SAFETY DEVICES FOR SCISSOR LIFTS AND RELATED METHODS

Safety devices for scissor lifts comprise a block, a bracing structure, and an actuator. The block is configured to be fixed relative to a base of the scissor lift. The actuator is configured to selectively translate the bracing structure between a braced position, in which the bracing structure is operatively positioned between the block and a support leg of the scissor lift, and a retracted position, in which the bracing structure is not positioned between the block and the support leg of the scissor lift.

FIELD

The present disclosure relates to safety devices for scissor lifts and to related methods.

BACKGROUND

Scissor lifts are work platforms used to safely move workers or components vertically and/or to different locations in a variety of industries including construction, manufacturing, retail, and entertainment. The lifting mechanism of a scissor lift moves the platform straight up and down using cross beams functioning in a scissor-like fashion. To keep a scissor lift in good usable condition, regular maintenance on a plurality of components of the scissor lift arranged under the platform is required. Due to the placement of these components, the scissor lift is often required to be in a vertically extended state during maintenance to allow a mechanic or other personnel access to the components under the platform; however, having maintenance performed under an extended scissor lift is a safety concern.

In some examples, such as in the manufacturing of an airplane wing, multiple scissor lifts may be arranged in close proximity to one another and/or between vertical supply racks, such that the only ways to access the components under the lift are to either crawl under the vertical racks or to walk underneath the platform(s) of the scissor lift(s) after it has been braced, blocked, and/or cribbed. However, in such an arrangement, depending on if the scissor lift has been braced, access underneath the platform is considered a permit required confined space. As such, there is a need for an automated device that braces and/or blocks a scissor lift.

SUMMARY

Scissor lift safety devices, systems for bracing a scissor lift, and methods for operating safety devices for scissor lifts are disclosed. Safety devices for a scissor lift comprise one or more blocks, a bracing structure, and an actuator. The one or more blocks are configured to be fixed relative to a base of the scissor lift. The actuator is configured to selectively translate the bracing structure between a braced position, in which the bracing structure is positioned between the block and a support leg of the scissor lift, and a retracted position, in which the bracing structure is not positioned between the block and the support leg of the scissor lift. In the braced position, the bracing structure is configured to restrict movement of the scissor lift support leg when the support leg translates towards and against the bracing structure.

Methods for operating scissor lift safety devices to restrict movement of a scissor lift comprise receiving a positioning command from a user and, in response to receiving the positioning command, translating the bracing structure between the retracted position and the braced position.

DESCRIPTION

Scissor lifts are work platforms configured to hold weight and translate straight up and down using cross beams (A.K.A support legs) functioning in a scissor-like fashion. In some examples, such as in the manufacturing of an airplane wing, multiple scissor lifts may be arranged in close proximity to one another and/or between vertical supply racks and used to hold components of the airplane wing and/or manufacturing personnel.

Each scissor lift generally comprises a platform, a base, a lift mechanism, and at least two pairs of support legs configured to translate along the base. Each pair of support legs include two legs rotatably coupled to one another at a central pivoting axis that is perpendicular to the length of the leg. The at least two pairs of support legs are operably coupled to an underside of the scissor lift platform on respective first ends and made to translate along the base on respective second ends in response to an actuating of the lift mechanism. By translating the support legs along the base, the scissor lift is transitioned along a central axis of the base between a vertically extended position in which the support legs are disposed at a minimum distance to the central axis of the scissor lift base and a collapsed position in which the support legs are disposed at a maximum distance from the central axis of the base.

Various components of the scissor lift, such as the lift mechanism, which is configured to translate the platform up and down, include a plurality of components that, if following the Occupational Safety and Health Administration (OSHA) guidelines, require routine inspection and maintenance. However, it is typical in scissor lift construction to arrange the majority of components needing routine inspection and/or maintenance below the platform such that the components of the lift mechanism are inaccessible when the scissor lift is in the collapsed position. As such, to perform maintenance and/or an inspection of the lift mechanism or other components, it is often required for the scissor lift to be in the vertically extended position. To ensure that scissor lifts do not unintentionally translate back along the base into the collapsed position during maintenance or inspection, manufacturers of scissor lifts often include a manually installed cribbing and/or bracing system configured to arrest movement of the scissor lift.

In some examples, a cribbing and/or bracing system of a scissor lift includes one or more bracing recesses disposed in the lateral sides of the base and one or more blocks configured to be manually placed in and received by the one or more bracing recesses of the base to arrest movement of the support legs in the event of an unplanned collapse of the scissor lift. For this type of cribbing and/or bracing system, it is often the case that each of the one or more bracing recesses are arranged in the base within the translating region (i.e., the region between the support legs minimum distance and maximum distance) adjacent the minimum distance location at which the support legs are disposed when the scissor lift is in the vertically extended position. As such, when the bracing blocks are placed within the one or more bracing recesses, they restrict the support leg(s) of the scissor lift from translating out of the vertically extended position. While the manually placed blocks accomplish the task of arresting movement of the support legs, the installation of the blocks creates a safety concern for the person manually installing the blocks.

In general, scissor lift safety devices in accordance with the present disclosure are configured to selectively arrest movement of the scissor lift without exposing a maintenance person or engineer to unnecessary dangers.

Safety devices for scissor lifts are schematically represented inFIG.1. Generally, inFIG.1, elements that are likely to be included in a given example are illustrated in solid lines, while elements that are optional to a given example or correspond to a specific example are illustrated in dashed lines. Elements that may be considered to be the environment in which a given example is arranged are illustrated in dash-dot lines. However, elements that are illustrated in solid lines are not essential to all examples of the present disclosure, and an element shown in solid lines may be omitted from a particular example without departing from the scope of the present disclosure.

A standard scissor lift12includes at least a platform, a base14having a central vertical axis along which the platform moves, a lift mechanism, and one or more support legs16. When actuated by a user, the support legs16, by way of the lift mechanism, are made to translate along the base14to transition the scissor lift between a vertically extended position in which the support legs16are disposed at a minimum distance from the central axis of the base14and a collapsed position in which the support legs16are disposed at a maximum distance from the central axis of the base14. The region of the base14within which the support legs16are made to translate is called a translating region92.

As schematically represented inFIG.1, safety devices10include at least a block18, a bracing structure20, and an actuator22. The block18is configured to be fixed relative to the base14of the scissor lift12. The actuator22is configured to selectively translate the bracing structure20between a braced position24(illustrated in solid lines inFIG.1), in which the bracing structure20is operatively positioned between the block18and the support leg16of the scissor lift12, and a retracted position26(illustrated in dash-dot-dot lines inFIG.1), in which the bracing structure20is not positioned between the block18and the support leg16of the scissor lift12.

The block18may include at least a base contacting surface60configured to be fixedly coupled to the base14and a device engagement surface64configured to selectively engage with the bracing structure20. The block18is configured to be fixedly coupled to the base14within the translating region92(i.e., region of the base14between the support legs16minimum distance position and maximum distance position) by way of the base contacting surface60. In some examples, one or more blocks18are coupled to the base14adjacent the minimum distance position and within the translating region92. The blocks18may include any suitable structure configured to selectively engage the bracing structure20within the translating region92.

In some examples, the device engagement surface64of the blocks18includes a first ramped surface that is angled relative to the base14. The first ramped surface may comprise an upper surface of the block18. As such, the device engagement surface64comprises the upper surface of block18that is angled relative to the base14and configured to selectively engage the bracing structure20in response to a collapse of the scissor lift12.

The bracing structure20may include any suitable structure configured to selectively interface with the blocks18, the base14, and/or the support leg16of the scissor lift12to arrest movement of support leg16that may occur in response to an unplanned collapsing of the scissor lift. In some examples, the bracing structure20is configured to interface with the base14of the scissor lift12by way of the blocks18. The bracing structure20is operably coupled to the actuator22such that the actuator22is configured to selectively translate the bracing structure20towards or away from the scissor lift12to arrest or permit movement of the support leg16of the scissor lift12. “Bracing,” “blocking,” and “cribbing” (and conjugations thereof) may be used interchangeably herein to describe structures used to temporarily support and/or secure a support leg16of the scissor lift12.

In some examples, the actuator22is configured to selectively translate the bracing structure20between the braced position24and the retracted position26. In the braced position24, the bracing structure20restricts the scissor lift12from collapsing and/or translating into the collapsed position by engaging with the base14of the scissor lift12within the translating region92to prevent the support leg16of the scissor lift12from moving out of its minimum distance position. In some examples, the bracing structure20includes one or more bracing members66configured to interface with the block18, the base14, and/or the support leg16of the scissor lift, and an attachment member68coupled to the one or more bracing members66. The attachment member68is configured to operably couple the one or more bracing members68to the actuator22.

The bracing structure20may further include at least a first contacting surface70configured to selectively engage the device engagement surface64of the block18and/or a second contacting surface72configured to selectively engage a bottom end of the support leg16in the event of a collapse of the scissor lift. For example, in response to a failing of a lift mechanism of the scissor lift, the support legs16are pushed outwards by the gravitational load of the scissor lift platform as it falls and selectively engage with the second contacting surface72of the bracing structure20. In response to the support legs16engaging with the second contacting surface72, the bracing structure20is pushed in a direction towards the block18such that the first contacting surface70of the bracing structure20is brought into contact with the device engagement surface64of the block18, thereby stopping any further movement of the support leg16and the bracing structure20. The bracing structure20may include a structure having any size or shape suitable for interfacing with the blocks18and a bottom end of the support leg16. The bracing structure20may comprise any heavy, durable, and/or resilient material having a high load capacity capable of withstanding and cushioning the load of the scissor lift.

The actuator22may include any actuator suitable for transitioning the bracing structure20between the braced position24and the retracted position26without interfering with the movements of the scissor lift, such as, a pneumatic, hydraulic, electronic, linear, rotary, cam, and/or any other suitable types of actuators. In some examples, the actuator22further includes a control unit80in communication with an external user interface82and configured to control the actuator22according to signals received from the external user interface82. As such, the control unit80is configured to receive a signal representing a command to move the bracing structure20into either the braced position24or the retracted position26, and in response to receiving the signal, operate the actuator22according to the received signal.

The control unit80may be any suitable device or devices that are configured to perform the functions of a controller discussed herein. For example, the control unit may include one or more of an electronic controller, a dedicated controller, a special-purpose controller, a personal computer, a special-purpose computer, a display device, a logic device, a memory device, and/or a memory device having non-transitory computer readable media suitable for storing computer-executable instructions for implementing aspects of systems and/or methods according to the present disclosure

As schematically illustrated in dashed lines inFIG.1, the safety device10also may include one or more rollers28operatively coupled to the bracing structure20and configured to assist in translating the bracing structure20between the braced position24and the retracted position26. The one or more rollers28may have any shape or size suitable for rolling across a surface and moving the bracing structure20between various positions.

As also schematically illustrated in dashed lines inFIG.1, the safety device10also may include one or more roller-surface bodies32positioned adjacent to a lateral side of each of the one or more blocks18. Each of the one or more roller-surface bodies32have a front end33and a rear end35arranged opposite one another and a top side37that extends the entire distance between the front and rear ends. Each of the one or more roller-surface bodies32further includes a roller surface30disposed along the top side37of the roller-surface body32and shaped to at least partially receive a roller28of the one or more rollers28. As such, the roller surface30may comprise the entire length of the top side37such that the roller surface30spans the entire distance between the front end33and the rear end35of the roller-surface body32. In some examples, the roller-surface body32further includes at least one angled surface31disposed at the front end of the roller-surface body32, and the roller surface30comprises the at least one angled surface31. The at least one angled surface31may comprise a surface that runs parallel to the device engagement surface64of the block18. The roller28is configured to roll along the roller surface30when the bracing structure20is translated between the braced position24and the retracted position26.

In relation to the roller-surface body32, the braced position24denotes the location of the bracing structure20when the bracing structure is disposed adjacent the front end of the roller-surface body32, while the retracted position26denotes a position in which the bracing structure20is disposed adjacent the rear end of the roller-surface body32.

As also schematically illustrated in dashed lines inFIG.1, the safety device10also may include at least one sensor36in communication with the control unit80and configured to detect whether the bracing structure20is in the braced position24. The at least one sensor36may be disposed at any location relative to the scissor lift that enables the at least one sensor36to detect whether the bracing structure20is in the braced position. In some examples, the sensor36is arranged on the base14spaced from the front end of the roller-surface body32and adjacent to the one or more blocks18, such that the sensor36can detect when the bracing structure20is in the braced position24.

In some examples, the roller28is disposed at a bottom edge of the bracing structure20, such that when the bracing structure is in the braced position24, the roller28is disposed next to the sensor36. As such, in some examples, the sensor36may be configured to detect when the bracing structure20is in the braced position24by sensing the presence or absence of the roller28. In response to determining that bracing structure20is in braced position24, the sensor36is configured to transmit a signal of success to the control unit80and/or the user interface82, and in response to determining that the bracing structure20is not in the braced position24, the sensor36is configured to transmit a signal of failure to the control unit and/or user interface.

As also schematically illustrated in dashed lines inFIG.1, the safety device10also may include a suspension structure38and at least one spring34that is operatively coupled to the roller-surface body32by way of the suspension structure38. The at least one spring34is configured to bias the roller-surface body toward the bracing structure20when the bracing structure20is in the braced position24.

The at least one spring34may comprise any suitable spring capable of exerting enough force to bias the roller-surface body32towards the bracing structure20when the bracing structure is in the braced position24.

As also schematically illustrated in dashed lines inFIG.1, the safety device10also may include a support slab56and/or a leveling slab58configured to be disposed between the scissor lift12and a surface (i.e., the ground) on which the scissor lift is arranged. The support slab56is configured to be arranged under the same end of the scissor lift12on which the safety device10is installed, such that components of the safety device10may be coupled to the support slab56through openings in the base14of the scissor lift. The leveling slab58is configured to be arranged under an end of the scissor lift12that is opposite the end on which the safety device10is installed. In some examples, the support slab56and/or the leveling slab58are further configured to couple with the base14of the scissor lift such that both the scissor lift and the components of the safety device10are mounted to the same support slab56.

Turning now toFIGS.2-13, an illustrative non-exclusive example of safety device100or portions thereof are depicted. Where appropriate, the reference numerals from the schematic illustration ofFIG.1are used to designate corresponding parts of the example ofFIGS.2-13; however, the examples ofFIGS.2-13are non-exclusive and do not limit the safety devices10to the illustrated embodiment ofFIGS.2-13. That is, the safety device100may incorporate any number of the various aspects, configurations, characteristics, properties, etc. of the safety devices10that are illustrated in and discussed with reference to the schematic representations ofFIG.1and/or the embodiment ofFIGS.2-13, as well as variations thereof, without requiring the inclusion of all such aspects, configurations, characteristics, properties, etc. For the purpose of brevity, each previously discussed component, part, portion, aspect, region, etc. or variants thereof may not be discussed, illustrated, and/or labeled again with respect to the example ofFIGS.2-13; however, it is within the scope of the present disclosure that the previously discussed features, variants, etc. may be utilized with the example ofFIGS.2-13.

As seen inFIGS.2-13, the safety device100is an example of the safety device10described above.FIGS.2-3, and7-13depict the safety device100installed on a scissor lift12(i.e., environment) whileFIGS.4-6depict just safety device100.

As discussed above, a standard scissor lift12includes at least a platform, a lift mechanism, one or more support legs16, and a base14having a first end52, a second end54opposite the first end, and central vertical axis along which the platform moves. A manufacturer-provided safety system for a scissor lift12often includes a pair of bracing recesses90disposed on opposite sides of the base14within the translating region and configured to receive a manufacturer-designed block to arrest movement of the support legs16when the scissor lift is in the vertically extended position.

FIGS.2-3depict the safety device100installed on the scissor lift12(i.e., environment) at the first end52of the base14.FIG.4depicts the components of the safety device100. The safety device100includes one or more blocks118, a bracing structure120, and an actuator122.

The safety device100further includes a support slab156and a leveling slab158configured to be disposed under the first end52and the second end54of the scissor lift12, respectively, between the scissor lift and the ground. The support slab156may include a plurality of apertures and/or protrusions coupled with mounting hardware of the scissor lift12and/or coupled with one or more other components of the safety device100, such that the scissor lift and/or other components of the safety device100are fixedly coupled to support slab156.

As depicted inFIGS.3-4, blocks118are disposed within the existing bracing recesses90of the base14and fixedly coupled thereat. As such, each block118has a base contacting surface160coupled to the base14, a slab contacting surface fixed to the support slab156, and/or a device engagement surface164engaged with bracing structure120.

The device engagement surface164of each of the one or more blocks118comprises a first ramped surface that is angled relative to the base14such that when the one or more blocks118are disposed within the bracing recesses90of the scissor lift12, the device engagement surface forms a ramp that extends diagonally from a bottom front edge of the bracing recess to a top rear edge of the bracing recess. As such, the one or more blocks118each comprise a right-angle triangular prism where a vertical rectangular side of the prism is the base contacting surface, a horizontal rectangular side of the prism is the slab contacting surface, and the diagonal rectangular side of the prism is the device engagement surface164. In other examples, the one or more blocks118have any shape or size suitable for positioning within a bracing recess and interfacing with the bracing structure120.

As shown inFIG.4, the bracing structure120includes one or more brace members166and at least one attachment member168coupled to the one or more brace members166. Each of the one or more brace members166include at least a first contacting surface170configured to selectively engage the device engagement surface164of the block118and a second contacting surface172configured to selectively interact with a bottom end of the support leg16. In the example ofFIGS.2-13, the bracing structure120includes a pair of brace members166, each brace member166having a first contacting surface170comprising a pair of contact structures170A and170B. Contact structures170A and170B may have any correlating shape or size that, when together with the shape and size of the one or more blocks118, are sized to fit within the bracing recesses of the base14. As shown inFIG.4, the contact structures170A and170B have an upside-down teardrop-shaped cross-section, such that each contact structure170A and170B has a large rounded top section and smaller more pointed bottom section that extends downwards in a first direction from the top section.

The second contacting surface172is disposed between and fixedly coupled to inner surfaces of the top section of the contact structures170A and170B such that the contact structures170A and170B are spaced from one another by the second contacting surface172extending in a second direction transverse to the first direction. The Contact structures170A and170B further comprise apertures disposed in the top section of the contact structure and configured to receive and fixedly couple the second contacting surface172to the contact structures170A and170B of the first contacting surface170.

The attachment member168includes a main crossbar192and one or more arms194extending transversely from the main crossbar. Each of the one or more arms194have a first end transversely coupled to the main crossbar192and a second end coupled to a rear top side of a contact structure170A or170B of each first contacting surface170, such that each of the one or more arms194extends from the top section of the contact structure170A or170B in a third direction that is also transverse to the second direction. The attachment member168further includes supportive beams configured to be fastened across pairs of the one or more arms194to add rigidity to the attachment member168.

The contact structures170A and170B of the first contacting surface170further include a block-contacting surface171disposed on a rear side of the lower portion of the contact structure to selectively engage the device engagement surface164of the block118. The block-contacting surface171extends on the rear side of the contact structures170A and170B between the one or more arms194and the pointed end of the contact structures170A and170B.

The safety device100further includes a roller128operatively coupled to each bracing structure120to assist in translating the bracing structure120between the braced position24and the retracted position26(seeFIGS.5-6).

The brace member166of the bracing structure120is operably coupled to the actuator122by way of the attachment member168. The actuator122comprises at least a guide rail174, a guide block176configured to translate along the guide rail174, and an attachment structure178fixedly coupled to the guide block176, such that the attachment structure178translates together with the guide block176along the guide rail174. The attachment structure178of the actuator122receives the at least one attachment member168of the bracing structure120to operably couple the bracing structure120to the actuator122. As shown inFIGS.2-13, the attachment structure178includes one or more slots that receive a middle portion of the main crossbar192, such that the attachment structure178is pivotably coupled to the attachment member168of the bracing structure120.

As such, the actuator122selectively translates the bracing structure120between a braced position124(FIG.5), in which the bracing structure120is operatively positioned between the block18and the support leg16of the scissor lift12, and a retracted position126(FIG.6), in which the bracing structure120is not positioned between the block18and the support leg16of the scissor lift12. In the braced position124, the bracing structures120restrict the scissor lift12from collapsing and/or translating into a collapsed position.

As shown inFIGS.5and6, each attachment member168of the bracing structure120rotates, or pivots, within the attachment structure178of the actuator122in response to the translation of the bracing structure120between the braced position124and the retracted position126.

The safety device100further includes roller-surface bodies132disposed adjacent a lateral side of each block118. A roller-surface body132comprises a structure that includes a front end33and a rear end35arranged opposite one another, and a top side that37extends the entire distance between the front and rear ends. The roller-surface body132further includes at least one angled surface disposed at the front end of the roller-surface body132. The angled surface of the roller-surface body132extends parallel with device engagement surface164of the block118. Each of the one or more roller-surface bodies132further have a roller surface130disposed along the top side37of the roller-surface body132and shaped to at least partially receive a roller128of the one or more rollers128. The roller surface130includes the angled surface and/or a surface of the top side37of the roller-surface body132. The retracted position126(FIG.6) is further defined as a position of the bracing structure120at which the rollers128and/or the first contacting surface170of the bracing structure120are disposed on the roller surface130adjacent the rear end of the roller-surface body132.

The structure of the roller-surface body132is sized such that the one or more rollers128translate from a position above a max height of the base14(FIG.7) to a position below the max height of the base14(FIG.8) by rolling along the roller surface130. In other words, the bracing structure120is disposed above the max height of the base14when in the retracted position126and is disposed below the max height of the base14when in the braced position124. The at least one attachment member of the bracing structure120is configured to pivot within the attachment structure178of the actuator122in response to the rollers128rolling along the roller surface130to translate the bracing structure from the retracted position, above the max height of the base14, to the braced position, below the max height of the base14, and vice versa. As such, the roller-surface body132functions as a ramp that facilitates the placement and removal of the bracing structure120over the base14of the scissor lift12.

FIG.7depicts the safety device100installed on a scissor lift12with the bracing structure120in the retracted position126. The structure of the roller-surface body may further be sized such that when disposed adjacent the lateral side of the block118and/or an outer surface of the base14, the rear end of the roller-surface body132extends past the first end52of the scissor lift base14. In the retracted position126, the rollers128and/or the first contacting surface170of the bracing structure120is disposed adjacent the rear end of the roller-surface body132and thus past the first end of the base14, such that all components of the bracing structure120are disposed outside of the scissor lift structure. With an entirety of bracing structure120out of the way, the scissor lift12is permitted to translate into the collapsed position without any interference from components of the safety device100. Accordingly, as depicted inFIG.7, the safety device100does not interfere with any movement of the scissor lift when the bracing structure120is in the retracted position126.

The safety device100further includes a sensor136that detects when the bracing structure120is in the braced position. The sensor136is disposed on one of the support slabs156at a position adjacent to one of the rollers128when the bracing structure120is in the braced position124. As such, the sensor136detects when the bracing structure120is in the braced position124by sensing the presence or absence of the roller128. In response to sensing the presence of the roller128within the braced position124, the sensor136transmits a confirmation signal to a user and/or to the control unit80in communication with the user. The sensor136further transmits a signal of failure to the user and/or the control unit80in communication with the user in response to not sensing the presence of the roller128within the braced position124.

FIG.11is a sectional cut-away view of the safety device100and the scissor lift12along plane11inFIG.10, depicting the structural relationship between components of the safety device100and the scissor lift12prior to a scissor lift collapse when the bracing structure120is in the braced position124. The safety device100is a system configured to prevent a complete collapse of a scissor lift in the event of a lift mechanism failure. As such, the load bearing components (e.g., the blocks118, the bracing structure120) of the safety device100only hold a load of the scissor lift12in response to a failing of the scissor lift. Accordingly, to avoid unnecessary stress to the safety device100, the bracing structure120is only translated into the braced position124in response to the scissor lift being placed into the vertically extended position at which the support legs16are disposed at a minimum distance from the central axis of the base14. As shown inFIG.11, in the braced position, the bracing structure120is disposed between and spaced from the block118and the support legs16such that the bracing structure120only engages with the support legs16in response to an increase in the distance between the support legs16and the central axis of the base14. The roller-surface body132is disposed adjacent and set back from the block118and/or the outer surface of the base14such that the angled portion of the roller surface130that runs parallel to the device engagement surface164of the block118is spaced from the device engagement surface (seeFIG.11). The angled portion of the roller surface130is spaced from the device engagement surface164by a distance less than a radius of the roller128. By spacing the roller-surface body132a distance less than a radius of the roller128away from the block118, the bracing structure120, by way of the rollers128, is permitted to translate between the braced position and retracted position without the block contacting surface171of the bracing structure120coming into contact with the block118. As such, prior to a scissor lift collapse, the block contacting surface171of the bracing structure120, in the braced position, is spaced from the device engagement surface164of the block118(seeFIG.11) while the rollers128operably coupled to the bracing structure120are in contact with the roller-surface body132.

The roller-surface body132is operably coupled to the support slab156and/or the base14by a suspension structure138.FIGS.12-13depict the suspension mechanism and composition of the suspension structure138. The suspension structure138includes at least a spring134having a first end and a second end, a first spring-contacting member144, a rail140, and a sliding member142configured to mount and move the roller-surface body132along the rail. The rail140is coupled to the support slab156and/or the base14adjacent the roller-surface body132and arranged in parallel with both the roller-surface body and the base such that the sliding member142of the suspension structure138and the guide block176of the actuator122translate in the same direction. When arranged in parallel with the base14, the rail140has a front-end proximate the block118and a rear-end proximate the first end52of the base14.

The first spring-contacting member144includes a structure with an L-shaped cross section having a short rectangular front surface and a long rectangular back surface. As shown inFIGS.12-13, the first spring-contacting member144is disposed at, and in-line with, the rear end of the rail140and orientated such that the long rectangular back surface is adjacent the rear end of the rail140. The first spring-contacting member144further includes a first contacting face disposed in a middle portion of the long rectangular back surface and configured to couple with the first end of the spring134. In other examples, the first spring-contacting member may be any suitable structure for operably coupling to the spring134and fixedly coupling to the support slab156and/or the base14.

The sliding member142includes at least one or more sliding portions146and a mounting portion148. The mounting portion148is transversely coupled to the one or more sliding portions146on a first side of the one or more sliding portions146that faces the roller-surface body132. The mounting portion148is further coupled to the roller-surface body132to mount the roller-surface body132to the sliding member142. The sliding member142further includes a second spring-contacting member150coupled to a second side of the sliding portion146, the second side of the sliding portion146consisting of a rearmost surface with a plane orthogonal to a plane of the first side of the one or more sliding portions146. The second spring-contacting member150extends vertically from the second side of the one or more sliding portions146and includes a second contacting face configured to couple with the second end of spring134.

The spring134is disposed between the first spring-contacting member144and the second spring-contacting member150and coupled to the first contacting face and second contacting face, such that the spring134is configured to bias the sliding member42, and thus the roller-surface body132, toward the bracing structure120when the bracing structure is in the braced position. The spring134bias's the roller-surface body132towards the bracing structure120such that the roller surface130of the roller-surface body132is disposed at a position between the device engagement surface164of the block118and the block contacting surface171of the bracing structure120.

By biasing the roller-surface body132into position between the block118and the bracing structure120, the spring134holds roller-surface body132in an arrangement that keeps the bracing structure120out of contact with the block118when the bracing structure120is translated between the retracted and engaged positions. The spring134that keeps the bracing structure120out of contact with the block118is further configured to compress in response to the support leg16of the scissor lift12engaging with the bracing structure120during a collapse of the scissor lift. In response to the collapse of the scissor lift, the spring134compresses, permitting the roller-surface body132to translate rearwards away from the block118, which in turn allows the bracing structure120to directly engage with the block118.FIG.12depicts a first set of actions that occur in response to a collapse/failing of a scissor lift. A collapse of a scissor lift often occurs in response to a failing of one or more components of a scissor lift system such as the lift mechanism. During a failing of a scissor lift system, the support legs16of the scissor lift12give out and are forcibly translated out of a mostly vertical orientation (minimum distance position from the central axis of the base14) and into a mostly horizontal orientation (maximum distance position from central axis of the base14) causing the platform to fall towards the ground uninhibited. As such, the first set of actions depicted inFIG.12include the support leg16of the scissor lift12being forcibly translated away from the central axis of the base14, and in response to being translated away from the central axis of the base14, the support legs16selectively engage the second contacting surface172of the bracing structure120. By selectively engaging with the second contacting surface172, the load of the scissor lift12is transferred from the support legs16to the bracing structure120.

In response to selectively engaging with the support legs16of the scissor lift, the bracing structure120is pushed in a direction towards the block118and/or the roller-surface body132.FIG.13depicts the second set of actions that occur in response to the collapse/failing of the scissor lift12. As shown inFIG.13, the bracing structure120is brought into contact with the block118, and the roller128is pushed into the roller surface130of the roller-surface body132and exerts a force thereon in response to the second contacting surface172of the bracing structure120engaging with and receiving the load of the scissor lift12from the support legs16. In response to the force exerted by the roller128on the roller-surface body132, the roller-surface body132is translated away from the support leg16of the scissor lift12and towards the actuator122, compressing the spring134. The bracing structure120is permitted to directly contact the block118in response to the translation of the roller surface-body132towards that actuator122.

The spring134is compressed a distance equivalent to the distance between the block-contacting surface171of the bracing structure120and the device engagement surface164of the block118when the bracing structure120is in the braced position. Said differently, the spring134is compressed a distance less than a radius of the roller128. As such, the suspension structure138holds the roller-surface body132in a position that keeps the bracing structure120from engaging with the block118prior to a scissor lift collapse and permits the bracing structure120to engage with the block118in response the collapse of the scissor lift. The suspension structure138may further absorb and reduce the force applied by the bracing structure120to the blocks118, in response to a scissor lift collapse, by cushioning the force transmitted from the bracing structure120to the blocks118.

FIG.14schematically provides a flowchart that represents illustrative, non-exclusive examples of methods of operating a safety device (e.g., safety device10or100) for a scissor lift (e.g., scissor lift) according to the present disclosure. InFIG.14, some steps are illustrated in dashed boxes indicating that such steps may be optional or may correspond to an optional version of a method according to the present disclosure. That said, not all methods according to the present disclosure are required to include the steps illustrated in solid boxes. The methods and steps illustrated inFIG.14are not limiting and other methods and steps are within the scope of the present disclosure, including methods having greater than or fewer than the number of steps illustrated, as understood from the discussions herein.

As seen inFIG.14, a method300includes receiving302a positioning command from a user, translating304to a bracing structure (e.g., bracing structure20,120), determining306the position of the bracing structure, and/or transmitting308a confirmation signal. In some examples, the positioning command is transmitted as a signal and received by a control unit (e.g., control unit80) of the safety device. The positioning command may include a signal indicating a request to translate the bracing structure of the safety device into either the braced position or the retracted position. The user may use a user interface (e.g., user interface82) and/or any other suitable device for communicating a command to the safety device.

Translating304of the method300may include controlling an actuator (e.g., actuator22,122) to translate the bracing structure according to the received positioning command. In response to receiving a positioning command requesting the bracing structure be in a braced position (e.g., braced position24,124), the actuator is configured to push the bracing structure out of a retracted position (e.g., retracted position26,126) and in the direction of support legs (e.g., support legs16) of the scissor lift such that the bracing structure translates along the roller-surface body and into the braced position. Alternatively, in response to receiving a positioning command requesting the bracing structure be in the retracted position, the actuator is configured to pull the bracing structure out of the braced position, up a roller-surface body (e.g., roller-surface body32,132), and into the retracted position.

The safety device may include one or more sensors (e.g., sensor36,136) configured to detect when the bracing structure is in the braced position. In some examples, the determining306further includes querying the one or more sensors for the position of the bracing structure and receiving a response signal from the one or more sensors indicating whether the bracing structure is in the braced position or the retracted position.

In some examples, one or more sensors are disposed adjacent the bracing structure and are configured to detect the presence or absence of a roller (e.g. roller28,128) or a first contacting surface (e.g. first contacting surface70,170) of the bracing structure when in the braced position. In response to determining that the bracing structure is in the braced position, the one or more sensors may further be configured to send a confirmation signal directly to the user and/or to the control unit of the safety device. In some examples, one or more sensors may further be configured to, in response to determining that the bracing structure is not in the braced position, transmit a signal indicating that the bracing structure is not in the braced position.

In response to receiving a signal from the one or more sensors indicating the bracing structure is in braced position, the control unit is configured to transmit the confirmation signal to the user. In some examples the control unit is configured to transmit the signal to the user interface for review by a user. In some examples, the control unit, in response to receiving a signal from the one or more sensors indicating that the bracing structure was determined to not be in the braced position, transmitting a signal indicating that the bracing structure is not in the braced position to the user.

A. A safety device (10) for a scissor lift (12) that comprises a base (14) and a support leg (16) configured to translate along the base (14), the safety device (10) comprising:

a block (18) configured to be fixed relative to the base (14) of the scissor lift (12);

a bracing structure (20); and

an actuator (22) configured to selectively translate the bracing structure (20) between a braced position (24), in which the bracing structure (20) is operatively positioned between the block (18) and the support leg (16) of the scissor lift (12), and a retracted position (26), in which the bracing structure (20) is not positioned between the block (18) and the support leg (16) of the scissor lift (12).

A1. The safety device (10) of paragraph A, further comprising:

a roller (28) operatively coupled to the bracing structure (20); and

a roller surface (30);

wherein the roller (28) is configured to roll along the roller surface (30) when the bracing structure (20) is translated between the braced position (24) and the retracted position (26).

A1.1. The safety device (10) of paragraph A1, wherein the roller surface (30) is biased toward the bracing structure (20) when the bracing structure is in the braced position (24).

A1.1.1. The safety device (10) of paragraph A1.1, further comprising:

a roller-surface body (32) that comprises the roller surface (30); and

a spring (34) operatively coupled to the roller-surface body (32) and configured to bias the roller-surface body (32) toward the bracing structure (20) when the bracing structure (20) is in the braced position (24).

A1.1.1.1. The safety device (10) of paragraph A1.1.1, wherein the roller (28) urges the roller-surface body (32) in a direction away from the support leg (16) of the scissor lift (12) and against a bias of the spring (34) when the support leg (16) translates toward and against the bracing structure (20).

A2. The safety device (10) of any of paragraphs A-A1.1.1.1, further comprising:

a sensor (36) configured to detect when the bracing structure (20) is in the braced position (24).

A2.1. The safety device of paragraph A2, wherein, in the braced position (24) the bracing structure (20) is disposed between and spaced from the block (18) and the support leg (16) of the scissor lift (12).

A3. The safety device (10) of any of paragraphs A-A2.1, wherein, in the braced position (24), the bracing structure (20) is configured to restrict movement of the support leg (16) of the scissor lift (12) when the support leg (16) translates toward and against the bracing structure (20).

A4. The safety device (10) of any of paragraphs A-A3, wherein the block (18) comprises a device engagement surface (64) positioned to engage the bracing structure (20) when the support leg (16) of the scissor lift (12) translates toward and against the bracing structure (20).

A4.1. The safety device (10) of paragraph A4, wherein the bracing structure (20) comprises:

one or more brace members (166), wherein each brace member (166) of the one or more brace members (166) comprises a first contacting surface (70) and a second contacting surface (72), and wherein, in the braced position (24), the first contacting surface (70) is positioned to engage the device engagement surface (64) of the block (18) and the second contacting surface (72) is positioned to engage the support leg (16) of the scissor lift (12) when the support leg (16) translates toward and against the bracing structure (20); and

an attachment member (68) operatively coupled between each brace member (166) and the actuator (22).

A4.1.1. The safety device (10) of paragraph A4.1, wherein the actuator (22) comprises:

a guide rail (174); and

a guide block (176) configured to translate along the guide rail (174) and operatively coupled to the attachment member (68) of the bracing structure (20).

A4.1.1.1. The safety device (10) of paragraph A4.1.1, wherein the actuator (22) further comprises an attachment structure (178) pivotably coupled to the attachment member (68) of the bracing structure (20).

A5. The safety device (10) of any of paragraphs A-A4.1.1.1, wherein the actuator (22) is a pneumatic actuator.

A6. The safety device (10) of any of paragraphs A-A5, further comprising a control unit (80) configured to control the actuator (22) in response to a command received from a user.

A7. The safety device (10) of any of the paragraphs A-A6, wherein the safety device (10) is configured to not interfere with any movement of the scissor lift (12) when the bracing structure (20) is in the retracted position (26).

A8. The safety device (10) of any of paragraphs A-A7, wherein the safety device (10) is configured to be installed on the scissor lift (12) without interfering with any existing structures of the scissor lift (12).

A9. The safety device (10) of any of paragraphs A-A8 in combination with the scissor lift (12), wherein the safety device (10) is operatively installed relative to the scissor lift (12).

B. A method (300) for operating the safety device (10) of any of paragraphs A-A9 to restrict movement of the scissor lift (12), the method (300) comprising:

receiving (302) a positioning command from a user; and

in response to the receiving (302), translating (304) the bracing structure (20) between the braced position (24) and the retracted position (26).

B1. The method (300) of paragraph B when depending from paragraph A2, further comprising:

determining (306), with the sensor (36), if the bracing structure (20) is in the braced position (24); and

responsive to a determination that the bracing structure (20) is in the braced position (24), transmitting (308) a confirmation signal to the user.

C. The use of the safety device (10) of any of paragraphs A-A9 to restrict movement of the scissor lift (12).

As used herein, the term “and/or” placed between a first entity and a second entity means one of (1) the first entity, (2) the second entity, and (3) the first entity and the second entity. Multiple entries listed with “and/or” should be construed in the same manner, i.e., “one or more” of the entities so conjoined. Other entities optionally may be present other than the entities specifically identified by the “and/or” clause, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, a reference to “A and/or B,” when used in conjunction with open-ended language such as “comprising,” may refer, in one example, to A only (optionally including entities other than B); in another example, to B only (optionally including entities other than A); in yet another example, to both A and B (optionally including other entities). These entities may refer to elements, actions, structures, steps, operations, values, and the like.