent slightly more than thrice the surface of any one of the first or second offset areas. In some examples, each one of the first and the second offset areas covers a surface of less than 40% of the surface of the common end cross section area. In some examples, each one of the first and the second offset areas covers a surface of less than 20% of the surface of the common end cross section area. In some examples, each one of the first and the second offset areas covers a surface of less than 10% of the surface of the common end cross section area. In some examples, each one of the first and the second offset areas covers a surface of less than 5% of the surface of the common end cross section area.

In some examples, the pin has a height along the pin axis, whereby the height is less than the square root of the common end cross section. In some examples, the height is less than two thirds of the square root of the common end cross section. In some examples, the height is less than a third of the square root of the common end cross section. Limiting the height of the pin compared to the size of the common end cross section may permit gaining space in the height direction while maintaining a function of the pin as a shear pin.

In some examples, a pin according to this disclosure is comprised in a system. Such system comprises a first plate parallel to the common end plane and comprising a first aperture matching the first end cross section, whereby the first cylindrical portion of the pin is inserted in the first aperture, and whereby the second offset area lies against the first plate. The first aperture in the first plate may go through the plate or may be a recess in the plate, whereby the first cylindrical portion of the pin would fit into the recess. The fact that the second offset area lies against the first plate participates in precisely placing the pin, whereby the pin fits into the first aperture until the second offset area abuts flush against the first plate.

An example system further comprises a second plate parallel to the common end plane and comprising a second aperture matching the second end cross section, whereby the second cylindrical portion of the pin is inserted in the second aperture, and whereby the first offset area lies against the second plate, the second plate lying against the first plate. The second aperture in the second plate may go through the second plate or may be a recess in the second plate, whereby the second cylindrical portion of the pin would fit into the recess. The fact that the first offset area lies against the second plate participates in precisely placing the pin, whereby the pin fits into the second aperture until the first offset area abuts flush against the first plate.

In some examples, the apertures match the respective cylindrical portions in order to permit a tight fit. In some examples, the apertures match the respective cylindrical portions in order to permit a soldering to reinforce a junction between a plate and the pin. In some examples, the apertures match the respective cylindrical portions in order to permit a loose fit. The aperture may exactly match or approximately match the shape of a corresponding cylindrical cross section. In an example of an approximate match, an aperture matching the cylindrical portion201based on an equilateral triangle may be a circular aperture in which cylindrical portion is tight fitted.

An example system is represented inFIG.3A. Pin300comprises a first cylindrical portion301and a second cylindrical portion302. First cylindrical portion301is located within a first aperture341into a first plate351or “PLATE No 1”. Second cylindrical portion302is located within a second aperture342into a second plate352or “PLATE No 2”.FIG.3Aillustrates how the first offset321lies against the second plate and the second offset322against the first plate.FIG.3Aillustrates how the pin is locked in place between the first and second plates through the disposition of the offset areas against the plates, preventing the pin from sliding out of position, as long as the plates are held against each other. FIG.3A also illustrates how the pin participates in transmitting mechanical energy. In case of an external load360applied in opposite directions on the first and second plates in a direction comprised in the common plane (which is the horizontal plane in the representation ofFIG.3A), the external load will produce a resulting torque370on pin301, such torque producing a shear force, the pin behaving as a shear pin, the pin being submitted to resulting forces371and372, the resulting forces being in a direction perpendicular to the common plane and being applied from the first plate to the second offset area, and from the second plate to the first offset area.

In some examples, the plates are metal plates. In some examples, the plates are elongated along a longitudinal direction parallel to the common plane of the pin. In some examples, the first and second plates are held against each other by fastening elements. In some examples, the plates are elongated along a longitudinal direction parallel to the common plane of the pin and are cylindrical, the cylindrical plates having for example a rectangular cross section along its longitudinal direction. In some examples, the plates have a thickness along the pin axis, whereby the thickness is of less than twice a height of a respective cylindrical portion of the pin along the pin axis. In some examples, the plates have a thickness along the pin axis, whereby the thickness is of less than 1.5 times a height of a respective cylindrical portion of the pin along the pin axis. In some examples, the plates have a thickness along the pin axis, whereby the thickness is of less than 1.2 times a height of a respective cylindrical portion of the pin along the pin axis. Such relationship between the thickness of a plate and the height of a corresponding cylindrical section may permit that a pin may act as a shear pin while limiting the space occupied by the pin.

Another example system is represented inFIG.3B. The system ofFIG.3Bcomprises elements such as a pin300, first plate351and second plate352similar to the elements ofFIG.3Aand represented by the same reference numerals. In this example,311is a central axis of the first cylindrical portion, and312is a central axis of the second cylindrical portion, the central axis311and312being parallel to and shifted from each other to produce the offset areas. The system ofFIG.3Bfurther comprises bolts380and381joining the first351and the second352plates together, whereby the first and second plates comprise matching through apertures for the bolts (not represented here), the bolts passing through the matching through apertures for the bolts. The matching through apertures for the bolts are matching the bolts, and go through each plate so each bolt may be bolted. It should be noted that in case of submitting the system ofFIG.3Bto a shearing action as illustrated inFIG.3A, the bolts and pin will be submitted to shear forces, the forces applying to the pin relieving the force applied to the bolts. It should be noted that such relief on the force submitted to the bolts may prevent a mechanical rupture of such bolts. It should be noted that the pin structure may be very efficient in that the height of the pin along the pin axis parallel to either one of axis311or312may be very reduced, in particular compared to the height of bolts380and381along their bolt axis.

It also should be noted that other possible systems according to this disclosure and comprising such a pin and bolts or other fastening elements or other plate shapes may be considered, including various numbers of pins and fastening elements.

FIG.4illustrates a system491according to this disclosure and another system492according to this disclosure. System491comprises nine bolts481and two pins401between a first plate451and a second plate452according to this disclosure. Other system492comprises other nine bolts482and other two pins402between another first plate453and another second plate454according to this disclosure. Systems491thereby comprises an additional pin according to this disclosure, the first plate451comprising an additional first aperture matching the first end cross section of the additional pin, whereby the first cylindrical portion of the additional pin is inserted in the additional first aperture, and the second plate452comprising an additional second aperture matching the second end cross section of the additional pin, whereby the second cylindrical portion of the additional pin is inserted in the additional second aperture. The other system492has the same structure as the system491in this example.

The system illustrated inFIG.4further comprises a bar499to form a rear underrun protection for a truck, the rear underrun protection comprising systems491and492, the rear underrun protection further comprising a frame, the bar being attached to two or more brackets, each bracket comprising a first plate451and453, the frame comprising the second plates452and454. While this specific example of a rear underrun protection comprises 2 brackets and frames, other configurations may be considered.

In the system illustrated inFIG.4, one or more pins comprise a flat area according to the present disclosure, whereby such one or more pin is inserted so that the flat area is comprised in a plane perpendicular to a longitudinal axis of the truck, the longitudinal axis of the truck being in this example perpendicular to the bar and parallel to the longitudinal axis of second plates or frames452and454. The longitudinal axis of the truck also corresponds to the direction along which the truck is driven.

In the system ofFIG.4, the offset areas of the pins lie against the plates so as to transmit to the plates a shear force originating from a rear underrun shock. The system ofFIG.4comprises a total of four pins, one pair per frame454,452or one pair per bracket451,453, each pin of each pair being mounted in an opposite direction one to the other along a direction perpendicular to the longitudinal direction of the frames454,452behaving in case of shock as illustrated inFIG.3A. InFIG.4, it is clearly shown that pins300have the shape illustrated inFIG.2i.e. with the second cylindrical portion401having a circular shape and the first cylindrical portion402having a triangular shape. If we consider the first cylindrical portions402shown inFIG.4, one can see that they are mounted in opposite direction: both pins of the pair of pins having the flat part432aparallel to the longitudinal axis of the frame454but each pin having the apex area402ain an opposite direction along the direction perpendicular to the longitudinal axis of the frame454.

A rear underrun protection as illustrated inFIG.4may be comprised in a truck and be located at the bottom back end of a truck to avoid or limit the possibility that a vehicle slide under the truck in case of a rear collision. In such a case, a collision would apply a force onto the bar499, the force being transmitted to the brackets451and453corresponding to the first plates451and453, the force being in turn transmitted to the frame or second plates452and454through the bolts and pins, the pins acting as shear pins and reducing a risk or rupture of the bolts, thereby participating in maintaining the integrity of the rear underrun protection.

In the preferred embodiment as shown inFIG.4, the assembly includes two pins300mounted on each frame452,454in opposite direction perpendicularly to the direction of the longitudinal axis. Both pins being aligned on the frame452,454along the longitudinal axis and sufficiently spaced one from the other (e.g. at least 5 cm). The distance between two pins of a pair of pins depends on the size of the pins themselves. With pins of a size of approximately 12 mm in thickness and the cylindrical part being 24 mm in diameter, those should be spaced apart of at least 10 cm and more preferably between 18 cm and 23 cm. Without load on the device, there is no contact between the pin300and the frame452,454(there is a little gap). Therefore, in order to ease the installation and prevent the pins300from falling, each pin300is maintained in place (e.g welded, glued . . . ) on the bracket451,453. During the application of force, the bracket451,453and the frame452,454slide relative to each other as there is no contact between the pin and frame without load. At this moment with the force applied, there is a contact between pins, bracket, and frame.

The special shape of pins300as described above, especially inFIGS.1and2, prevent the pins300from being ejected. The shear force between the bracket451,453and the frame452,454tend to rotate the pin300, but the particular shape of the pins300inserted in the assembly, as shown inFIGS.3A and3B, enable locking the rotation of the pin300and the pin gets self-stuck (even if pins are made with thin sheets, example: 5 mm thickness).

Other embodiments may also be considered where for example each pin would be maintained in place on the frame452,454or where there would be more than one pair of pins with each pair being aligned on the frame452,454along a direction that is parallel to a longitudinal axis of the frame452,454and sufficiently spaced apart (at least 5 cm) along this same axis and each pair of pins having the two pins mounted in opposite orientations one with respect to the other.

In some examples, including the example illustrated inFIG.4, the common end cross section area of the pin is of more than 200 mm2and of less than 1500 mm2. In some examples, the common end cross section area of the pin is of more than 400 mm2and of less than 1200 mm2. In some examples, the common end cross section area of the pin is of more than 600 mm2and of less than 1000 mm2.

FIG.5illustrates an example method500to transmit mechanical energy in a rear underrun protection such as, for example, rear underrun protection illustrated inFIG.4, the method comprising receiving501a rear underrun shock on the bar499, each pin401,402transmitting502mechanical energy produced by the shock to the frame452,454through shear force. Note that such method may apply to underrun protections comprising a shear pin according to this disclosure and different from the specific underrun protection illustrated inFIG.4.

In some examples of method to transmit mechanical energy in a rear underrun protection as per this disclosure, whereby the shear force in each pin is of more than 60 kN at the time of the shock. In some examples, the shear force in each pin is of more than 90 kN at the time of the shock. In some examples, the shear force in each pin is of more than 100 kN at the time of the shock.

In some examples of method to transmit mechanical energy in a rear underrun protection as per this disclosure whereby the rear underrun protection comprises two or more systems that are according to this disclosure and comprising bolts as perFIG.3BorFIG.4, whereby each bolt transmits mechanical energy produced by the shock to the frame through shear force, the shear force in each bolt is of less than the shear force in each pin at the time of the shock, such that the pin reduces the risk that the bolts break. In some examples, a force applied to the bar at the moment of a shock is of less than 180 kN. In some examples, a force applied to the bar at the moment of a shock is of less than 150 kN. In some examples, a force applied to the bar at the moment of a shock is of less than 100 kN. In some examples, a force applied to the bar at the moment of a shock is of more than 80 kN. In some examples, a force applied to the bar at the moment of a shock is of more than 25 kN. In some examples, a force applied to the bar at the moment of a shock is of more than 40 kN. In some examples, a force applied to the bar at the moment of a shock is of more than 50 kN. In some examples, a shear force applied to a bolt at the moment of a shock is of more than 10 kN. In some examples, a shear force applied to a bolt at the moment of a shock is of more than 20 kN. In some examples, a shear force applied to a bolt at the moment of a shock is of more than 30 kN. In some examples, a shear force applied to a bolt at the moment of a shock is of less than 50 kN. In some examples, a shear force applied to a bolt at the moment of a shock is of less than 45 kN. In some examples, a shear force applied to a pin at the moment of a shock is of more than 50 kN. In some examples, a shear force applied to a pin at the moment of a shock is of more than 80 kN. In some examples, a shear force applied to a pin at the moment of a shock is of more than 120 kN. In some examples, a shear force applied to a pin at the moment of a shock is of more than 130 kN. In some examples, a shear force applied to a pin at the moment of a shock is of less than 160 kN. In some examples, a shear force applied to a pin at the moment of a shock is of less than 150 kN. Such numerical thresholds may be combined in function of specific design specifications, including various dimensions, number of pins, bolts or brackets or materials used for a specific rear underrun protection, in order to reduce the risk of mechanical rupture of any of such elements.

In some examples of a method to machine a pin according to this disclosure, the pin is machined by milling an integral piece of metal. Such a method permits maintaining structural integrity while obtaining the offsets. In particular, such a method ensures structural integrity in the area of the common end plane which may be submitted to shear. Such a method may permit a manufacturing precision of the order of a tenth of a millimeter. Such a method may permit a manufacturing precision of the order of a hundredth of a millimeter.