阅读说明：本技术 清扫器机具 (Cleaner implement ) 是由 约翰·G·利布尔 凯尔·R·伦丁 于 2020-04-20 设计创作，主要内容包括：所公开的实施例包括具有连杆机构(254；354)和悬挂装置的机具(100；100’；100”；200；300),所述悬挂装置被配置成向工具(224；324)提供下压压力以允许所述工具保持与作业表面的期望的接触水平。可调整的偏压构件(278；378)(诸如气囊)向所述连杆机构提供上压压力以减少来自所述工具的作用于所述作业表面上的下压压力。还可以包括减震器(284；384；386)以将所述连杆机构保持在适当位置并且当所述工具正在被运输时限制所述工具的弹跳。(The disclosed embodiments include an implement (100; 100'; 100 "; 200; 300) having a linkage (254; 354) and a suspension configured to provide a hold-down pressure to a tool (224; 324) to allow the tool to maintain a desired level of contact with a work surface. An adjustable biasing member (278; 378), such as an air bag, provides an upward pressure to the linkage to reduce a downward pressure from the tool on the work surface. A shock absorber (284; 384; 386) may also be included to hold the linkage in place and limit bouncing of the implement while the implement is being transported.)

1. An implement (100; 100'; 100 "; 200; 300) configured to be coupled to a power machine (10), the implement comprising:

a power machine interface (210; 310) having a machine mount (212; 312) configured to attach the implement to the power machine;

an implement frame (222; 322);

a tool (224; 324) configured to perform a work task;

a tool holder (270; 370) configured to support the tool;

a linkage (254; 354) coupling the tool to the implement frame through the tool bracket, the linkage configured to allow the tool to move up and down relative to the implement frame; and

an adjustable biasing member located between the implement frame and the linkage and configured to set a pressing pressure on a work surface by the tool.

2. The implement of claim 1, wherein the implement is a sweeper implement and the tool is a broom tool, wherein the tool bracket (270; 370) is configured to cause the broom tool to pivot about a vertical axis (374) to allow the broom tool to tilt under control of a tilt actuator (226 "; 326") such that a first end of the broom tool is located forward of a second end of the broom tool to direct debris toward a side of the power machine.

3. The implement of claim 2, wherein the tool bracket (270; 370) is configured to cause the broom tool to pivot about a longitudinal axis (376) extending in a forward direction of travel of the power machine to allow the broom tool to tilt side-to-side such that one of the first and second ends of the broom tool is vertically higher than the other of the first and second ends of the broom tool when encountering a tilting surface.

4. The implement of claim 1, wherein the linkage is a four-bar linkage, the four-bar linkage comprising:

a first link (358) pivotally attached to the implement frame (222; 322) at a first pivot connection (362) and pivotally attached to a section (356) of the tool carriage (270; 370) at a second pivot connection (366);

a second link (360) pivotably attached to the implement frame at a third pivot connection (364) and pivotably attached to the section of the tool carriage at a fourth pivot connection (368);

the implement frame; and

the tool carrier.

5. The implement of claim 4, wherein the first link is an upper link and the second link is a lower link located below the second link.

6. The implement of claim 1, wherein the adjustable biasing member comprises an air bladder configured to add or evacuate air to increase or decrease pressure within the air bladder to set a depression pressure by the tool on the work surface.

7. The implement of claim 6, further comprising a stop (392) configured to limit travel of the tool (224; 324) by limiting movement of the linkage (254; 354).

8. The implement of claim 7, wherein the stop is located at least partially within the air bladder.

9. The implement of claim 1, further comprising at least one shock absorber (284; 384; 386) coupled between the linkage mechanism and the implement frame and configured to limit bounce of the implement when the implement is being transported by the power machine.

10. A sweeper implement (100; 100'; 100 "; 200; 300) configured to be coupled to a power machine (10), the sweeper implement comprising:

a power machine interface (210; 310) having a machine mount (212; 312) configured to attach the sweeper implement to the power machine;

an implement frame (222; 322);

a broom frame (352);

a rotary actuator (226 '; 326');

a broom (224; 324) supported by the broom frame and coupled to the rotary actuator, the broom configured to rotate about a first axis (328) under control of the rotary actuator;

a linkage (254; 354) coupling the broom frame to the implement frame through the broom bracket, the linkage configured to allow the broom frame and broom to move up and down relative to the implement frame;

a broom bracket (270; 370) configured to support and cause pivoting of the broom frame and broom about a vertical axis (374) and about a longitudinal axis (376), the broom bracket having a vertical pin carried in a bushing having a horizontal dowel capable of engaging a horizontal bushing operably coupled to the linkage; and

a tilt actuator (226 "; 326") coupled between the broom frame and the broom bracket, the tilt actuator configured to pivot the broom frame and broom about the vertical axis such that a first end of the broom is forward of a second end of the broom to direct debris toward a side of the power machine.

11. The sweeper implement of claim 10, wherein said longitudinal axis (376) extends in a forward direction of travel of said power machine, and wherein said broom bracket causes said broom to pivot about said longitudinal axis allowing said broom to tilt side-to-side such that a first end of said broom is vertically higher than a second end of said broom when encountering a tilting surface.

12. The sweeper implement of claim 10, further comprising a four-bar linkage coupling the broom frame to the implement frame through the broom bracket, the four-bar linkage comprising:

a first link (358) pivotally attached to the implement frame (222; 322) at a first pivot connection (362) and pivotally attached to a section (356) of the broom bracket (270; 370) at a second pivot connection (366);

a second link (360) pivotably attached to the implement frame at a third pivot connection (364) and pivotably attached to the section of broom bracket at a fourth pivot connection (368);

the implement frame; and

the broom bracket.

13. The sweeper implement of claim 12, further comprising a biasing member (278; 378) coupled to said four-bar linkage and configured to reduce a depression pressure provided by said broom against a surface.

14. A sweeper implement according to claim 13, wherein said biasing member (278; 378) is configured such that the depression pressure provided by said broom acting on said surface is adjustable.

15. The sweeper implement of claim 10, further comprising at least one shock absorber (284; 384; 386) coupled between said four-bar linkage and said implement frame and configured to limit bouncing of said broom when said sweeper implement is being transported by said power machine.

Background

The present disclosure relates to an implement attachable to a power machine and an attachment for an implement. More specifically, the present disclosure relates to sweeper implements for power machines.

For purposes of this disclosure, a power machine includes any type of machine that generates power to accomplish a particular task or tasks. One type of power machine is a work vehicle. Work vehicles are typically self-propelled vehicles having a work implement that may be manipulated to perform work functions, such as a lift arm (although some work vehicles may have other work implements). Some examples of work vehicle power machines include loaders, excavators, utility vehicles, tractors, and trenchers, to name a few.

Power machines (such as loaders, excavators, and the like) are designed to receive attachable implements (such as buckets and other types of implements) to perform work functions. In some cases, the power machine may provide signals in the form of pressurized hydraulic fluid and/or electrical signals to control functions on the implement. One type of implement commonly used in power machines is known as a rotary broom or sweeper. The rotary sweeper has a broom that rotates about an axis to sweep a surface (such as concrete). Typically, a hydraulic or other motor on one side of the implement drives the rotating broom to rotate the broom about the axis. In the case of hydraulically driven rotary road sweepers, hydraulic hoses are attached to the machine to receive pressurized hydraulic fluid from the machine to drive the broom.

Some rotary sweeper implements include a broom that can be tilted, which advantageously causes the swept up dirt and debris to be pushed to one side. In these rotary sweeper implements, a tilt actuator controls the angle of the broom. The tilt actuator may also be controlled, for example, hydraulically. One of the challenges in operating this type of broom implement is that the broom ideally needs to be able to float (i.e., move up and down) over uneven terrain. Additionally, when the broom is tilted, it is desirable to keep the broom centered with respect to the machine.

The discussion in this background is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.

Disclosure of Invention

This summary and abstract are provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary and the abstract are not intended to identify key features or essential features of the claimed subject matter.

The disclosed embodiments include a rotary road sweeper or broom having a linkage and a suspension configured to provide a hold down pressure to the cleaning head or broom to allow the cleaning head or broom to maintain a desired level of contact with the cleaning surface. In an exemplary embodiment, a linkage of the implement couples the cleaning head or broom to a frame attachable to a power machine. The linkage mechanism may be a four-bar linkage mechanism having an upper link and a lower link, each link being pivotably coupled to a frame and a broom bracket forming part of the four-bar linkage mechanism. The broom bracket has a two-axis pivot joint that allows the broom to rotate about a first or vertical axis so that the broom may be tilted under the power of a tilt cylinder or actuator. The broom bracket also allows the broom to rotate about a second axis (e.g., extending in the machine travel direction) to allow the broom to rotate when encountering an inclined sweeping surface and to traverse the power machine in a side-to-side inclined manner. The linkage mechanism allows the broom to move up and down. A biasing member, such as an air bag, provides an upward pressure to the linkage to reduce a downward pressure from the broom on the sweeping surface. A shock absorber (284; 384; 386) may also be included between the frame and the linkage to hold the linkage in place and limit the bounce of the broom while the broom is being transported.

One general aspect includes an implement (100; 100'; 100 "; 200; 300) configured to be coupled to a power machine (10), the implement comprising: a power machine interface (210; 310) having a machine mount (212; 312) configured to attach the implement to the power machine; an implement frame (222; 322); a tool (224; 324) configured to perform a work task; a tool holder (270; 370) configured to support the tool; a linkage (254; 354) coupling the tool to the implement frame through the tool bracket, the linkage configured to allow the tool to move up and down relative to the implement frame; an adjustable biasing member configured to set a depression pressure to a work surface by the tool.

The implement may include one or more of the following features. An implement that is a sweeper implement and the tool is a broom tool, wherein the tool bracket (270; 370) is configured to cause the broom tool to pivot about a vertical axis (374) to allow the broom tool to tilt under control of a tilt actuator (226 "; 326") such that a first end of the broom tool is located forward of a second end of the broom tool to direct debris toward a side of the power machine.

An implement, wherein the tool bracket (270; 370) is configured to cause the broom tool to pivot about a longitudinal axis (376) extending in a forward direction of travel of the power machine to allow the broom tool to tilt left and right such that one of the first and second ends of the broom tool is vertically higher than the other of the first and second ends of the broom tool when encountering a tilting surface.

An implement, wherein the linkage is a four-bar linkage, the four-bar linkage comprising: a first link (358) pivotally attached to the implement frame (222; 322) at a first pivot connection (362) and pivotally attached to a segment (356) of the tool carriage (270; 370) at a second pivot connection (366); a second link (360) pivotably attached to the implement frame at a third pivot connection (364) and pivotably attached to a section of a tool carriage at a fourth pivot connection (368); the implement frame; and the tool carrier. An implement, wherein the first link is an upper link and the second link is a lower link located below the second link.

An implement, wherein the adjustable biasing member comprises an air bladder configured with air that is added or evacuated to increase or decrease pressure within the air bladder to set the depression pressure to the work surface by the tool.

An implement further includes a stop (392) configured to limit travel of the tool (224; 324) by limiting movement of the linkage (254; 354). An implement, wherein the detent is a polymeric detent located at least partially within the air bladder.

An implement further includes at least one shock absorber (284; 384; 386) coupled between the linkage and the implement frame and configured to limit bounce of the implement when the implement is being transported by the power machine.

General aspects include a sweeper implement (100; 100'; 100 "; 200; 300) configured to be coupled to a power machine (10), the sweeper implement comprising: a power machine interface (210; 310) having a machine mount (212; 312) configured to attach the sweeper implement to the power machine; an implement frame (222; 322); a broom frame (352); a rotary actuator (226 '; 326'); a broom (224; 324) supported by the broom frame and coupled to the rotary actuator, the broom configured to rotate about a first axis (328) under control of the rotary actuator; a linkage (254; 354) coupling the broom frame to the implement frame through the broom bracket, the linkage configured to allow the broom frame and broom to move up and down relative to the implement frame; a broom bracket (270; 370) configured to support and cause pivoting of the broom frame and broom about a vertical axis (374) and about a longitudinal axis (376); and a tilt actuator (226 "; 326") coupled between the broom frame and the broom bracket, the tilt actuator configured to pivot the broom frame and broom about the vertical axis such that a first end of the broom is forward of a second end of the broom to direct debris toward a side of the power machine.

The implement may include one or more of the following features. A sweeper implement, wherein said longitudinal axis (376) extends in a forward direction of travel of said power machine, and wherein said broom bracket causes said broom to pivot about said longitudinal axis allowing said broom to tilt side to side such that a first end of said broom is vertically higher than a second end of said broom when encountering a tilting surface.

A sweeper implement, further comprising a four-bar linkage coupling the broom frame to the implement frame through the broom bracket, wherein the four-bar linkage comprises: a first link (358) pivotally attached to the implement frame (222; 322) at a first pivot connection (362) and pivotally attached to a section (356) of the broom bracket (270; 370) at a second pivot connection (366); a second link (360) pivotably attached to the implement frame at a third pivot connection (364) and pivotably attached to the section of broom bracket at a fourth pivot connection (368); the implement frame; and said broom bracket.

A sweeper implement further includes a biasing member (278; 378) coupled to the four-bar linkage and configured to reduce a depression pressure provided by the broom against a surface. A sweeper implement, wherein said biasing member (278; 378) is configured such that a depression pressure provided by said broom against said surface is adjustable.

A sweeper implement further includes at least one shock absorber (284; 384; 386) coupled between the four-bar linkage and the implement frame and configured to limit bounce of the broom when the sweeper implement is being transported by the power machine.

Drawings

Fig. 1-3 are block diagrams illustrating a representative implement that may practice embodiments of the present disclosure and a functional system of a power machine to which the representative implement may be coupled.

Fig. 4 is a block diagram of an implement of a type similar to the implement shown in fig. 1-3 and including a rotating broom or sweeper work element, according to an exemplary embodiment.

Fig. 5 and 6 are a perspective view and a cross-sectional side view, respectively, of an implement, such as that shown in fig. 4, in accordance with an exemplary embodiment.

Detailed Description

The concepts disclosed in the present discussion are described and illustrated with respect to exemplary embodiments. However, these concepts are not limited in their application to the details of construction and the arrangement of components in the illustrative embodiments, and can be practiced or carried out in various other ways. The terminology in this document is used for the purpose of description and should not be regarded as limiting. As used herein, words such as "including," "comprising," and "having" and variations thereof are meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

The disclosed concept is used to provide an improved rotary road sweeper or broom implement. The implement includes a linkage and a suspension system configured to provide a hold down pressure to the cleaning head or broom to allow the cleaning head or broom to maintain a desired level of contact with a cleaning surface. The linkage of the implement (coupling the cleaning head or broom to a frame attachable to a power machine) may be a four bar linkage. A broom bracket attaching the linkage to the broom has a two-axis pivot joint that allows the broom to rotate about a first or vertical axis so that the broom may be tilted under the power of a tilt cylinder or actuator. The broom bracket also allows the broom to rotate about a second axis (e.g., extending in the machine travel direction) to allow the broom to rotate when encountering an inclined sweeping surface and to traverse the power machine in a side-to-side inclined manner. A biasing member, such as an air bag, provides an upward pressure to the linkage to reduce a downward pressure from the broom on the sweeping surface. A shock absorber interposed between the frame and the linkage holds the linkage in place and limits the bounce of the broom while the broom is being transported.

The disclosed concepts may be practiced on a variety of implements and on a variety of power machines, as will be described below. Representative implements 100, 100', 100 "in which embodiments may be practiced and representative power machines 10 and 10' to which the implements may be operatively coupled are illustrated in diagrammatic form in fig. 1-3 and described below before any embodiments are disclosed. For the sake of brevity, only one implement and power machine combination is discussed in detail. However, as mentioned above, the following embodiments may be practiced on any of a number of implements, and these various implements may be operably coupled to a variety of different power machines. For purposes of this discussion, a power machine includes a frame, at least one work element (in some cases), and a power source capable of providing power to the work element to accomplish a work task. One type of power machine is a self-propelled work vehicle. Self-propelled work vehicles are one type of power machine: comprising a frame, a working element and a power source capable of providing power to the working element. At least one of the work elements is a launch system for moving the power machine under power.

Referring now to fig. 1, a block diagram illustrates a basic system of a power machine 10 that interacts with an implement 100 and is related to basic features of the implement 100, the implement 100 representing an implement into which the embodiments discussed below may be advantageously incorporated. At its most basic level, for purposes of the present discussion, a power machine includes a frame 20, a power source 25, a work element 30, and an implement interface 40 (as shown in fig. 1). On power machines (such as loaders and excavators and other similar work vehicles), implement interface 40 includes an implement bracket 50 and a power port 60. The implement bracket 50 is typically rotatably attached to a lift arm or another work element, and can be fixed to the implement. The power port 60 provides a connection for the implement 100 to provide power from the power source to the implement. Power source 25 represents one or more power sources generated on power machine 10. This may include either or both of pressurized fluid and electrical power.

The implement 100 (which is sometimes referred to as an attachment or attachable implement) has a power machine interface 110 and a tool 120, the tool 120 being coupled to the power machine interface 110. The power machine interface 110 illustratively includes a machine mount 112 and a power port 114 coupled with the power machine 10. Machine mount 112 may be any structure that may be coupled to implement interface 40 of power machine 10. In some embodiments, the power port 114 includes hydraulic and/or electrical couplings. The power port 114 may also include a wireless radio connection, as may be appropriate for a given implement. While both the machine mount 112 and the power port 114 are shown, some implements may have only one or the other as part of their power machine interface 110. Other implements, such as buckets and some simple forklifts, will have no power port 114 at all (see, e.g., fig. 3). Some other forklifts may have actuators that adjust the tines of the actuator vertically, horizontally, rotationally, or by extending the tines of the actuator in response to a power signal received from the power machine 10 at the power port 114.

In the case of a power machine having a particular implement bracket, the machine mount 112 will include a structure complementary to the particular implement bracket. For power machines without an implement bracket, the machine mount includes features (such as bushings) that mount the implement 100 directly to the power machine 10 to receive pins for mounting the implement to a lift arm and an actuator for moving the implement.

For purposes of this discussion, implements may be categorized as simple or complex. Simple implements have no actuated working element. One example of a simple implement is a bucket or forklift without actuatable tines. Complex implements have at least one actuatable element, such as a forklift, with actuatable tines. Complex implements are further divided into complex implements having one actuatable working element and complex implements having multiple working elements. Some complex implements include features of simple implements.

In fig. 1, the implement 100 illustrates a tool 120, the tool 120 being used with a complex implement having a single working element 124. The tool 120 includes a, the frame 122 being coupled to the machine mount 112 or integral with the machine mount 112. The work element 124 is coupled to the frame 122 and is movable in some manner (vertical, horizontal, rotational, extended, etc.) relative to the frame. An actuator 126 is mounted to the frame 122 and the work element 124 and is drivable under power to move the work element relative to the frame. Power is provided to the actuator 126 via the power machine. Power is selectively provided to the actuators 126 from the power machine 10 via power ports 60 and 114 in the form of pressurized hydraulic fluid (or other power source).

Fig. 2 illustrates an implement 100', the implement 100' depicting a complex multi-function implement. Features in fig. 2 that are similarly numbered to features in fig. 1 are substantially similar and will not be discussed here for the sake of brevity. The implement 100' has one or more additional work devices 124 "that are brought out in a box-like fashion. Each work element 124 "has a respective actuator 126", the respective actuator 126 "being coupled to the work element 124" to control movement of the work element 124 ". A control system 130 receives power from the power machine and selectively provides power to the actuators 126' and 126 "in response to signals from operator input devices. The control system 130 includes a controller 132, the controller 132 configured to receive electrical signals from the power machine 10 indicative of operator input device manipulation and to control power to various actuators based on those electrical signals. The controller 132 may provide electrical signals to some or all of the actuators 126' and 126 "to control their functions. Alternatively, the controller 132 may control an optional valve 134, the optional valve 134 in turn controlling the actuation of some or all of the actuators 126' and 126 "by providing pressurized hydraulic fluid to the actuators.

Although not shown in fig. 2, in some cases, controller 132 may receive a signal indicative of operator actuation of an operator input device mounted on the implement, as opposed to the power machine. In these applications, the implement is controlled from an operator position remote from the power machine (i.e., near the implement 100').

Fig. 3 illustrates an implement 100", the implement 100" depicting a simple implement. Features in fig. 3 that are similarly numbered to features in fig. 1 are substantially similar and will not be discussed here for the sake of brevity. The implement 100 "has one or more engagement structures 126", the engagement structures 126 "being fixedly or movably attached to the frame 122". Unlike a work element that is driven by an actuator to move relative to the frame to perform a work function, the engagement structure may engage with a medium to perform work in conjunction with the power machine. For example, a simple bucket has an engagement structure that includes a cutting edge and a defined volume that holds soil or material collected in the bucket. As another example, the tines of a forklift may be mounted to a frame of the forklift implement to engage a pallet. Such a tine may be adjustable but in many cases the tine itself is not movable under power to perform work but instead the engagement formations are movable to engage and support a load to be lifted and/or carried.

The power machine interface may include a machine mount in the form of a generally planar interface plate that is capable of being coupled to an implement bracket on a loader. In embodiments, various types of machine mounts may be used. The power machine interface may also include a power port (e.g., see interfaces 110 and 110' of fig. 1 and 2, respectively) or no power port (such as in the case of the power machine interface 110 "of fig. 3). When the power machine interface includes a power port, the power port may include a hydraulic conduit connectable to a conduit on a power machine so that pressurized hydraulic fluid may be selectively provided to actuators on the implement to actuate the connected work element. The power port may also include electrical connections that may be connected to actuators on a controller (such as controller 132 of fig. 2) and a valve (such as valve 134). The controllers and valves may be included in a control system on the implement, such as control system 130, to control functions thereon.

Referring now to fig. 4, an implement 200 is shown, the implement 200 may be in accordance with the implement illustrated in fig. 1-3 and include features of the implement illustrated in fig. 1-3. In the illustrated embodiment, implement 200 includes a power machine interface 210 and a tool 220. The tool includes a frame 222, the frame 222 being coupled to the power machine interface 210. The power machine interface provides a machine mount 212 and one or more power ports 214 to provide power, for example in the form of pressurized hydraulic fluid, to an actuator 226 of the tool 220. In some embodiments, such as discussed below with respect to fig. 5 and 6, the machine mount 212 may be formed as part of the frame 222 of the tool, but need not be so in all embodiments.

The implement 220 includes a rotary broom/sweeper 224 driven by a rotary actuator 226', such as a hydraulic motor that receives power from the power machine 10. The broom 224 is supported by a bracket 270, the bracket 270 being coupled to the frame 222 by a linkage 254. In an exemplary embodiment, the linkage 254 may be a four-bar linkage. In some embodiments, bracket 270 is configured to provide a two-axis pivot joint that allows broom 224 to rotate about a vertical axis (the Y-axis shown in fig. 5) under power from tilt actuator 226 "to direct debris toward one side of implement 200. The broom bracket 270 also allows the broom 224 to rotate about a second axis (the Z-axis shown in fig. 5) extending forward from the broom (e.g., in the direction of travel of the power machine 10) to allow the broom to tilt side-to-side when encountering a tilted surface.

In some exemplary embodiments, the four-bar linkage 254 coupling the bracket 270 to the frame 222 is comprised of two links, each link pivotably coupled to both the frame and the bracket. Portions of the frame and the bracket then form the remaining links of the four-bar linkage 254. The linkage 254 allows the bracket 270 and the broom 224 to move up and down. A biasing member 278 (e.g., in the form of an air bag) is provided to resist the action of the linkage to reduce the depression pressure provided by the broom on the surface. In some embodiments, the pressure provided by the biasing member for reducing the depression pressure on the broom is adjustable. For example, air may be added to or exhausted from the bladder to increase or decrease the pressure using a bladder biasing member. Further, in some exemplary embodiments, a shock absorber 284 may be coupled between the frame 222 and the linkage 254, such as to a bottom link of the linkage, to hold the linkage in place and limit the bounce of the broom while in transport.

Referring now to fig. 5 and 6, a rotary broom or sweeper implement 300 is shown, the rotary broom or sweeper implement 300 being another specific embodiment of the implement 200 discussed above with respect to fig. 4. Like implement 200, implement 300 includes a rotating broom supported by a linkage configured to provide an amount of depression pressure to the cleaning head to allow the cleaning head to maintain a desired level of contact with the cleaning surface.

As shown in fig. 5 and 6, implement 300 includes a frame 322, which frame 322 is attachable to the power machine through a machine mount 312 of power machine interface 310. Linkage 354 couples the broom 324 to the implement frame 322 through broom frame 352 and broom bracket 370. The broom 324 is rotatably mounted to the broom frame and is configured to rotate about an axis 328 under the power of a rotary actuator 326' (such as a hydraulic motor receiving hydraulic power from a power source 325 on the power machine). The broom frame 352 is in turn mounted to the broom bracket 370.

In some embodiments, linkage 354 is a four-bar linkage having two links 358 and 360, each of which is pivotally attached to the frame 322 and the broom bracket 370. As shown, upper link 358 is pivotally attached to frame 322 at pivot connection 362 and pivotally attached to segment 356 of broom bracket 370 at pivot connection 366. Lower link 360 is pivotally attached to frame 322 at pivot connection 364 and pivotally attached to section 356 of broom bracket 370 at pivot connection 368. The other two links formed by frame 322 and section 356 of broom bracket 370.

The broom bracket 370 includes a 2-axis pivot joint 372, the 2-axis pivot joint 372 allowing the broom 324 and broom frame 352 to rotate about a first axis (e.g., vertical or Y-axis 374) to tilt under power from a tilt actuator or cylinder 326 "interposed between the broom bracket 370 and the broom frame 352. As can be seen in fig. 6, vertically oriented pin 394, positioned for rotation within first bushing 396, is configured to provide rotation about the vertical axis 374. The bushing 396 itself rotates about a second axis 376, which may be a generally horizontally extending axis 376. Rotation of the bushing 396 about the second axis 376 is accomplished by a pin 398, such as a horizontally extending pin, positioned for rotation within one or more bushings 400 coupled to the bracket 370. Like the rotary actuator 326', the tilt actuator 326 "is driven by a power source 325 on the power machine. This tilting about the axis 374 causes one end of broom 324 to move forward of the power machine compared to the other end of the broom to direct debris toward one side of the machine. As discussed, the broom bracket 370 may also rotate about a second axis, such as a longitudinally extending axis or Z-axis 376, that is orthogonal to the vertical axis 374. Such second axis 376 may extend generally in the forward direction of power machine travel and allow the broom frame 352 and broom 324 to tilt side-to-side when encountering a sloped surface (e.g., such that one end of the broom is higher than the other end of the broom). The linkage 354 allows the broom to move up and down as the surface changes.

A biasing member 378, for example in the form of an air bag, is provided to resist the action of the linkage 354 to reduce the depression pressure provided by the broom on the surface being cleaned. As can be seen in the cross-sectional view of fig. 6, the bladder 378 is attached to the frame via a plate 380 on the bottom of the bladder. A top plate 382 or other structure couples the air bag to the top link 358 so that the air bag acts against the top link to drive the broom 324 upward. In an exemplary embodiment, the air bladder 378 may be inflated to different pressures, thereby allowing the biasing force acting on the top link 358 to be adjustable, thus allowing the depression pressure of the broom or other implement on the work surface to be set to different levels for different purposes. For example, to remove dirt or other adherent material from the work surface, the expansion of the bladder 378 may be controlled to allow for greater downward pressure by the tool on the work surface. However, in other applications, such as sweeping sand away from a grass surface, the inflation of the bladder may be controlled to allow the reduction of the depression pressure exerted by the tool on the work surface.

In some exemplary embodiments, a stop 392 is included to limit travel of the tool 324 by limiting movement of the linkage 354. In an exemplary embodiment, the stop may be a polymeric material partially or completely positioned within the bladder 378 (e.g., on the plate 380). In other embodiments, the stop 392 may be positioned outside of the airbag. The downward movement of the tool applied by linkage 354 is limited by a portion of an opposing surface, such as plate 382 or a link (e.g., link 358), that is about to contact the stop.

Also shown in fig. 5 and 6 is an automobile type shock absorber coupled between the frame 322 and the bottom link 360. As shown, shock absorbers 384 and 386 are coupled to the bottom link 360 and a portion of the frame 322 at a location above the bottom link. Shock absorbers 388 and 390 are coupled to the bottom link 360 and a portion of the frame 322 at a location below the bottom link. These dampers apply a force that holds the linkage 354 in place, thereby limiting the bounce of the broom when the implement 300 is being transported while mounted on the power machine.

Although the present disclosure has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, although described in terms of a sweeper implement and a broom implement, the disclosed embodiments may be used with other types of implements, such as implements having a tool carriage and a tool having similar features to those discussed.