SE543800C2

SE543800C2 - A battery lock mechanism for a battery compartment and an electrically powered hand-held work tool comprising such a battery lock mechanism

Info

Publication number: SE543800C2
Application number: SE1951341A
Authority: SE
Inventors: Robert Lerbro
Original assignee: Husqvarna Ab
Priority date: 2019-11-25
Filing date: 2019-11-25
Publication date: 2021-07-27
Also published as: SE1951341A1

Abstract

A battery lock mechanism (700) for a hand-held work tool battery compartment (150), the battery lock mechanism comprising a locking member (710) rotatably supported on a shaft (720), the locking member comprising a leading edge portion (750) arranged to enter a recess (760) formed in the electrical energy source (220) to lock the electrical energy source in position, wherein the leading edge portion (750) has an arcuate form with a curvature corresponding to that of a circle segment with radius (740) corresponding to the distance from the leading edge portion (750) to the center of the shaft (720), and wherein the recess (760) formed in the energy source (220) comprises a surface (770) arranged to engage the leading edge portion (750), wherein the surface (770) has an arcuate form to match that of the leading edge portion (750).

Description

TITLE A BATTERY LOCK MECHANISM FOR A BATTERY COIVIPARTIVIENT ANDAN ELECTRICALLY POWERED HAND-HELD WORK TOOL COIVIPRISINGSUCH A BATTERY LOCK MECHANISM TECHNICAL FIELD The present disclosure relates to electrically powered hand-held workequipment such as cut-off tools and saws for cutting concrete and stone.

BACKGROUND Hand-held work tools for cutting and/or abrading hard materials such asconcrete and stone comprise powerful motors in order to provide the requiredpower for processing the hard materials.

Ease of operation is especially important for work tools used on constructionsites. For electrical work tools, it is desirable that in-field battery change canbe made in an efficient and convenient manner where the battery is easy toinsert in the work tool, where the battery is snugly held in the work tool, andwhere the battery is easily released from the work tool.

To summarize, there are challenges associated with hand-held work tools.

SUMMARY lt is an object of the present disclosure to provide improvements which addressthe above-mentioned issues. This object is obtained by a battery lockmechanism for a work tool battery compartment. The battery lock mechanismcomprises at least one locking member rotatably supported on a shaft, thelocking member comprising a leading edge portion arranged to enter a recessformed in a battery to lock the electrical energy source in position. The leadingedge portion has an arcuate form with a curvature corresponding to that of acircle segment with radius corresponding to the distance from the leading edge portion to the center of the shaft. The recess formed in the battery comprisesa surface arranged to engage the leading edge portion, wherein the surfacehas an arcuate form configured to match that of the leading edge portion.

This battery lock mechanism allows for inserting a battery into the batterycompartment in an effortless manner. The battery lock mechanism thensecurely holds the battery in position until it is to be removed. The arcuate formof the leading edge portion and the matching surface in the recess allows fora convenient release of the battery from the battery compartment.

According to some aspects, the battery compartment comprises at least oneresilient member arranged to urge the electrical energy source into the lockingposition. There is a plane that divides the battery compartment in two parts,where the at least one resilient member is comprised in one part and thelocking member is comprised in the other part such that that the resilientmember pushes onto the battery from a direction to cause a twisting motion or torque.

The at least one resilient member biases the battery into the locked position,thereby providing a more secure fastening of the battery. Also, by arrangingthe resilient member and the locking mechanisms on opposite sides, a twistingmotion by the battery in relation to the battery compartment is obtained, similarto a stuck desk drawer which further secures the battery in the battery compartment.

According to some aspects, the locking member is spring biased towards thelocking position, and operable by means of a lever or push-button mechanism.The biasing allows for an at least partly automatic locking function, while thelever or push-button mechanism can be conveniently operated by a user of thetool, which is an advantage.

Generally, all terms used in the claims are to be interpreted according to theirordinary meaning in the technical field, unless explicitly defined otherwiseherein. All references to "a/an/the element, apparatus, component, means,step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to beperformed in the exact order disclosed, unless explicitly stated. Furtherfeatures of, and advantages with, the present invention will become apparentwhen studying the appended claims and the following description. The skilledperson realizes that different features of the present invention may becombined to create embodiments other than those described in the following,without departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will now be described in more detail with reference to the appended drawings, whereFigure 1 shows an example work tool; Figures 2A-C show views of another example work tool that is not part of thepresent disclosure; Figures 3A-B show views of a work tool cut-off arm that is not part of thepresent disclosure; Figures 4-6 illustrate bellows for guiding an air flow that is not part of thepresent disclosure; Figures 7A-C schematically illustrate a locking mechanism;Figure 8 shows an example work tool with a battery locking mechanism;Figure 9 schematically illustrates details of a battery lock mechanism; Figures 10A-C show views of an example work tool that is not part of the present disclosure; Figure 11 schematically illustrates a fan that is not part of the presentdisclosure; Figure 12 shows an example fan for a work tool that is not part of the present disclosure; and Figure 13 shows an example fan housing that is not part of the present disclosure.

DETAILED DESCRIPTION The invention will now be described more fully hereinafter with reference to theaccompanying drawings, in which certain aspects of the invention are shown.This invention may, however, be embodied in many different forms and shouldnot be construed as limited to the embodiments and aspects set forth herein;rather, these embodiments are provided by way of example so that thisdisclosure will be thorough and complete, and will fully convey the scope ofthe invention to those skilled in the art. Like numbers refer to like elementsthroughout the description. lt is to be understood that the present invention is not limited to theembodiments described herein and illustrated in the drawings; rather, theskilled person will recognize that many changes and modifications may bemade within the scope of the appended claims.

Figure 1 shows a hand-held work tool 100. The work tool 100 in Figure 1comprises a rotatable circular cutting tool 130, but the techniques disclosedherein can also be applied to other cutting tools such as chain-saws, core drills,and the like. An electric motor 140 is arranged to drive the cutting tool. Thismotor is powered from an electrical energy storage device which is arrangedto be held in a battery compartment 150.

The electrical motor generates a substantial amount of heat during operation.To prevent the motor from overheating, a fan 145 is arranged to be driven bythe motor 140. This fan may, e.g., be attached directly to the motor axle, or bysome means of transmission arrangement. The fan generates an airflow which transports heat away from the electric motor, thereby cooling the motor.

The work tool 100 is arranged to be held by a front handle 190 and a rearhandle 195 and operated by a trigger 196 in a known manner. Although notattended to by the present disclosure, it is desirable to minimize vibration in the handles and trigger, since excessive vibration may be uncomfortable foran operator using the work tool 100. Excessive vibration may also reduce thelifetime of tool components such as cable connections and electronics. Toreduce these vibrations, the work tool 100 comprises a first part 110 and asecond part 120 arranged vibrationally isolated from each other. The first part110 comprises an interface for holding the cutting tool 130 and also comprisesthe electric motor 140 arranged to drive the cutting tool. Thus, the first partcomprises the main vibration generating elements of the work tool.

Notably, the second part 120 comprises the handles 190, 195 and the trigger196 and therefore is the part which interfaces with the operator of the work tool100. The second part 120 also comprises the battery compartment 150 forholding the electrical storage device, and the control electronics for controllingvarious operations of the work tool 100.

Since vibration generated in the first part 110 is not transferred, or at least nottransferred in a significant amount, to the second part 120, an operator of thedevice 100 will not be subjected to the vibration, which is an advantage sincehe or she may be able to work for a longer period of time under morecomfortable work conditions.

Vibration is normally measured in units of m/s2, and it is desired to limit toolvibration in front and rear handles below 2.5 m/s2. Tool vibration, guidelinesfor limiting tool vibration, and measurement of the tool vibration are discussedin "VIBRATIONER - Arbetsmiljöverkets föreskrifter om vibrationer samtallmänna ràd om tillämpningen av föreskrifterna", Arbetsmiljöverket, AFS2005:15.

Not being a part of the present disclosure, the work tool 100 comprises a firstpart 110 and a second part 120 arranged vibrationally isolated from each otherby a vibration isolation system arranged to limit front and rear handle vibrationto values below 2.5 m/s2.

Also not being a part of the present disclosure, a cooling air conduit is arrangedto guide a portion of the flow of cooling air 160 from the first part 110 and into the second part 120 for cooling the electrical storage device. This means that the fan 145 is used to cool both the electrical motor 140, and the electrical energy source, which is an advantage since only a single fan is needed.

Herein, a conduit is a passage arranged to guide a flow, such as a flow of air.A cooling air conduit may be formed as part of an interior space enclosed bywork tool body parts, or as a hose of other type of conduit, or as a combination of different types of conduits.

Any control electronics comprised in the second part 120 may also be arrangedto be cooled by the portion of the flow of cooling air 160 which is guided fromthe first part 110 and into the second part 120. Figure 1 schematically showsa cooling flange 180 associated with such control electronics, which coolingflange 180 is optional, i.e., the portion of the flow of cooling air can be used tocool the control unit directly in which case the control unit constitutes thecooling flange. Thus, optionally, the portion of the flow of cooling air 160 fromthe first part 110 and into the second part 120 is arranged to pass a cooling flange 180 associated with a control unit of the hand-held work tool 100. lt may be a challenge to efficiently guide the portion of air 160 from the firstpart and into the second part, at least partly since the first part and the secondpart are arranged vibrationally isolated from each other. Some aspects of thedisclosed work tool solve this challenge by providing bellows or some othertype of flexible air flow conduit between the first part and the second part toguide the portion of air from the fan 145 towards the battery compartment 150.These bellows 170 will be discussed in more detail below in connection toFigures 4-6. Bellows are sometimes also referred to as flexible covers,convolutions, accordions or machine way covers. A hose formed in a flexible material may be used instead of the bellows.

To summarize, Figure 1 schematically illustrates a hand-held work tool 100comprising a first part 110 and a second part 120 arranged vibrationallyisolated from each other. According to some aspects, the first part 110 isvibrationally isolated from the second part 120 by one or more resilientelements. As mentioned above, the features related to vibration isolation are not part of the present disclosure The hand-held work tool may be a cut-off tool as shown in Figure 1, but it canalso be a chain saw or other work tool for cutting hard materials. The first partcomprises an interface for holding a cutting tool 130 and an electric motor 140arranged to drive the cutting tool. The drive arrangement may, e.g., comprisea belt drive or a combination of belt drive and geared transmission. The electricmotor 140 is arranged to drive a fan 145 configured to generate a flow ofcooling air for cooling the electric motor 140. The fan may, e.g., be directlyconnected to the electric motor shaft, or it can be indirectly connected to themotor shaft via some sort of transmission or drive arrangement, like a belt drive or a geared transmission.

The second part 120 comprises a battery compartment 150 for holding anelectrical storage device arranged to power the electric motor 140, and acooling air conduit is arranged to guide a portion of the flow of cooling air 160from the first part 110 and into the second part 120 for cooling the electricalstorage device. The electrical energy source may be a battery, or some typeof fuel-cell or the like.

Figures 2A-C show different views of an example hand-held work tool 200 thatis not part of the present disclosure and is arranged to hold a cutting tool by acutting tool interface 260. The resilient elements separating the first part 110from the second part 120 are here compression springs 210. However, asmentioned above, some type of resilient material members, such as rubberbushings, may also be used as an alternative to the springs or in combinationwith the springs. Leaf springs may also be an option for vibrationally isolatingthe first part 110 from the second part 120.

Figure 2B shows a holder 270 for an extra blade bushing. Cutting blades mayhave varying dimensions when it comes to the central hole in the blade. Someblade holes are 20mm across, while some other holes are 25,5mm across.There are even some markets where blade central holes of 30,5mm arecommon. To allow use with different types of blades, having differentdimensions on the central blade hole, the hand-held work tool 200 comprises a holder 270 arranged on the work tool body for holding a blade bushing. This extra blade bushing preferably has a different dimension compared to the blade bushing mounted in connection to the cutting tool interface 260.

Figure 2A shows an example electrical storage device 220, here a battery,fitted in the battery compartment 150. This battery may be held in position bymeans of a battery lock mechanism which will be discussed in more detail below in connection to Figures 7A-C, 8, and 9.

According to some aspects, the flow of cooling air for cooling the electric motor140 extends transversally 230, 245, 201 through the hand-held work tool, withrespect to an extension plane of the circular cutting tool 130. Here, withreference to Figure 2C, transversally is to be interpreted relative to anextension direction 202 of the work tool extending from the rear handle 195towards the cutting tool and in relation to an extension plane of the cutting tool130 (which is more or less vertical in Figure 2C). Air from the environment issucked into the work tool interior via an air intake 230 on one side of the tooland at least partly pushed out from the work tool interior via a first air outlet245 on the other side of the tool formed in a direction transversal from the airintake 230.

A portion of the air flow sucked into the work tool via the air inlet 230 is guidedvia an air conduit into the second part 120 where it is used to cool the electricalstorage device and optionally also cool portions of electrical control circuitry.With reference to, e.g., Figure 2B, this portion of the air flow is guideddownwards from the fan and then backwards in the tool towards the batterycompartment 150 before it exits the work tool via a second air outlet 250 formed in the second part 120 of the tool. lt is appreciated that the air flow can be directed also in the reverse direction ifthe fan is run in reverse. l.e., the air outlets 245, 250 can also be used to suckcool air from the environment into the work tool 100, 200, and the air intake 230 can be re-purposed to instead allow hot air to exit the work tool.

With reference to Figure 10A, that is not illustrating the present disclosure, theportion of the air flow 160 guided downwards from the fan and then backwards in the tool also exits the work tool via a third air outlet 251 formed inside the battery compartment 151. This third outlet is mainly arranged to cool a battery received in the battery compartment 150.

Figures 3A and 3B illustrates some aspects of the work tool that is not part ofthe present disclosure, wherein the first part 110 comprises a thermallyconductive cut-off arm 240 arranged to support the circular cutting tool 130 ona first end of the cut-off arm 241, and to support the electric motor 140 by asupport surface 330 at a second end of the cut-off arm 242 opposite to the firstend 241. The motor 140 is then arranged to drive the cutting tool via some typeof drive arrangement, such as a belt drive or a combination of belt drive andgeared transmission. The belt is not shown in Figure 3A, only the belt pulley.The support surface 330 represents a relatively large interfacing area betweenthe motor 140 and the cut-off arm 240, which allows for a significant amountof heat transfer from the motor and into the cut-off arm material, at least if theelectric motor comprises a corresponding surface for interfacing with thesupport surface. This heat is then dissipated from one or more cooling flanges320 formed on the cut-off arm 240. Thus, the cut-off arm 240 comprises oneor more cooling flanges 320 arranged to dissipate heat away from the electricmotor 140 via the support surface 330.

This heat transfer arrangement improves the heat dissipation from the motorsince the cooling air flow is more efficiently utilized to transport the heat away from the motor.

The more thermally conductive the cut-off arm is, the more efficient is the heatdissipation. According to some aspects, at least some parts of the cut-off armis formed in a material having a thermal conductivity property above 100 Wattsper meter and Kelvin (W/mK). For instance, at least some parts of the cut-offarm may be formed in aluminum, which has a thermal conductivity of about237 W/mK. lron or steel is another option which would provide the desiredthermal conductivity. The cut-off arm may also be formed in different materials,i.e., one highly thermally conductive material such as copper, magnesium oraluminum can be used for the cooling flanges and another material, such as cast iron or steel, to provide general structural support.

Optionally, the cut-off arm 240 is arranged to at least partially enclose theelectric motor 140, thereby protecting the motor and improving the air flow pastthe motor. According to some aspects, at least 30% of a volume of the electricmotor 140 is enclosed by the cut-off arm 240. Thus, the motor is optionallysignificantly embedded into the cut-off arm, thereby improving both structuralintegrity of the motor and cut-off arm assembly, as well as improving heattransport away from the electric motor.

The cut-off arm 240 and the electric motor 140 may also be at least partiallyintegrally formed. This means that some parts of the electric motor may beshared with the cut-off arm. For instance, a part of the cut-off arm 240 mayconstitute part of the electric motor housing, such as a motor gable facing thecut-off arm. The common part shared between the cut-off arm 240 and theelectric motor 140 may, e.g., be machined or molded. Also, optionally, theelectric motor axle may bear against a surface of the cut-off arm, to improve mechanical integrity. lt is noted that the feature of an at least partially integrally formed cut-off armand electric motor can be advantageously combined with the other featuresdisclosed herein but is not dependent on any of the other features disclosedherein. Thus, there is disclosed herein a cut-off arm 240 and electric motor 140assembly for a work tool 100, where the cut-off arm and the electric motor areat least partially integrally formed.

With reference to Figure 2B, the first part 110 optionally comprises a belt guard115 configured to enclose the interior space 340. As discussed above, aportion of the flow of cooling air is arranged to be guided 310 into the interiorspace 340, thereby increasing an air pressure in the belt guard 115 interiorspace 340 above an ambient air pressure level. The interior space 340 isdelimited on one side by the cut-off arm (discussed below in connection toFigures 3A and 3B), and on the other side by the belt guard 115, whichassumes the function of a lid arranged to engage the cut-off arm to protect thedrive belt among other things. The belt guard 115 comprises an air outlet 245 through which the flow of cooling air exits the interior space. This air outlet 245 11 is configured with an area such that the air pressure in the belt guard 115interior space 340 increases above the ambient air pressure level by a desired amOUnt.

The increase in air pressure in the interior space 340 means that a flow of airwill exit through all openings into the interior space 340, i.e., any cracks andthe like, and not just the air out|et 245. This in turn means that water, dust,debris and s|urry will have to overcome this flow of air in order to enter into theinterior. Thus, accumulation of unwanted material inside the work tool is reduced.

Water inside the interior space 340 may cause the belt drive to slip and istherefore undesirable. The increase in air pressure in the belt guard 115interior space 340 means that less water is able to enter the interior space,which is an advantage. As a consequence, requirements on the belt can bereduced, such that, e.g., belts with a smaller number of ribs can be used.

As noted above, the portion of the flow of cooling air 160 guided from the firstpart 110 and into the second part 120 may pass via a bellows or other flexibleair flow conduit 170 arranged in-between the first 110 and the second 120parts. Figure 4 that does not illustrate the present disclosure shows an example of such bellows 10 in detail.

According to some aspects, the bellows 170 is associated with a Shoredurometer value, or Shore hardness, between 10-70, and preferably between50-60, measured with durometer type A according to DIN ISO 7619-1.

The bellows 170 optionally comprises a poka-yoke feature 410, 420. Thispoka-yoke feature comprises at least one protrusion 410, 420 configured toenter a corresponding recess formed in the first part 110 and/or in the secondpart 120, thereby preventing erroneous assembly of the bellows with the first110 and second 120 parts.

The bellows 170 also optionally comprises at least one edge portion 430, 440of increased thickness. Each such edge portion is arranged to enter acorresponding groove formed in the first part 110 or in the second part 120, thereby fixing the bellows 170 in relation to the first or second part similar to a 12 sail leech fitting into a mast. Figures 5 and 6, that do not i||ustrate the presentdisclosure, schematically i||ustrate a bellows fitted onto the first and secondparts, respectively, by the edge portions.

The bellows i||ustrated in Figure 4 is arranged with a shape that is symmetricabout a symmetry p|ane 450 parallel to an extension direction of the edgeportions 430, 440. Thus, advantageously, the bellows can be assembled withthe first and second parts independently of which side of the bellows that isfacing upwards. |.e., the bellows can be rotated 180 degrees about thesymmetry axis 460 and assembled with the first and second parts.

Figures 7A-C schematically i||ustrate aspects of the battery compartment 150,where the battery compartment comprises a battery lock mechanism 700. Thebattery lock mechanism comprises a locking member 710 rotatably supportedon a shaft 720. The locking member comprises a leading edge portion 750arranged to enter a recess 760 formed in the electrical energy source 220 tolock the electrical energy source in position, wherein the leading edge portion750 has an arcuate form with a curvature corresponding to that of a circlesegment with radius 740 corresponding to the distance from the leading edgeportion 750 to the center of the shaft 720, and wherein the recess 760 formedin the energy source 220 comprises a surface 770 arranged to engage theleading edge portion 750, wherein the surface 770 has an arcuate form tomatch that of the leading edge portion 750.

This way, as the electrical energy source 220 is received in the batterycompartment 150, the locking member is inactive, simply yielding to theelectrical energy source as it enters the compartment. This phase of insertingthe electrical energy source 220 into the compartment 150 by moving it in aninsertion direction 701 is schematically i||ustrated in Figures 7A and 7B. Thelocking member 710 then swings into the recess 760 where it prevents thebattery to be retracted from the battery compartment. The locking position isi||ustrated in Figure 7C. Notably, the arcuate form of the leading edge portion750 allows the locking mechanism to be rotated out of the locking position with 13 less resistance even if there is some friction between the leading edge portion 750 and the surface 770 arranged to engage the leading edge portion 750.

The locking member may be arranged spring biased towards the lockingposition, and operable by means of a lever or push-button mechanism,discussed below in connection to Figures 8 and 9.

According to some aspects, the battery compartment 150 comprises at leastone resilient member 780 arranged to urge the electrical energy source intothe locking position, i.e., urge the electrical energy source in a directionopposite that of the insertion direction 701. The resilient member 780, whencompressed by the electrical energy source, pushes onto the electrical energysource to repel it from the battery compartment 150. This pushing forceincreases the contact pressure between the leading edge portion 750 and thesurface 770 arranged to engage the leading edge portion 750, therebyimproving the holding effect on the electrical energy source.

According to an example, a user inserts a battery into the battery compartmentin an insertion direction. When the battery is inserted all the way, it contactsthe resilient member 780 and the locking member 710 enters the recess 760formed in the electrical energy source 220 to lock the electrical energy sourcein position. The resilient member, when compressed by the battery, pushesback in a direction opposite to the insertion direction. This pushing force fromthe resilient member increases a contact force between the leading edgeportion 750 of the locking member and the surface 770 arranged to engage the leading edge portion 750, to more securely hold the battery in position.

The resilient member 780 optionally comprises any of a resilient material member, a compression spring, and/or a leaf spring.

The resilient member 708 will also eject the electrical energy source 220 ashort distance from the battery compartment 150 when the electrical energysource is released by the locking mechanism 700. Thus, when the bush-buttonmechanism 810 is operated to release a battery, the battery is ejected fromthe battery compartment 150, making it easier to grasp the battery and pull it out from the battery compartment. 14 Figure 7C schematically shows an example of such resilient members 780.The resilient members urge the electrical energy source in direction 702, butthe electrical energy source is prevented from moving in this direction by thelocking member 710 engaging the recess 760. The arrangement of resilientmember 780 and locking member 710 on opposite sides S1, S2, of theelectrical energy source 220 generates a twisting motion 795 or rotationmoment which further increases the holding effect by increasing frictionbetween battery and battery compartment wall, in a manner similar to a stuckcupboard or desk drawer. This further increase in holding effect reducesvibration by the battery since it is now held even more snugly in the battery compartment.

Figure 8 shows an example work tool 800 which comprises the battery lockmechanism 700. The locking member 710 is rotatably supported on a shaft720, where it is allowed to rotate about an axis 820 of rotation. A push-buttonmechanism 810 can be used by the operator to rotate the locking member 710such that it exits the recess, thereby allowing removal of the battery in direction702.

According to some aspects the locking member 710 is spring biased towardsthe locking position. Thus, as an electrical energy source 220 is inserted intothe recess 150, the locking member 710 snaps into the locking position. Thespring bias force can be overcome by the push-button mechanism 810 whenthe electrical energy source is to be removed from the battery compartment.

Figure 9 illustrates details of a battery lock mechanism 700 for a batterycompartment 150. This battery lock mechanism can be used with manydifferent types of tools, i.e., abrasive tools, grinders, chainsaws, drills, cut-oftools and the like. Thus, the battery lock mechanisms disclosed herein are notlimited to use with the cut-off tools discussed above in connection to Figures1-8.

The battery lock mechanism 700 shown in Figure 9 comprises a lockingmember 710 rotatably supported on a shaft 720 and optionally spring biased into a locking position as discussed above. The locking member comprises a leading edge portion 750 arranged to enter a recess 760 formed in theelectrical energy source 220 to lock the electrical energy source in position, asdiscussed above in connection to Figures 7A-C. The leading edge portion 750may have an arcuate form with a curvature corresponding to that of a circlesegment with radius 740 corresponding to the distance from the leading edgeportion 750 to the center of the shaft 720. The recess 760 formed in the energysource 220 comprises a surface 770 arranged to engage the leading edgeportion 750. This surface 770 has an arcuate form to match that of the leadingedge portion 750. Notably, the battery lock mechanism 700 illustrated in Figure9 comprises two locking members 710 separated by a distance. This doublearrangement of locking members improves robustness of the lock mechanism700.

Thus, as explained in connection to Figures 7A-C, an electrical energy sourcesuch as a battery can be inserted into the battery compartment in an insertiondirection 701, i.e., into the compartment 150 shown in Figure 9. At some pointthe locking member is able to enter into the locking position, i.e., it enters therecess 760. ln this position the battery is prevented from moving in a direction702 opposite to the insertion direction 701. However, it may rattle some andmay not be firmly secured. To improve the battery lock mechanism and tobetter hold the electrical energy source in position, one or more resilientmembers 780, such as compression springs or rubber bushings, are arrangedin the battery compartment 150 and/or on the electrical energy source to pushon the electrical energy source as it is inserted all the way into thecompartment. The pushing force increases a contact force between theleading edge portion 750 and the surface 770 configured to engage the leadingedge portion. This increased contact force increases friction to better hold the electrical energy source in position.

According to some aspects, the at least one resilient member 780 and thebattery lock mechanism 700 are arranged at opposite sides S1, S2 of thebattery compartment 150, i.e., there is a plane 910 that divides the batterycompartment in two parts, where the resilient member 780 is comprised in one part and the battery lock mechanism is comprised in the other part. This means 16 that the resilient member or members push onto the electrical battery sourcefrom a direction to cause a twisting motion 795 or torque. This twisting motioncan be compared to a drawer which gets stuck in a cupboard or desk. Theelectrical energy source is then prevented from rattling and is more firmlysecured in the battery compartment 150.

Figures 10A and 10 B show an example work tool 1000 comprising a specialtype of fan 145, not being part of the present disclosure. This fan comprises amember, preferably but not necessarily discoid shaped, arranged on the axleof the electric motor 140 which also constitutes an axis of rotation of the fan.The member extends in a plane perpendicular to the axis of rotation andcomprises two different types of fan portions. A first portion acts as an axialfan and pushes cooling air transversally 201 across the work tool 1000 to coolthe electric motor 140. A second section of the fan acts as a radial fan, alsoknown as a centrifugal fan, to push cooling air downwards and into the secondpart of the work tool in cooperation with a fan scroll matched to the radial fanportion. The fan 145 is schematically illustrated in Figure 11 and an exampleof the fan is shown in Figure 12, the fan not being part of the present disclosure,where the direction of rotation 1130 and the axis of rotation 1140 have beenindicated. Figure 11 also indicates the direction 1145 referred to as 'radiallyoutwards' from the axis of rotation 1140.

Figure 10A shows an example tool that is not part of the present disclosurewhere, the portion of the flow of cooling air 160 from the first part 110 and intothe second part 120 is arranged to enter the electrical energy source 220 viaa third outlet 251 arranged inside the battery compartment 150. Thisconnection to the electrical energy source improves cooling efficiency by bettercooling, e.g., the cells in a battery.

The fan 145 comprises an axial fan portion 1110 arranged peripherally on thefan 145, i.e., circumferentially along the fan disc border as shown in Figure 11and in Figure 12, and a radial fan portion 1120 arranged centrally on the fan145, i.e., radially inwards from the axial fan portion as shown in Figures 11 and 12. Thus, the axial fan portion is arranged radially outwards 1145 in the 17 extension plane from the axis of rotation 1140. The axial fan portion 1110 isarranged to generate the flow of cooling air 1330 for cooling the electric motor140, and the radial fan portion 1120 is arranged to generate the portion of theflow of cooling air 160 from the first part 110 and into the second part 120 forcooling the electrical storage device.

Axial flow fans, or axial fans, have blades that force air to move parallel to theshaft about which the blades rotate, i.e., the axis of rotation. This type of fan isused in a wide variety of applications, ranging from small cooling fans forelectronics to the giant fans used in wind tunnels. The axial fan is particularlysuitable for generating large air flows in straight tube-line conduits, which is the case here when cooling the electric motor 140.

Radial fans, or centrifugal fans, uses the centrifugal power supplied from therotation of impellers to increase the kinetic energy of air/gases. When theimpellers rotate, the gas particles near the impellers are thrown off from theimpellers, then move into the fan housing wall. The gas is then guided to theexit by a fan scroll. A radial fan, compared to the axial fan, is better at pushingcooling air at a pressure passed air conduits with bends and narrow passages,which is the case for the air conduit passing into the second part and towards the battery compartment 150.

According to some aspects, the axial fan and the radial fan are formed asseparate parts mounted on the same motor axle.

The radius of the radial fan may correspond to the radius of the electrical motor gable.

The relationship between the radius of the radial fan and the radius of the fanmay be on the order of 50-70 percent.

Thus, advantageously, the fan illustrated in Figures 10-13 provide bothefficient motor cooling as well as efficient cooling of tool members in thesecond part, e.g., the control unit and the electrical energy source. This isachieved by providing two different types of fans on a single fan member. 18 Figure 10C, that does not illustrate the present disclosure, shows a moredetailed view of the part of the cut-off arm which comprises the one or morecooling flanges 320 arranged to dissipate heat away from the electric motor140 via the support surface 330. The openings 310 for letting air enter theinterior space 340 discussed above can also be seen. The axial fan portion1110 pushes air past the motor and through these holes, thereby cooling the electric motor 140.

The fan 145 may optionally be assembled in a fan housing 1010 exemplifiedin Figure 13 that does not illustrate the present disclosure. The fan housingcomprises at least one opening 1310 arranged peripherally and radiallyoutwards from the axis of rotation 1140 to receive the flow of cooling air 1330from the axial fan portion 1110 for cooling the electric motor 140. The fanhousing also comprises a fan scroll 1320 arranged centrally in the housing tointerface with the radial fan portion 1120 for guiding the portion of the flow ofcooling air 160 from the first part 110 and into the second part 120 for cooling the electrical storage device.

Figure 13 also shows the grooves 1340 and the recesses 1350 for receivingthe bellows 170 with the edge portions 430 and the poka-yoke feature 410illustrated in Figure 4.

The fan discussed in connection to Figures 10A, B, 11, 12, and 13 is not onlyapplicable to the types of work tools disclosed herein. On the contrary, this fancan be used with advantage in any type of work tool where a first flow of coolingair and a second flow is desired. Thus, there is disclosed herein a fan 145 fora hand-held work tool 100, 200, 800, 1000. The fan 145 extends in a planeperpendicular to an axis of rotation of the fan 1140. The fan comprises an axialfan portion 1110 arranged radially outwards 145 from a radial fan portion 1120arranged centrally on the fan 145 with respect to the axis of rotation 1140,wherein the axial fan portion 1110 is arranged to generate a first flow of coolingair for cooling a first hand-held work tool member, and wherein the radial fanportion 1120 is arranged to generate a second flow of cooling air 160 for cooling a second hand-held work tool member. 19 Optionally, the axial fan portion 1110 has an annular shape centered on theaxis of rotation 1140, and wherein the radial fan portion 1120 has a discoidshape centered on the axis of rotation 1140.

There is also disclosed herein a hand-held work tool 1000 comprising the fandiscussed in connection to Figures 10-13, and a fan housing 1010. The fan145 is assembled in the fan housing 1010, which fan housing comprises atleast one opening 1310 arranged peripherally in the fan housing and radiallyoutwards from the axis of rotation 1140 of the fan 145 to receive the first flowof cooling air from the axial fan portion 1110 for cooling the first hand-held worktool member, the fan housing also comprises a fan scroll 1320 arrangedcentrally in the fan housing to interface with the radial fan portion for guidingthe second flow of cooling air 160 for cooling a second hand-held work tool member.

Claims

CLA||\/IS

1. A battery lock mechanism (700) for a work tool battery compartment(150), the battery lock mechanism comprising at least one locking member(710) rotatably supported on a shaft (720), the locking member comprising aleading edge portion (750) arranged to enter a recess (760) formed in a battery(220) to lock the battery in position, wherein the leading edge portion (750) hasan arcuate form with a curvature corresponding to that of a circle segment withradius (740) corresponding to the distance from the leading edge portion (750)to the center of the shaft (720), and wherein the recess (760) formed in thebattery (220) comprises a surface (770) arranged to engage the leading edgeportion (750), wherein the surface (770) has an arcuate form to match that ofthe leading edge portion (750).

2. The battery lock mechanism (700) according to claim 1, comprising aplurality of locking members (710) arranged spaced apart by a distance.

3. The battery lock mechanism (700) according to any one of the claims 1or 2, comprising at least one resilient member (780) arranged to urge thebattery into the locking position, wherein there is a plane (910) that divides thebattery compartment (150) in two parts (S1, S2), where the at least oneresilient member (780) is comprised in one part (S2) and the locking member(710) is comprised in the other part (S1) such that that the resilient member(780) pushes onto the battery (220) from a direction to cause a twisting motion(795) or torque.

4. The battery lock mechanism (700) according to claim 3, wherein theresilient member (780) comprises any of a resilient material member, a rubber bushing, a compression spring, and/or a leaf spring.

5. The battery lock mechanism (700) according to any previous claim,wherein the locking member (710) is spring biased towards the lockingposition, and operable by means of a lever or push-button mechanism (810).

6. A hand-held work tool (100, 200, 800, 1000) comprising an electric motor(140) arranged to drive a cutting tool (130), where the electric motor (140) is powered from a battery (220) which is arranged to be held in a battery 21 compartment (150) that comprises the battery lock mechanism (700) according to any previous claim.