Helmet assemblies with flip-type welding visors

Improvements to helmet assemblies with flip-type welding visors are provided. In one embodiment, a return mechanism applies a predetermined force to a wireform spring. The return mechanism applies a force between a welding visor and a grinding shell, while concurrently reducing rotational forces needed to flip up the welding visor from the grinding shell. In another embodiment, a combination of an adjustable spring and a slide stop provides an adjustable stopping position for the wireform spring. The adjustable stopping position permits adjustable balancing of the forces that are applied to the wireform spring.

TECHNICAL FIELD

The present disclosure generally relates to welding helmets and, more specifically, to improvements to helmet assemblies with flip-type welding visors.

DESCRIPTION OF THE RELATED ART

Multi-purpose industrial helmets are known that provide numerous functional and safety features to a wearer. One such helmet is a flip-type helmet that incorporates head gear for mounting the helmet to the wearer and a movable welding visor. Due to various impediments to a user's ability to easily “flip” the visor, there are ongoing to improve such flip-type helmets.

SUMMARY

Improvements to helmet assemblies with flip-type welding visors are provided. In one embodiment, a return mechanism applies a predetermined force to a wireform spring. The return mechanism applies a force between a welding visor and a grinding shell, while concurrently reducing rotational forces needed to flip up the welding visor from the grinding shell. In another embodiment, a combination of an adjustable spring and a slide stop provides an adjustable stopping position for the wireform spring. The adjustable stopping position permits adjustable balancing of the forces that are applied to the wireform spring.

DETAILED DESCRIPTION

In this regard,FIG. 1is a schematic, exploded view of an example embodiment of a helmet assembly. As shown inFIG. 1, helmet assembly100includes a grinding shell102and a welding visor104. The grinding shell102is configured to receive the head of a wearer, with mounting of the assembly to the wearer's head typically being accomplished by head gear (e.g., straps and/or bands) that is not shown in these figures. The grinding shell102has a front106for positioning near the face of a wearer, a left side110for positioning near the left cheek of the wearer, a right side112for positioning near the right cheek of the wearer, and a back114. An opening116is located at the back114and is configured to receive the head of the wearer of the helmet assembly.

A grinding view port120is located at the front106that mounts a grinding cover plate122through which a wearer's line of sight is directed during a grinding operation, for example. Grinding view port120is defined, at least in part, by a chin portion124that spans between the left and right sides110,112along a lower edge126, and by a cranium portion128that spans between the left and right sides110,112along an upper edge130.

Welding visor104is mounted to grinding shell102and is rotatable about a rotational axis132. In the embodiment depicted inFIG. 1, mounting of welding visor104to grinding shell102is facilitated by corresponding pairs of mounting apertures134,135of welding visor104that align with apertures136,137of grinding shell102. Knob assemblies140,142include shafts144,145that extend through the apertures for retaining alignment of the apertures. In some embodiments, knob assemblies140,142may enhance retention of welding visor104at selected positions about axis132by providing user-adjustable frictional engagement between welding visor104and grinding shell102such as by via an interposed rubber bushing (not shown).

Welding visor104incorporates a welding view port146that mounts a welding cover plate148through which a wearer's line of sight extends during a welding operation, for example. As will be described in greater detail, welding visor104is rotatable about rotational axis132between a lower position (depicted inFIG. 2A) and an upper position (depicted inFIG. 4A). In the lower position, welding visor104is seated against grinding shell102to prevent unwanted light leakage between the components. Additionally, welding view port146is aligned with grinding view port120so that a line of sight of the wearer of helmet assembly100extends through the grinding view port and then the welding view port. In the upper position, welding visor104is rotated toward the back148of the grinding shell so that the line of sight of the wearer is unobstructed by the welding visor. For instance, in this embodiment, the welding view port146is positioned above the cranium portion128. It should be noted that the “line of sight” is a sight line extending through the grinding cover plate122.

Also depicted inFIG. 1is a connector150that extends between grinding shell102and welding visor104. In this embodiment, connector150is a wireform that is rotatable about axis152, which is parallel to but displaced from axis132. Functionality of the connector will be described in detail later.

In operation, interaction of grinding shell102and welding visor104provides a biasing force to urge the welding visor towards a selected position (e.g., the lower position or the upper position). For instance, as the welding visor approaches the lower position, a biasing force is present that urges the welding visor downwardly against the grinding shell. The extent of the biasing force is derived from numerous factors, such as (but not limited to): contact surface shapes of the exterior of grinding shell102and the interior of welding visor104; size and/or shape of the connector150; location of the rotational axes (132,152); attachment locations of the connector; and resilience of the materials forming grinding shell102, welding visor104and connector150. Preferably, the biasing force exhibited at the lower and upper positions is greater (e.g., minimally greater) than the weight of the welding visor (and any components installed thereon) in order to retain the desired position regardless of the orientation of the helmet assembly.

FIGS. 2A and 2Bdepict helmet assembly100with welding visor102in the lower position160. As may be see more clearly inFIG. 2B, the lower position160is exhibited by lower edge172of welding visor104abutting ledge174of grinding shell102after the welding visor is rotated downwardly towards the grinding shell about axis132. Welding visor104is retained in this position by a biasing force. In the lower position, line of sight176of a wearer of the helmet assembly extends through grinding view port120and welding view port146. Preferably, welding view port146is aligned (to the extent possible) with grinding view port120.

Connector150, which extends between the exterior of grinding shell102and the interior of welding visor104, includes a shell end182and a visor end184. Shell end182is rotatably connected to grinding shell102so that the connector may rotate about axis152. Visor end184of the connector engages welding visor104and assists in guiding the welding visor between the various positions relative to the grinding shell and/or to enhance the extent of biasing force applied to the welding visor. In this embodiment, engagement of connector150with welding visor104is facilitated by a pair of cam slots, only one of which (i.e., cam slot190) is depicted inFIG. 2B. Specifically, visor end184of the connector engages and is guided by cam slot190.

FIGS. 3A and 3Bdepict the helmet assembly100with welding visor104in an intermediate position200. As shown inFIG. 3B, the intermediate position200is exhibited by lower edge172of welding visor104at least partially obstructing the line of sight176. Notably, welding visor104has been rotated upwardly and rearwardly toward the back114of the grinding shell about axis132.

At intermediate position200, the biasing force exerted upon welding visor104reaches a maximum as potential energy is loaded into various components of the helmet assembly. In this embodiment, deflection in the material of cranium portion128and connector150are evident (shown by arrows DC for the cranium portion and DW for the connector). Note that connector150is depicted for clarity at its non-deformed length (which does not actually occur in this embodiment), with arrows DW representing the difference in radial path of connector visor end184and the welding visor104, which is later described more fully with respect toFIG. 9.

FIGS. 4A and 4Bdepict helmet assembly100with welding visor104in the upper position220. As shown inFIG. 4B, the intermediate position220is exhibited by the line of sight176of the wearer being unobstructed by the welding visor104. Notably, welding visor104has been rotated upwardly and rearwardly from the intermediate position toward the back114of the grinding shell about axis132.

FIGS. 5 and 6depict a welding visor250being rotated from its lower position252, through an intermediate position254, to an upper position256. InFIG. 5, the intermediate position254and upper position256of the welding visor are presented in phantom lines. Relative orientations of a representative cam slot260, which is carried by an interior surface of the welding visor, are depicted with each location of the cam slot inFIG. 6corresponding to a position of the welding visor shown inFIG. 5.

As shown inFIG. 5, repositioning of welding visor250from the lower position252to upper position256involves rotating the welding visor about axis264so that the welding visor moves through arc266. As shown inFIG. 6, repositioning of welding visor250also involves the reorientation of cam slot260and interaction of the cam slot with connector270.

In particular, at lower position252, a biasing force (represented by vector FL) is present for retaining the welding visor in the lower position. In this position, connector270extends from point of rotation (P1) to an intermediate portion271of cam slot260. As welding visor250is rotated along arc266toward intermediate position254, distal end272of connector270is guided outwardly along the cam slot until seating at the radially outward end274of the cam slot.

Further movement of the welding visor along the arc with the connector seated at end274of the cam slot causes loading of the helmet assembly with potential energy resulting in deflection of the connector, welding visor and/or grinding shell. Note that during this movement, the biasing force has changed in direction and magnitude (represented by vector FI). In this embodiment, the various deformations cause the repositioning of the point of rotation from P1to P2(the deflection of the point of rotation is expressed as DP).

From intermediate position254, continued movement of the welding visor along the arc266results in an unloading at least some of the potential energy as the point of rotation repositions to P1. Further movement of the welding visor causes the distal end272of the connector to be guided to the radially inward end276of the cam slot. During this movement from position254to position256, the biasing force has changed again in direction and magnitude (represented by vector FU).

FIG. 7depicts an example embodiment of a connector300configured as a wireform. As shown inFIG. 7, connector300is generally U-shaped incorporating a base302with arms304,306extending outwardly therefrom. In this embodiment, base302includes an optional offset segment310located approximately midway between the ends312,314of the base. The offset may be used to restrict side-to-side movement of the connector when implemented in conjunction with a corresponding stop positioned between the legs of the offset segment.

In the embodiment ofFIG. 7, each of the arms304,306exhibits an included angle of between approximately 150-170 degrees. Distal ends316,318of the arms terminate in outwardly extending cams320,322that are configured to engage within corresponding cam slots.

FIG. 8depicts a helmet assembly350that includes a grinding shell352, a welding visor354and connector300ofFIG. 7. As shown inFIG. 8, the welding visor354is retained in the upper position356by an embodiment of a locking mechanism360. Locking mechanism360assists in retaining welding visor354in the upper position by forming an interference fit with the arms304,306of the connector. In particular, locking mechanism360is attached to cranium portion362of grinding shell352and serves as a mount for the base302of the connector. So attached, the connector is able to rotate about an axis364defined by the locking mechanism.

In one embodiment, locking lugs366,368extend outwardly from locking mechanism360. The locking lugs are positioned to capture arms304,306of the connector by interference fit as the connector is carried by the welding visor during movement towards the upper position. As the arms encounter the locking lugs during this movement, continued application of force by the arms against the locking lugs deflects the arms outwardly from each other until the arms clear the locking lugs. Thus, the locking lugs form a mechanical lock of the welding visor when in the upper position that supplements the biasing force in retaining the position of the welding visor.

In another embodiment, the locking mechanism excludes locking lugs. In such an embodiment, locking of the welding visor in the upper position may be facilitated by the angles and shaped surfaces of the radially inward end276of the cam slot.

In order to disengage the mechanical lock, the welding visor354is urged toward the intermediate position with sufficient force to cause the arms to deflect away from each other for clearing the locking lugs of the locking mechanism.

FIG. 9is a cross-sectional view of another embodiment of a helmet assembly400, which includes a grinding shell402and a welding visor404. Welding visor404is mounted to grinding shell402and is rotatable about a rotational axis406. A connector408extends between grinding shell402and welding visor404, with the connector being rotatable about axis410. As in previous embodiments, distal ends of the connector (e.g., distal end412is shown inFIG. 9) ride in corresponding cam slots (e.g., slot414).

As shown inFIG. 9, rotation of welding visor404about axis406results in the head416of cam slot414rotating along an arc420(depicted in dashed lines). Additionally, arc422(also depicted in dashed lines) represents the path along which the distal end412of connector408rotates when not being deflected during carriage by the welding visor—deflection typically occurs when connector408is attached to welding visor404resulting in biasing forces. Note that shaded region424, which corresponds to the overlap of arcs420and422, represents the locations and corresponding magnitude of biasing forces present within the helmet assembly during operation. These biasing forces are present because the distal ends of connector408are prevented from extending outwardly beyond the heads of the cam slot (which corresponds to arc420) in which it rides, resulting in deflection of the connector and possibly one or more other components of the helmet assembly. These biasing forces urge the welding visor towards the selected position.

As shown in the embodiments ofFIGS. 1 through 9, the connector300(FIG. 7), which is shown as a wireform spring300, travels in a cam slot260when a user moves the welding visor104(FIG. 1) up or down with reference to the grinding shell102(FIG. 1) through a rotational motion. Multiple factors affect the force that is needed to flip the welding visor104, these factors include flexibility (or the stiffness) of the wireform spring300, the location of the wireform spring300in the cam slot260when the welding visor104is in the down position, the shape of the grinding shell102, any modification to the upper part of the grinding shell, and/or the use of additional components within the grinding shell102that affect the stiffness of the grinding shell, including, though not limited to, a head harness (headgear). Thus, if any of the factors change they can significantly impact the amount of force necessary to rotate the welding visor104on the grinding shell102. For example, if the wireform spring300is too stiff, then it becomes more difficult to flip the welding visor104. Conversely, if the wireform spring300is not stiff enough, then the welding visor104may flip (up or down) at inconvenient moments (either due to gravity or due to movement by the user).

Another example is the harness used to hold the complete helmet to the users head. Adjusting this harness affects the shape of the grinding shell and thus its contributing factor to the force applied to resisting the rotation motion of welding visor104on grinding shell102. These are but two examples of the multiple factors influencing the force applied to resisting the rotation motion of welding visor104on grinding shell102.

FIGS. 10A, 10B, 10C, 11A, 11B, and 11Cshow embodiments that permit adjustment of a resting/stop location of the wireform spring300when the welding visor104is in the down position, thereby ameliorating issues that arise from the multiplicity of variable factors affecting the applied force on the complete spring mechanism. Specifically,FIGS. 10A, 10B, and 10C(collectively designated asFIG. 10) show an example embodiment of a return mechanism that applies a predetermined force to a wireform spring, andFIGS. 11A, 11B, and 11C(collectively designated asFIG. 11) show an example embodiment of an adjustment knob that permits an adjustable stop location of the wireform spring. Attention is now turned to these embodiments.

FIG. 10shows one embodiment of a welding visor104a, which is similar to the welding visor104ofFIG. 1. Specifically,FIG. 10Ashows a perspective view of the embodiment, whileFIG. 10Bshows a profile view as the welding visor104ais moved from a lower position to a middle position, andFIG. 10Cshows the same profile view asFIG. 10Bbut as wireform spring returns to its initial position.

Recalling, the welding visor104ofFIG. 1comprises a pair of cam slots190in which a wireform spring300travels, thereby permitting controlled movement of the welding visor104(FIG. 1) with reference to the grinding shell102(FIG. 1). In addition to the components of the welding helmet assembly100shown inFIG. 1, the welding visor104aofFIG. 10comprises a pair of return spring bosses1030a,1030b(collectively,1030) located near the cam slots190. Additionally, the embodiment ofFIG. 10comprises a return mechanism1000with a pair of cylinders1010a,1010b(collectively,1010) on each side of the return mechanism1000, and a pair of return compression springs1020a,1020b(collectively,1020). One end of each return compression spring1020engages its respective return spring boss1030. The other end of each return compression spring1020nests within its respective cylinder1010on the return mechanism1000.

When mounted, the return mechanism1000slides along return slide rails1008a,1008b(collectively1008) with lobes1002a,1002b(collectively1002) of the return mechanism1000engaging one end of the wireform spring300. In other words as shown inFIG. 10B, the return mechanism1000applies a force to the wireform spring300from the return compression springs1020, thereby positioning the wireform spring300to an optimal, fixed position. The fixed position is based on a size of a stop bar1004and a fixed position of a stop rib1006on welding visor104a, which apply the desired force necessary to the complete wireform spring-assisted movement. Without the return mechanism1000, the wireform spring300can move, depending on the multiple factors listed above into a non-optimal position. The applied force results in a repositioning of the wireform spring300, thereby effectively changing the amount of additional force needed to flip the welding visor104a. Furthermore, because the return mechanism1000returns the wireform spring300to a predetermined location (and consequently resulting in a pre-compression of the wireform spring300) when the welding visor104ais flipped down, the return mechanism1000provides a balance between forces, namely, between the force needed to flip up the welding visor104aand the force needed to prevent the welding visor104afrom inadvertently flipping up.

Although the embodiment ofFIG. 10provides a fixed pre-compression of the wireform spring300, it is also possible to provide a variable compression to the wireform spring300by a mechanism such as that shown inFIG. 11. Specifically,FIG. 11Ashows a perspective view of this embodiment, whileFIGS. 11B and 11Cshow profile views where more force (FIG. 11B) and less force (FIG. 11C) are applied to the return mechanism1000by the use of an adjustment knob1075.

The embodiment ofFIG. 11comprises the return mechanism1000(shown mounted to the welding visor104bthrough cylinders1010). Additionally, the embodiment ofFIG. 11comprises a slide stop1040, an adjustable spring1050, a spring boss1045, a slide stop cover1060, a screw1085, a visor screw hole1095, and a slide stop adjustment knob1075with a threaded bolt1090.

Structurally, the slide stop1040comprises a threaded hole1055, which has dimensions that can accommodate the threaded bolt1090of the adjustment knob1075. The slide stop cover1060comprises a cover screw hole1065(for the screw1085) and a bore1070(for the threaded bolt1090). The adjustable spring1050resides between the spring boss1045and the slide stop1040, with one end of the adjustable spring1050engaging the spring boss1045and the other end of the adjustable spring1050engaging the slide stop1040. The slide stop cover1060holds the slide stop1040against the adjustable spring1050, which in turn is held to the welding visor104bby the spring boss1045. The slide stop cover1060is secured to the welding visor104bby the screw1085, which threads both the cover screw hole1065and the visor screw hole1095. The threaded bolt1090inserts into the bore1075and rotationally mates with the threaded hole1055.

Thus, if a user turns the adjustment knob1075in one direction, then the slide stop1040compresses the adjustable spring1050. Similarly, if the user turns the adjustment knob1075in the other direction, then the slide stop1040decompresses the adjustable spring1050. The ability to selectively compress and decompress the adjustable spring1050results in controlled variability of the location of the return mechanism1000. This ability to control the location of the return mechanism1000results in a corresponding ability to control the forces that are needed to flip the welding visor104bas shown inFIGS. 11B and 11C.

Structurally, the embodiment ofFIG. 10comprises a grinding shell102(FIG. 1) and a welding visor104arotatably coupled to the grinding shell102(FIG. 1). The welding visor104ahas an inside and an outside. The embodiment ofFIG. 10Afurther comprises a cam slot190located on the inside of the welding visor104a, and a spring boss1030that is also located on the inside of the welding visor104a. The spring boss1030is located beside the cam slot190. The embodiment ofFIG. 10further comprises a compression spring1020having a first end and a second end, with the first end of the compression spring being mechanically coupled to the spring boss1030. The embodiment ofFIG. 10further comprises a wireform spring300having a sliding end and a rotating end, with the sliding end of the wireform spring300being slidably engaged to the cam slot190, and the rotating end of the wireform spring300being rotatably engaged to the grinding shell102(seeFIG. 1). The embodiment ofFIG. 10further comprises a return mechanism1000, which is mechanically coupled to the second end of the compression spring1020. The return mechanism1000applies a compression force to the compression spring1020. The return mechanism1000further defines a starting position from which the sliding end of the wireform spring300slidably engages the cam slot190.

It should be appreciated that the pre-tensioning of the return mechanism (as shown inFIG. 10) and the adjustable mechanism (as shown inFIG. 11) are not trivial or routine improvements of the helmet assembly100ofFIGS. 1 through 9. This is because problems relating to the stiffness of the wireform spring300are not readily apparent fromFIGS. 1 through 9. Furthermore, because the pre-tensioning provided by the return mechanism1000must avoid interfering with the movement of the wireform spring300as the wireform spring300travels along the cam slots190, designing and implementing the return mechanism1000requires consideration of multiple factors. Furthermore, because the adjustment mechanism (shown inFIG. 11) must not hinder or obstruct the movement of the wireform spring300along the cam slots190, the adjustment mechanism (FIG. 11) requires consideration of even more factors. Stated differently, those having ordinary skill in the art will understand that the problem of a wireform spring300being too stiff (or not stiff enough) is not one that can be readily appreciated by mere reference toFIGS. 1 through 9, and that the particular solutions to this problem, as described inFIGS. 10 and 11, require particular considerations of the behavior of the wireform spring300, with those considerations being neither trivial nor insignificant.