NL2025415B1 - Cab tiliting locking mechanism - Google Patents

Abstract

The present invention pertains to a hydraulic pump unit (1) of a hydraulic cab-tilting mechanism of a truck. The unit comprising a pump that can be manually operated with a lever that is detachably receivable in a receiving member (6), wherein the receiving member is accompanied with a locking mechanism (20) comprising an insert (21) dimensioned to fit into the receiving member and a cover (22) shaped to enclose the receiving member. The cover and insert mutually engage in a locked condition to prevent removing the insert and cover from the receiving member. The cover has a continuously sloping side wall (22s) from a proximal end at a casing (3) housing the pump to a distal end away from the casing. The invention further pertains to a kit of p arts including the insert and the cover for retrofitting a hydraulic pump unit of a truck with a locking mechanism. [FIG 3B]

Description

Title: CAB TILITING LOCKING MECHANISM

TECHNICAL FIELD AND BACKGROUND The present disclosure relates to a hydraulic pumping unit for feeding a hydraulic cab-tilting mechanism of a truck, wherein a locking mechanism is provided to prevent unauthorized operation of the hydraulic cab-tilting mechanism. In particular, the disclosure relates to a locking mechanism comprising a cover and insert portion to prevent unauthorized use of a manual pump lever.

A cab-tilting installation of a truck typically comprises a hydraulic cab-tilting mechanism, e.g. a cylinder, and a pump for feeding hydric fluid to the cab-tilting mechanism. Pump control may be electric but for many vehicles the pump may be controlled manually. Typically manual pump control involves providing an oscillating pump movement via a lever that is suitably inserted in a receiving member that is connected to the pump. By handling the lever the hydraulic cab-tilting mechanism may be activated even when other systems, e.g. electrical systems, of the truck are disabled. The receiving member typically protrudes out of a housing of the hydraulic pump and 1s located at an outside location on the truck and is designed to be operable with relative ease, e.g. by the driver or a service engineer, to allow access to the engine compartment.

A problem associated with manual pump control includes a possibility of unauthorized access, e.g. by individuals carrying a lever, e.g. a rod, or other tool to actuate the receiving member. Unauthorized access may be related to vandalism and/or theft, e.g., theft of engine parts. Unauthorized (partial) cab tilting may further be related to cargo theft, e.g. by roadside robbers, as security measures built into the truck typically prevent a driver from leaving a potential crime site while the cab is in a (partially) tilted position.

To prevent unauthorized cab tilting a number of security measures are known. These include provision of a remotely controllable electric system, e.g. with a switch located within the cab. Such systems include electronic locks providing an electric signal that prevents cabin tilting. A problem of such system includes that such measures may be relatively easily circumvented by malicious individuals, e.g. by cutting wiring and/or spoofing of signals. Alternatively, or in addition, an alarm system may be provided, e.g. an audible alarm, but such systems do not physically prevent unauthorized pump access and are comparatively costly.

Known mechanical locks, e.g. as described in relation to the pump unit disclosed in US20090057044 can help prevent more casual unauthorized individuals from operating the pump, but may be less effective against more persistent individuals, e.g. thieves, since the lock and/or the receiving member remain accessible allowing tampering with the lock and/or forcing of the receiving member.

SUMMARY Aspects of the present disclosure relate to ahydraulic pump unit for feeding a hydraulic cab-tilting mechanism of a truck. The hydraulic pump unit comprising a casing enclosing a hydraulic pump that can be manually operated with a pump lever that is detachably receivable in a receiving member that is located outside the casing and that is connected to the pump via a pump axle that protrudes from the casing. The hydraulic pump unit, and in particular the receiving member, is accompanied with a locking mechanism. An unlocked and locked condition respectively allow and disallow manual operation of the hydraulic pump, e.g., via the pump lever. The locking mechanism comprises, or essentially consists of, an insert and a cover.

The insert includes a key-operable lock. The lock allows reversibly switching the locking mechanism between the locked and the unlocked condition. The insert is dimensioned to be reversibly insertable into the receiving member at least when the locking mechanism is in an unlocked condition. The insert is further dimensioned to block the receiving member from receiving a pump lever so long as the receiving member comprises the insert, that is while the insert is inserted into the receiving member. The insert can fulfill its task of blocking the receiving member from accepting a pump lever by its physical presence e.g. in receiving member, blocking entry of further objects such as the pump lever.

The cover is shaped to enclose, e.g. by insertion therein at least the receiving member. The cover preferably also covers a portion of the pump axle that protrudes from the casing, if any such protruding portion is present. The cover comprises an opening in a side wall that is arranged to allow inserting the insert into the receiving member while the cover is positioned over the receiving member.

The cover and the insert are arranged to mutually engage when the locking mechanism is in the locked condition. When engaged, removal of the insert from the receiving member and removal of the cover from the receiving member is simultaneously prevented. Mutually arranged to engage may be understood to pertain to means known within the field of locks. For example, the lock may be provided with a locking member that is cooperatively connected to the lock and arranged to latch into a clasp that is provided to the cover operating as closing cup of the lock.

Further, the cover has a continuously sloping side wall to prevent a tool from engaging to the side wall. The side wall providing a continuously sloping exterior surface from a proximal end of the cover whichis at the casing when in use to a distal end of the cover away from the casing with the effect of reducing grip, e.g. of an external gripping means such as a plier, onto the cover. Accordingly, reducing the ability to provide external leverage to the cover and/or to the receiving member enclosed therein so long as the locking mechanism is in place When the hydraulic pump unit is locked by the locking mechanism as disclosed herein the receiving member, e.g. a cavity thereof, 1s blocked and covered by the cover piece altogether preventing unauthorized persons from operating the pump with a lever and shielding the receiving member from unauthorized access, e.g. by external gripping means reducing the possibility to force the receiving member and the hydraulic pump into action.

According to a further aspect the present invention relates to a kit of parts for fitting, e.g. retrofitting, a hydraulic pump unit of a truck with the locking mechanism. The kit comprises the insert and the cover as described herein.

BRIEF DESCRIPTION OF DRAWINGS These and other features, aspects, and advantages of the apparatus, systems and methods of the present disclosure will become better understood from the following description, appended claims, and accompanying drawing wherein: FIGs 1A and B depict aside-view image of a truck with a cabin a normal position and in a tilted position; FIG 2A depicts a truck indicating a position of a hydraulic pump unit and FIG 2B provides a close-up image of a manually operable hydraulic pump unit; FIGs 3A-C depict a hydraulic pump unit with and without locking mechanism in place; FIGs 4A and B depict partial cross-section views of a hydraulic pump unit with a locking mechanism in locked and unlocked condition; FIGs 5A and B depict partial cross-section views of a hydraulic pump unit with a locking mechanism; FIGs 6A and B provide arear and top perspective views of the locking mechanism; FIGs 7A-C illustrate the buildup of an insert; and FIGs 8A-C illustrate top, side, and cross section side views a locking mechanism.

DESCRIPTION OF EMBODIMENTS Terminology used for describing particular embodiments is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless 5 the context clearly indicates otherwise. The term "and/or" includes any and all combinations of one or more of the associated listed items. It will be understood that the terms "comprises" and/or "comprising" specify the presence of stated features but do not preclude the presence or addition of one or more other features. Likewise it will be understood that when a connection between structures or components is described, this connection may be established directly or through intermediate structures or components unless specified otherwise. The invention is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. In the drawings, the absolute and relative sizes of systems, components, layers, and regions may be exaggerated for clarity. Embodiments may be described with reference to schematic and/or cross- section illustrations of possibly idealized embodiments and intermediate structures of the invention. In the description and drawings, like numbers refer to like elements throughout. Relative terms as well as derivatives thereof should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the system be constructed or operated in a particular orientation unless stated otherwise.

FIG 1A provides a schematic side view images of a truck 100 that is provided with a conventional hydraulic pump unit 1. The cab in of the truck in FIG 1A is in a normal, untilted position. Upon activating the hydraulic pump unit 1 hydraulic cab-tilting mechanism 2 tilts the cab to a tilted position. In FIG 1B the cab is depicted in a service position wherein the cab is fully tilted to provide access to parts of the truck below the cab, e.g. the engine compartment (not marked). It will be understood that the hydraulic pump unit can also be activated to only partially tilt the cab (not shown). While a partially tilted position may not give complete access to the engine compartment, a truck with a partially tilted cab will, for safety reasons, be unable to drive to a different location. FIG 2A provides a partial view of a truck indicating a position of the hydraulic pump unit 1 and the hydraulic cab-tilting mechanism 2 relative to the cabin. The hydraulic cab-tilting mechanism 2 is connected to the pump via tubing (shown but not marked). The hydraulic pump unit 1 can be operated manually, e.g. by an operator standing on a position next to the truck. Typically, as shown in more detail in FIG 2B, the hydraulic pump unit 1 comprises a casing 3 comprising a hydraulic pump. The hydraulic pump may be activated manually, without opening the casing, by a lever 5 operating on a receiving member 6 that 1s connected to the hydraulic pump. Typically, the pump can be activated by providing a reciprocal pumping motion, e.g. as schematically illustrated in FIG 2B depicting alever 5 moved between a first extreme position a second extreme position (dashed line, marked 5). The lever may be permanently attached to the receiving member

6. Typically, the lever is detachable and may be stowed separately only to be used when tilting is desired when the lever can be inserted in a cavity 6c of the receiving member 6 (see e.g. FIG 3A). The lever may take any suitable shape or form e.g., arod or bar, dimensioned to fit into the receiving member. As the receiving member 6 is typically exposed, e.g. outside the casing 3, unauthorized access to the receiving member 6 can occur which can result in unauthorized operation of the pump and of the hydraulic cab- tilting mechanism associated therewith. It will be understood that unauthorized operation of the pump may be performed with a tool, e.g. plier or wrench means fitting into or gripping onto the receiving member of a reference hydraulic pump unit and that prevention of unauthorized pump operation is highly desirable.

FIG 3A provides a more detailed view of a conventional hydraulic pump unit 1’, i.e. without locking mechanism. Indicated in the figure is a casing 3 housing at least the hydraulic pump (not visible). Shown in the figure are three connectors 4t protruding from the housing for connecting electric control wiring and/or for tubing connecting the hydraulic pump to the hydraulic cab-tilting mechanism 2. Also protruding from the housing (in the embodiment as shown from a front face 3f of the housing) is a portion of the pump axle 8. On one end, the pump axle is connected to the hydraulic pump. Driving the pump axle, e.g. by imposing a reciprocal pumping movement, allows manual operation of the hydraulic pump. Connected to pump axle is a receiving member 6. The receiving member is arranged to detachably receive alever, e.g. a pump lever. Typically the receiving member 6 includes a cavity 6¢ or hole, extending through the receiving member 6 (see e.g. FIG 4A for a cross section view of the receiving member). In the embodiment as shown the cavity has an essentially circular perimeter, allowing insertion of around (cylindrical) lever, e.g. a rod. The invention is not to be construed as to be limited to receiving members having cavities as depicted.

FIGs 3B-C depict perspective views of the hydraulic pump unit 1 that is in accordance with the invention accompanied with the locking mechanism 20 comprising the insert 21 and cover 22 as described herein. Fig 3C illustrates the hydraulic pump unit with the locking mechanism 20 in place, FIG 3B illustrates the unit during installation of the locking mechanism 20, whereby the cover 22 is already placed over the receiving member 6 and the part of the pump axle 8 that protrudes from the casing 3. Insertion of the insert is schematically represented by a dashed arrow. View of the axles and receiving member 6 is obstructed by the cover 22. The cover 22 comprises an opening 27 in its sidewall 22s. The opening matches the cavity 6¢ of the receiving member 6 such that the insert 21 can be inserted in the cavity while the cover is in place. Matching the opening 27 of the cover to cavity of the receiving member can be understood to relate to at least one of, preferably all, of matching the size, shape, and the relative position of opening to the size, position, and shape of the cavity of the receiving member 6.

As shown, the cover 22 is preferably shaped to enclose a volume matching an outside geometry of the receiving member. As such, the cover may be understood to be arranged to cover, i.e. prevent external access to, the receiving member 6 and a part of the pump axle protruding from the casing 3. Preferably, the cover 22 is dimensioned to cover said parts from a proximal end at the casing 3 (adjacent to the cover 22) to a distal end away from the casing. Preferably, the proximal end (22p, see FIG 5B) is shaped to match a surface of the casing, e.g., the front face 3f, such as to abut the casing when in place. Preferably, the cover has a continuously sloping side wall 22s from the proximal end of the cover to the distal end of the cover as to provide a continuously sloping outer surface. The sloping side wall has the benefit to reduce grip of an external gripping means onto the cover 22, reducing the ability to provide external leverage to the cover and to the receiving member enclosed therein while the locking mechanism with cover remains in place. Preferably, the angle a between the sloping sidewall 22s and a normal (‘7’), see FIG 3C and 5B) to the proximal end 22p of the cover (which in use faces the casing 3, e.g. front surface 3f of the casing) isin a range between 15 and 60 degrees or more, so that a tool cannot effectively engage on its sloping sidewall surface. The smaller the angle the higher the likelihood an external tool, e.g. a wrench, can get a firm grip onto side wall 22s. The higher the angle the more difficult it will be to force the cover with an external gripping means. Higher angles, e.g. above 60 degrees can effectively reduce grip but may be less preferable due to increased overall dimensions (base width) of the cover. Preferably, the angle a is in a range between 15 and 45 degrees.

An angle in said range, e.g. 20 degrees or 30 degrees was found to provide a good balance in providing tampering protection while maintaining an acceptable overall dimension of the cover.

Preferably, the side wall 22s has a continuous smooth outside perimeter providing a continuous smooth outer surface finish that is essentially without protrusions, e.g. ridges, grooves or corners, which could provide providing grip to an external tampering or gripping tool.

Preferably, the outside perimeter closely follows a reference circle (see e.g.

FIG 8). Preferably the cover 22 has an overall conical geometry or a geometry resembling a truncated cone, e.g. as shown in FIG3C and 5B.

The insert 21 comprises a key-operable lock 26 (see FIG 4A) to switch the locking mechanism 20 between a locked and unlocked condition.. As shown in FIGs 3B and C the lock with inserted key 23 is in an unlocked condition.

The insert is dimensioned (shaped) to be reversibly insertable into the receiving member 6 when the locking mechanism 20 isin an unlocked condition and to block the receiving member from receiving a pump lever while the insert 6 is inserted therein.

As is illustrated in more detail in FIGs 4A and B the cover 22 and the insert 21 are arranged to mutually engage in the locked condition.

This prevents removing the insert from the receiving member 6 and prevents removal of the cover 22 from the receiving member so long as the locking mechanism is in the locked condition.

In a unlocked condition the insert and cover may be removed from the receiving member 6. Accordingly, the unlocked and the locked condition respectively allow and disallow operation of the hydraulic pump e.g. via a pump lever.

FIGs 4A-B depict cross section side views of the hydraulic pump unit 1 in a direction along the length of the insert 21 and through the cavity of the receiving member 6. In FIG 4A the locking mechanism 20 1s depicted in a locked condition.

In FIG 4B the mechanism is depicted in an unlocked condition.

Form an outside position the condition may not be directly visible.

In the embodiment as shown the condition of the locking mechanism 20 can be assessed from a relative orientation of the opening for the key 21k. Arranged to mutually engage in the locked condition may be understood to pertain to any suitable means known within the field of locks. For example, in some embodiments the lock may be provided with alocking member 28 which is cooperatively connected to the lock and arranged to latch into a clasp 29 provided by the cover 22 serving as closing cup of the lock. The lock itself may comprise standard marketed lock including a cylinder 26, s sleeve carrier, e.g. a plastic sleeve carrier, and a slot bus, which can be secured to the carrier by local melting. For details reference is made to FIG 7. The key can advantageously be the same as the motor ignition key.

The insert and/or the cover are preferably dimensioned to have a length such that a terminal surface of the insert 21s lines up with the sidewall of the cover when the locking mechanism is in a locked condition.

Preferably, the insert lines up with the sidewall of the cover within 5 millimeter or less, e.g. within 1 millimeter. Preferably, the insert does not protrude from the cover when inserted. That is the terminal surface 21s is preferably level or slightly recessed with respect to the cover sidewall. The better the insert and cover line up the harder tampering with the lock 26 and or the locking mechanism 20 as a whole will be. As mentioned in relation to FIG 3B, the opening 27 in the sidewall 22s of the cover preferably matches an outer dimension of the insert 21 such a to provide a minimal annulus between the cover and the insert. Thus reducing a dimension of an engagement point for an external tool, e.g. a tampering device. Preferably, the annulus or separation between the insert and the cover sidewall is no larger than 1 millimeter. Preferably, the separation is less, e.g. below 0.5 mm (half a millimeter) or less, e.g. less than 0.2 mm, e.g. 0.1 mm. The smaller the separation between the insert and the sidewall opening the harder tampering with the locking mechanism 20 will be.

FIG 5A illustrates a partial cross section view of the hydraulic pump unit 1 in a direction along the pump axle 8 and along the length of the insert 21 and the lock 26. As shown, the cover 22 encloses the receiving member 6 and the portion of the pump axle 8 protruding out of the casing 3. An insert 21 is inserted in receiving member 6. Terminal ends of the cover and the insert 21s line up. FIG 5B illustrates a partial cross section view of the hydraulic pump unit in a direction along the pump axle 8 and across the receiving member 6 and insert 21. As shown, proximal ends of the cover 22p line up with (abut) the front face 3f of the casing 3.

In some preferred embodiments, one of the casing 3 and the cover 22 is provided aprotrusion 30 and the other of the casing and the coveris provided with a recess 31 matching the protrusion to, when engaged, prevent rotation of the cover 22 relative to the casing 3. Preventing rotation of the cover 22 relative to the casing 3 prevents actuation (driving) of the receiving member and of the pump axle 8 connected thereto, further mitigating unauthorized operation of the hydraulic pump unit 1. In a preferred embodiment, e.g. as shown, the protrusion 30 is provided by a screw on the casing having a raised head, that is raised above a level of an exterior casing surface 3f. Advantageously the screw may be already present on the casing, e.g. to fix internal components. Alternatively, or in addition protrusions may be purposefully added to the housing. It will be understood that the protrusion 30 is not to be construed as to be limited to screws or any other fixing means such as nuts or bolts having a portion raised above a surface of the casing. The protrusion, e.g. the length of the screw head has a length suitable to match the recess 31. Preferably, the protrusion has a length of at least 3 millimeter or more, e.g. in a range between 5 and 15 millimeters, such as 1 centimeter. In some embodiments the hydraulic pump unit 1 comprises a plurality of distributed protrusions and recesses for further protection from rotating (forcing) the receiving member 6 when the coverisin place. In one embodiment, e.g. as shown in FIGs 5B and 6A,

the cover comprises first and second recess 31. The second recess is positioned to match a further protrusion, e.g. raised screw head, or a protrusion on the casing 3 of a hydraulic pump unit 1 which is mounted on a truck in a mirrored position (e.g. on the left side). Accordingly, a single set of insert 21 and cover 22 may be applied to a plurality of differently configured trucks.

FIGs 6A-B illustrate perspective views of embodiments of the locking mechanism 20 comprising insert 21 and cover 22 as described herein. FIG 6A depicts a rear perspective view of the locking mechanism 20 in an unlocked condition wherein the lock member 28 of lock 26 is not engaged with clasp 29. FIG 6B depicts a top perspective view of the locking mechanism 20 in a locked condition, whereby the key is inserted in the lock. According to a second or further aspect of the invention, the insert 21 and cover 22 as described herein may be comprised in, or form, a kit of parts constituting a locking mechanism 20 for use with a hydraulic pump unit of a truck. The kit may be of particular use for retrofitting a hydraulic pump unit with a locking mechanism. Such hydraulic pump unit. e.g., as depicted in FIG 3A, unit comprising a casing enclosing a hydraulic pump that can be manually operated with a pump lever that is detachably receivable in a receiving member (or a cavity therein) wherein the receiving member 6 is located outside the casing and connected to the pump via a pump axle which is protruding through the casing. The insert 21 and the cover 22 can advantageously include one or more of the features described herein in relation to the hydraulic pump unit 1 according to the invention to retro-fit hydraulic pump units without locking mechanism with the same benefits.

In some preferred embodiments, e.g. as shown in FIG 6A, the cover 22 and the insert 21, e.g. the sleeve carrier of the lock, are provided with matching guiding ridge 32 and groove 33 members. Provision of matching guiding ridge 32 and groove 33 members allows sliding the insert 21 into the cover, e.g. a cover placed over a receiving member 6, while preventing rotational movement of the insert 21 relative to the cover 22 and/or relative to the receiving member enclosed thereby. FIGs 7A-C respectively elucidate the buildup of an embodiment of the insert 21 comprising: a conventional cylinder lock 26 that is purposefully provided with lock member 28; a slot bus 26b; a circhp 26c; and sleeve member 26s with groove members 32.

Preferably, the cover 22 is an single injection molded or die casted element. Compared to a cover formed by a plurality of joined parts, a single molded or casted cover advantageously comprises less ridges and/or grooves which may potentially serve as engagement points for tampering tools. It is noted that the lines e.g. as depicted in the cover of FIG 6B are not intended to mark boundaries between joined parts (grooves) but serves as guide to the eye highlighting a preferred overall truncated cone shape of the locking mechanism 20. In some embodiments, the cover comprises, or is essentially formed of, a metal or an alloy including but not limited to aluminum and cast iron. Cast iron having the benefit of a comparatively high toughness and surface hardness resisting grip due to surface deformations caused by tampering tools, e.g. a plier with hardened teeth. Alternatively, or in addition, the cover comprises, or is essentially formed of, a tough plastic composition including but not limited to PVC and reinforced plastic compositions. In a preferred embodiment, the cover 22 is formed of a composition having a fracture toughness Kic (as determined by ASTM E399) in excess of 10 MPa.m 2, preferably in excess of 20 MPa.m 12, e.g. in a range between 20 and 90 MPa.m 2. The higher the toughness, the higher the resistance to fracturing or cracking. Suitable compositions include but are not limited to aluminum and cast iron. Aluminum typically has a Kicin a range between 10 and 40 MPa.m.!?. Cast iron (e.g., GGG40-type nodular cast iron) typically has a Kic in a range between 20 and 80 MPa.m 12, Forming the cover of a tough composition can reduce a likelihood of circumventing the locking mechanism 20 by applying blunt force, e.g. shock,

to damage, e.g. crack the cover 20. Alternatively, or in addition, a material's toughness can be expressed as a fraction of In another or further preferred embodiment, the cover 22 comprises a hardened exterior coating having a HRC hardness on the Rockwell scale (as determined by ISO 6508-1) in excess of 50, e.g. between 50-60 or more e.g. between 50 and 70. The higher the hardness the higher the resistance to scratching or indentation.

Provision of a hardened exterior coating can advantageously reduce a likelihood of circumventing the locking mechanism 20 as the hardened exterior reduces grip to the cover due to surface deformations caused by tampering tools, e.g. pliers or wrenches, in particular in combination with a continuously sloping side wall 22s as described herein.

It will be appreciated that covers with a side wall 22s at a given slope (angle a, e.g. 20 degrees) having a comparatively hard coating will be more tamper resistant than covers of which the side wall has a similar slope but with a comparatively softer exterior surface.

Reference is made to FIG 8 that depicts top (FIG 8A), side (FIG 8B), and cross section side views (FIG 8C) of a locking mechanism comprising an insert 21 and a cover 22. For covers with a hard exterior surface (e.g. coating) having a hardness in excess of 50 HRC or more, preferably in excess of 55, a comparatively less inward tapering overall 20 geometry may be acceptable (i.e. smaller angle a, e.g. in a range between 15 and 25 degrees). Conversely, for covers with a softer external surface (coating), e.g. below 50HRC, such as polymers larger angles may be preferred, e.g. in a range between 25 and 45 degrees.

Accordingly, as depicted in FIG 8A-C, for a given height (e.g. 36 millimeter), which can be determined by a dimension of the receiving member, covers with a hard exterior surface can advantageously have a comparatively small base, e.g. 72 millimeter.

In some preferred embodiments, an external surface of the cover 22 1s provided with a signal color, e.g., red or yellow, to deter unauthorized persons from tampering with the hydraulic pump unit 1.

For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

For example, while embodiments were shown for a hydraulic pump unit 1 including a locking mechanism 20, also alternative ways such as a kit of parts including the insert 21 and the cover 22 as described herein are explicitly be envisaged and may be applied to hydraulic pump unit of trucks without such locking mechanism for achieving a similar function and result.

The various elements of the embodiments as discussed and shown offer certain advantages, such as preventing unauthorized operation of the hydraulic cab-tilting mechanism by blocking access to the receiving member 6 of a hydraulic pump unit 1 while simultaneously covering the receiving member 6 to prevent forcing hydraulic pump, e.g., via external gripping means.

It is appreciated that this disclosure offers particular advantages including providing cost effective theft and/or vandalism prevention for both precious truck parts as well as cargo hauled by a truck.

In interpreting the appended claims, it should be understood that the word "comprising" does not exclude the presence of other elements or acts than those listed in a given claim; the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements; any reference signs in the claims do not limit their scope; several "me ans" may be represented by the same or different item(s) or implemented structure or function; any of the disclosed devices or portions thereof may be combined together or separated into further portions unless specifically stated otherwise.

Where one claim refers to another claim, this may indicate synergetic advantage achieved by the combination of their respective features.

But the mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot also be used to advantage.

The present embodiments may thus include all working combinations of the claims wherein each claim can in principle refer to any preceding claim unless clearly excluded by context.

Claims (11)

Conclusions A hydraulic pump unit (1) for feeding a hydraulic cab tilt mechanism (2) of a truck (100), the hydraulic pump unit (1) including a housing (3) enclosing a hydraulic pump (4), which can be operated manually be connected to the pump with a pump handle (5) removably receivable in a receiving element (6) located outside the housing and connected to the pump via a pump shaft (8) extending through the housing, in which the receiving element is equipped with a locking mechanism ( 20) offering a locked or unlocked condition, the locking mechanism (20) comprising: - an insert (21) including a key operated lock (26), the insert being dimensioned to be reversibly insertable into the receiving element (6) when the locking mechanism (20) is in an unlocked state and to block the receiving member from receiving the pump handle while the insert (21) is inserted therein, and; - a cover (22) shaped to enclose the receiving element (6) and a portion of the pump shaft (8) protruding from the housing (3), the cover being shaped to allow the insert (21) to the receiving element (6) can be inserted; wherein the cover and the insert mutually interlock in the locked state, to prevent the insert from being removed from the take-up element (6) and to prevent the cover (22) from being removed from the take-up element, and wherein the cover ( 22) includes a continuous sloped sidewall (22s) from a proximal end of the cover (22) at the housing (3) to a distal end of the cover remote from the housing (3) to prevent tool engagement on the side wall. The hydraulic pump unit (1) according to claim 1, wherein one of the housing (3) or the cover (22) is provided with a protrusion (30) and the other of the housing or the cover is provided with a recess which corresponds to the projection to prevent rotation of the cover and the receptacle contained therein relative to the housing when interlocked. The hydraulic pump unit (1) according to claim 1 or 2, wherein the projection is provided by a screw on the housing with a raised head. The hydraulic pump unit (1) according to any preceding claim, wherein the cover (22) and the insert (21) are provided with mating guide cam (32) and groove members (33) to engage the insert (21) in the receiving member (6 ) to slide. The hydraulic pump unit (1) according to claim 2, wherein the cover (22) includes a first and second recess positioned to correspond to a first and second projection on the housing. The hydraulic pump unit (1) according to any preceding claim, wherein the cover (22) is an injection molded or molded element. The hydraulic pump unit (1) according to any preceding claim, wherein the cover (22) is formed of a composition having a fracture toughness Kic of more than 10 MPa·m··*2. The hydraulic pump unit (1) according to any preceding claim, wherein the cover (22) includes a hardened outer surface coating having an HRC hardness on the Rockwell scale of greater than 50. The hydraulic pump unit (1) according to claim 8, wherein an angle (go) between the continuously sloping side wall (22s) of the cover (22) and a normal to the proximal end (22p) of the cover is between 15 and 45 degrees. The hydraulic pump unit (1) according to any preceding claim, wherein an outer surface of the cover (22) is provided with a signal color. A kit of parts including the insert (21) and the cover (22) according to any preceding claim for retrofitting a hydraulic pump unit of a truck with a locking mechanism.