Pallet truck for transporting goods

Pallet truck for transporting goods that has a substantially horizontal frame on which the goods to be transported are placed. In one implementation the horizontal frame includes two substantially parallel arms with each arm having two parallel longitudinal extensions that define a space between them. Each of the two parallel longitudinal extensions has a wall that face each other and which are visible and accessible through the space. The longitudinal extensions being visible and accessible from above for their cleaning.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to and claims the benefit and priority to European Patent Application No. EP10382261, filed Sep. 30, 2010.

TECHNICAL FIELD

This invention relates to pallet trucks for transporting goods, and in particular to pallet trucks for transporting goods to be used in clean environments and spaces, such as clean rooms, food production rooms and laboratories in the chemical sector.

BACKGROUND

Clean environments or spaces, such as clean rooms, food production rooms or laboratories in the chemical sector, are spaces in which materials and/or objects and goods that are sensitive to contaminants and other substances associated with dirt, such as pharmaceutical or food products, are handled. These types of products are generated from a raw material that is introduced into or removed from clean spaces and/or handled in the clean spaces by means of handling apparatuses such as high-lifting pallet trucks.

Pallet trucks comprise a frame that generally comprises two parallel longitudinal arms, and there are known pallet trucks in which the frames are lifted mechanically (manual mode), and in which the frames are lifted electrically by means of motors (automatic mode). In both cases contaminating substances may adhere to the pallet truck, and/or the pallet truck itself may generate contaminating substances that adhere to its elements, which may be harmful for the clean room and/or for the goods handled.

U.S. Publication US2003/0080544A discloses a solution to the aforementioned drawbacks. The application discloses a pallet truck that is covered with at least one protective covering, and the covering may correspond with a single unit, the entire covering being capable of being replaced by a new one when it is deemed that said covering contains dirt and/or contaminants that may be harmful, or it may correspond with a plurality of units that are joined together to cover different elements of the pallet truck, so that when it is deemed that part of said covering contains dirt and/or contaminants it is not necessary to replace the entire covering, it being sufficient to replace said element only.

SUMMARY OF THE DISCLOSURE

It is an object of this invention to provide a pallet truck for transporting goods adapted for its use in clean environments and spaces, such as a clean room.

The pallet truck of the invention is used to transport and/or handle goods. Said pallet truck comprises a frame on which are disposed the goods to be transported and which comprises two substantially parallel and longitudinal arms.

Each arm comprises two parallel longitudinal extensions that define a space between them, comprising two walls that face each other and which are visible and accessible through said space, said longitudinal extensions being visible and accessible from above for cleaning.

As a result the arms may be cleaned from the outside in a simple manner and without the risk of leaving areas uncleaned. In addition, as all the areas are visible and accessible from above, the risk of dirt accumulating in areas that are difficult to access or in areas that cannot be inspected visually is reduced, largely preventing areas from remaining unclean. With the pallet truck of the invention it is not necessary for additional elements to be disposed, such as canvases or coverings, to cover the frame and prevent it from becoming dirty, and which would then have to be replaced by new ones when they become dirty.

These and other advantages and characteristics of the invention will be made evident in the light of the drawings and the detailed description thereof.

DETAILED DESCRIPTION

The figures show different embodiments of the pallet truck100for transporting and/or handling goods of the invention. In a first embodiment, shown inFIGS. 1 to 6, the pallet truck100corresponds with a manual conventional pallet truck. In a second embodiment, shown inFIG. 7, the pallet truck100corresponds with a manual scissor-type pallet truck. In a third embodiment, shown inFIGS. 8 and 9, the pallet truck100corresponds with an electric pallet truck.

The pallet truck100, in any of its embodiments, comprises a substantially horizontal frame1on which the goods to be transported and/or handled are placed, and which comprises two substantially parallel and longitudinal arms10and11, articulation means connected to the frame1and adapted to cause a lifting of said frame1from a rest position Pr to an active position Pa, and action means by means of which a movement of the pallet truck100and the lifting of the frame1are caused. The action means comprise at least one control wheel40that runs along a surface when the pallet truck100moves and which is facing one end of the frame1, and the pallet truck100comprises at least one wheel6disposed approximately on one end of each arm10and11, opposite to the end to which the control wheel40is facing, which allows the movement of said pallet truck100along with the control wheel40. Preferably the control wheel40is bigger than the wheel6, and the pallet truck100can comprise two or more control wheels40and wheels6.

The action means also comprise a control pad41on which a user can act to cause the movement of said pallet truck100and/or the lifting of the frame1, and transmission means42to transmit to the control wheel40the movement of the pallet truck100and to the articulation means the passage of the frame1from the rest position Pr to the active position Pa and vice versa, caused by the user on the control pad41. In the first embodiment and the second embodiment, the transmission means42is disposed on the control wheel40, and comprises a base420to which said control wheel40is joined with freedom of movement, the frame1also being connected to said base420, as shown inFIG. 3for example. In said two embodiments, said transmission means42also comprises a hydraulic cylinder421or an equivalent means for causing the lifting of said frame1, which are fixed on said base420. Said transmission means42and its arrangement are not the object of the invention, as a result of which its operation and arrangement are not explained, these being conventional. In the third embodiment, the transmission means42comprise electrical action means M, for example a motor, instead of a hydraulic cylinder421, which is preferably disposed on the wheel40, as it will be explained below.

The two arms10and11are analogous, as a result of which only one of them is explained, it being evident that both the explanation and the terminology apply to the other arm11.

With reference toFIG. 4, for example, the arm10comprises two longitudinal extensions101and102that define a space12between them, comprising two walls103and104that face each other through said space12, which are visible and accessible from above for their cleaning through said space12, said longitudinal extensions101and102thus being visible and accessible from above for their cleaning, and preferably comprising a substantially rectangular section. The arms10and11can thus be cleaned from above in a simple manner, reducing to a great extent the risk of leaving areas uncleaned. In addition, as the longitudinal extensions101and102are visible and accessible from above, there is a reduced risk of dirt accumulating in areas of said longitudinal extensions101and102, and, therefore, said frame1, which is difficult to access, or in areas that cannot be inspected visually, preventing to a large extent areas from being left uncleaned. With the pallet truck100of the invention it is not necessary to dispose additional elements, such as canvases or coverings, to cover the frame1and prevent it from becoming dirty, which would then have to be replaced by new ones when they become dirty and/or contaminated.

The arm10preferably comprises a curved section on one of its ends, opposite to the one facing the control wheel40. The longitudinal extensions101and102can thus be two different elements that are connected at the curved end by means of continuous welding for example, or may be constituted by a single element (a plate for example), which is bent until it takes a substantially U-shaped form, each extension of the U corresponding with one of the longitudinal extensions101and102. Said longitudinal extensions101and102are substantially rectangular.

Preferably, the arm10comprises a plurality of sheets5, which are preferably transversal, which connect the two corresponding longitudinal extensions101and102to each other and thus provide greater rigidity to the arm10. Said transverse sheets5are also visible and accessible from the outside, so that they can be cleaned easily and effectively without the need to turn the pallet truck100around, for example.

The wheel6is disposed approximately on one end of the arm10, connected on each side to a longitudinal extension101and102of said arm10with freedom of rotation, said wheel6being disposed in the space12defined by the two longitudinal extensions101and102of the corresponding arm10and11when the pallet truck100is in the rest position Pr. The articulation means are attached to the wheel6and are visible and accessible from above for their cleaning, so that when the frame1moves to the active position Pa, said wheel6remains in its position in contact with the surface along which it runs when the pallet truck100moves, said pallet truck100being capable of moving if required. Additionally, when, with the frame1in the rest position Pr, the pallet truck100moves, thanks to the space12, the noise caused by the rubbing of the wheels6against the floor when they move spreads through said open space12without surrounding any structure or zone of the frame1, which acts as a sounding box, as a result of which the pallet truck100of the invention generates less noise than the pallet trucks100known in the prior art. Similarly, the noise caused by the banging and vibrations transmitted to the frame1by the wheels6when they move on the floor is also absorbed by polymer bearings4comprised in the pallet truck100.

The articulation means, shown for example inFIG. 5, comprise, for each arm10and11, a transverse support shaft30that is visible and accessible from above for its cleaning and which is disposed between the two longitudinal extensions101and102of the arm10, connected at its ends to said longitudinal extensions101and102, and a lever31that is connected to said support shaft30and to the base420of the action means and which rotates in relation to said base420when the frame1is lifted up. The lever31is visible and accessible from above for its cleaning, and is disposed at at least one preset minimum distance Dmin in relation to the closest longitudinal extension101and102. Preferably the lever31is connected to the support shaft30in the proximities of one end of said support shaft30, close to a longitudinal extension101and102but always maintaining at least the preset minimum distance Dmin in relation to said longitudinal extension101and102, which is approximately 6 millimeters. This thus ensures a minimum space of approximately 6 millimeters between two elements (lever31and longitudinal extension101and102, in this case), thereby restricting the accumulation of dirt between said two elements, and thus making it easier to clean the frame1of the pallet truck100. Some of the polymer bearings4, which dampen the noise of the pallet truck100, are also used as spacers to achieve the minimum distance Dmin.

The articulation means also comprise, for each arm10and11, an additional transverse support shaft34that is visible and accessible for its cleaning and which is disposed between the two longitudinal extensions101and102of the arm10, connected at both ends to said longitudinal extensions101and102, a longitudinal sheet32that extends between the two longitudinal extensions101and102from said additional support shaft34and which is connected to the wheel6, and a rotating plate33on each side of the wheel6, which is connected with freedom of rotation at one end to said longitudinal sheet32and at the other end to said wheel6, said longitudinal sheet32thus being connected to said wheel6. Each rotating plate33is disposed at at least the preset minimum distance Dmin in relation to the closest longitudinal extension101and102, as shown, for example, inFIG. 6, each side of said longitudinal sheet32being separated from the closest longitudinal extension101and102also by at least said minimum distance Dmin, which is approximately 6 millimeters. This thus ensures a minimum space of 6 millimeters between two elements (rotating plate33and longitudinal extension101and102; and longitudinal sheet32and longitudinal extension101and102, in this case), thereby restricting the accumulation of dirt between said two elements, thus making it easier to clean the frame1of the pallet truck100. Both the rotating plates33and the longitudinal sheet32are visible and accessible from above for their cleaning, thanks to the space12defined between the longitudinal extensions101and102, thereby making them easier to clean. Some of the polymer bearings4, which dampen the noise of the pallet truck100, are also used as spacers to achieve the minimum distance Dmin.

The support shaft30and the additional support shaft34are substantially cylindrical, and are connected to the corresponding longitudinal extensions101and102by means of continuous welding. Preferably said shafts30and34also pass through the longitudinal extension101and102to which they are connected, being connected by both faces to said longitudinal extension101and102. As a result, by means of said continuous welding, the generation of unevenness on the surface of the welding is eliminated or reduced to a large extent, thereby eliminating or reducing to a large extent the risk of dirt accumulating on said welding, thus making it easier to clean the frame1of the pallet truck100.

When the movement of the frame1to the active position Pa is caused, the hydraulic cylinder421(or the electrical action means M) of the transmission means42cause the longitudinal extensions101and102to be lifted up. The lever31thus rotates in relation to the base420, thereby causing the lifting of the longitudinal sheet32, which in turn causes the rotating plate33to rotate in relation to the end connected to the wheel6. Both the frame1and said longitudinal sheet32are thus lifted up, while said wheel6remains in contact with the floor or with the surface along which it runs when the pallet truck100moves.

In the second embodiment of the pallet truck100of the invention the articulation means operates differently, as can be deduced fromFIG. 7, although its operations are not detailed as they are known in the prior art. Instead of a longitudinal sheet32, in said second embodiment of the pallet truck100the articulation means comprise two longitudinal sheets32which are lifted in the manner of scissors (hence the name) in relation to a common shaft39, when the hydraulic cylinder421of the transmission means42causes the longitudinal extensions101and102to be lifted. One of the longitudinal sheets32is connected at one end to the wheel6and at the other end to the corresponding arm10and11, while the other longitudinal sheet32is connected at one end to the base420and at the other end to the corresponding arm10and11. In said second embodiment shown inFIG. 7, a sealed compartment is also shown and in which electrical means (motor, battery, etc) are housed to control the pallet truck100remotely by means of radio-frequency for example, which is usually advantageous in improving efficiency as it reduces the movements of the operator between the loading/unloading position and the control pad41. Said sealed compartment is covered by a cover500that is accessible from the outside, said cover500being capable of being cleaned easily. As it is sealed, no dirt and/or corrosive or contaminating materials may be introduced into said sealed compartment.

The pallet truck100also comprises at least one lug9connected to each rotating plate33, which is fixed to the corresponding longitudinal extension101and102, extending transversally in the space12defined between both longitudinal extensions101and102, said lug9preventing the corresponding rotating plate33from a vertical movement when the pallet truck is moved with the frame1in the rest position Pr. As a result, if, with the frame1in said rest position Pr, the movement of the pallet truck100is caused due to the fact that the rotating plate33cannot move vertically, the possible vibrations of said rotating plate33caused by said movement can be prevented, at least to a large extent, thereby preventing, at least to a large extent, the generation of noise due to said vibrations and due to the fact that the design of the frame1in the form of an open structure prevents echo, along with the reduction of vibrations/noise that are also reduced by the polymer bearings4, a pallet truck100that is quieter than those known in the prior art is obtained.

In the three embodiments each longitudinal extension101and102is substantially L-shaped, with a substantially horizontal first section101aand102aon which are disposed the goods to be transported, and a second section101band102bthat extends substantially perpendicular to said first section101aand102afrom the end of said first section101aand102aopposite to the end on which the wheel6is disposed, the control wheel40and the transmission means42facing the second sections101band102bof the longitudinal extensions101and102, on the side opposite the first sections101aand102aof said longitudinal extensions101and102.

In the three embodiments the two arms10and11are connected to each other by the second sections101band102bof the longitudinal extensions101and102, by means of connecting means that are visible and accessible for their cleaning. Said connecting means comprise a first transverse connecting shaft21that connects a longitudinal extension101and102of an arm10and11with a longitudinal extension101and102facing the other arm10and11, approximately at the point of connection between the first section101aand102aand the second section101band102bof said longitudinal extensions101and102, and which is connected to said two longitudinal extensions101and102, and a second transverse connecting shaft22that connects all the longitudinal extensions101and102of the two arms10and11to each other, approximately on the end of the second section101band102bopposite said point of connection between the first section101aand102aand said second section101band102bof the longitudinal extensions101and102, and which is connected to all the longitudinal extensions101and102. Said connecting shafts21and22are visible and accessible from above for their cleaning, thus making it easier to clean the frame1of the pallet truck100, and are substantially cylindrical or tube-shaped and pass through the longitudinal extension101and102to which they are connected, being connected to both sides of said longitudinal extension101and102by means of continuous welding. As a result, by means of said welding the generation of unevenness on the surface of the welding is eliminated or reduced to a large extent, thereby eliminating or reducing to a large extent the risk of dirt accumulating on said welding, thus making it easier to clean the frame1of the pallet truck100.

The second sections102bof the facing longitudinal extensions102of the two arms10and11comprise a greater length than the second section101bof the two remaining longitudinal extensions101, are passed through by the second connecting shaft22, and are connected to each other at their ends opposite to the point of connection with the corresponding first sections101aand102aby means of connecting means that are visible and accessible from above for their cleaning, such as a stiffening plate8for example. The transmission means42is connected to the frame1by means of said stiffening plate8. In the second embodiment the second sections101band102bcomprise a greater length than in the first embodiment, for example.

In the third embodiment of the invention shown inFIGS. 8 and 9, the pallet truck100is an electrical pallet truck and comprises electrical action means M for moving the pallet truck100, which comprise a motor, a sealed compartment7where said electrical action means M is housed, which is insulated from the outside by means of a cover70that is visible and accessible from above for its cleaning, and air-conditioning means for heating or cooling the interior of the sealed compartment7and preventing the condensation and/or overheating of said sealed compartment7. The cover70is fixed in a sealed manner to a structure of the pallet truck100, by means of ring seals or gaskets or equivalent and known elements that provide sealed closures. The sealed compartment7is fixed to the frame1on one end of the longitudinal extensions101and102of each arm10and11of said frame1, and is disposed on the control wheel40and on the sides of said control wheel40. Said pallet truck100also comprises first detection means (not shown in the figures) disposed in the interior of the sealed compartment7to detect humidity in said interior, which can be conventional, second detection means (not shown in the figures) disposed in the interior of said sealed compartment7to detect the temperature in said interior, which can be conventional, and electronic control means (not shown in the figures), which can be a micro-controller or a micro-processor for example, which determine the humidity and temperature detected by the detection means in the interior of said sealed compartment7and which act upon the air-conditioning means in accordance with said determined relative humidity and temperature, to heat or cool the interior of the sealed compartment7and prevent condensation and/or overheating inside said sealed compartment7. The air-conditioning means preferably comprise a Peltier cell (not shown in the figures), which comprises a first cell fixed to the cover70inside the sealed compartment7and a second cell fixed to said cover70outside said sealed compartment7. Said cells are connected to the cover70and ensure the sealed compartment7remains sealed, as one cell can be connected to the other without this affecting the seal (for example, the sealed closure is provided by the connection between the cover and the perimeter of the cells, the cells being connected to each other by an internal area in the cells themselves). A description of how a Peltier cell functions is not given as this is already known.

In the third embodiment the control pad41comprises a steering member410connected with freedom of tilting to the sealed compartment7by means of an area of connection73shown inFIGS. 10 and 11, which is covered with a lid732and which is disposed on the cover70of said sealed compartment7, the steering member410comprising a longitudinal hole410afor housing wiring701through to the interior of the area of connection73, which extends partially in the interior of said area of connection73, a shaft of the steering member410and a rotation shaft of said steering member410on the cover70being misaligned in relation to each other by a certain distance in order to reduce further the possibility of liquids entering the sealed compartment7. When the pallet truck100is to be cleaned using cleaning liquids, said liquid runs along the steering member410along with the wiring701, and comes out of the hole410ato the area of connection73. If said area of connection73did not exist, there would be a high risk of said liquid entering the sealed compartment7through the wiring701, so that the sealed nature of said sealed compartment7would be reduced, making it a possible source of contamination, in addition to the fact that said entry of liquids would affect the electrical action means M of the pallet truck100. The wiring701must reach the electrical action means M, which requires that it has to be introduced into the sealed compartment7. To enable this the cover70comprises a sealed through-hole700through which said wiring701originating from the hole410aof the steering member410is introduced into said sealed compartment7. The sealed through-hole700is misaligned in relation to the hole410a, so that the liquid originating from said hole410adoes not reach the sealed through-hole700directly, thereby helping to prevent it from entering the sealed compartment7. In addition, the area of connection73comprises a base730disposed on the cover70, which comprises a sealed through-hole aligned with the sealed through-hole700of the cover70of the sealed compartment7, through which the wiring701passes, at least one window731through which the liquid originating from the hole410acan be evacuated, said liquid falling on the cover70, and a slope of at least two degrees to guide said liquid towards said window731and thereby enable it to fall on the cover70, preventing the liquid from reaching the sealed through-hole700. Thus, in addition to the security provided by the sealed nature of said through-hole (obtained by means of ring seals or other known elements), additional security is provided by the fact that it is difficult for a liquid to reach said sealed through-hole700, the sealed nature of the sealed compartment7not being put at risk, and sources of humidity and contamination being prevented. In said third embodiment, the pallet truck100also comprises additional safety devices such as an emergency button, which are connected to the sealed compartment7, for when the electrical action means M needs to be switched off immediately, to cut off the supply to said electrical action means M in this case, said safety devices complying with code IP67 or higher, which are able to withstand cleaning with abrasive agents for example.

In the third embodiment, the pallet truck100of the invention also comprises a safety cover99that is disposed at a maximum preset safety distance in relation to the floor, which is approximately 35 millimeters, thereby complying with the applicable legislation. Said safety cover99covers the rear part of the control wheel40, the part opposing the frame1, and comprises at least one window99aso that said control wheel40can be visible and accessed from the outside for its cleaning. In said third embodiment, the support shaft30, the lever31, the additional support shaft34and the base420are visible and accessible from said window99afor their cleaning. The safety cover99can be fixed, for example, to the structure on which the cover70is disposed, by means of screws or other equivalent and known means.

In the third embodiment, the pallet truck100of the invention can also comprise an additional wheel400on each side of the control wheel40to enable the movement of said pallet truck100, preferably substantially smaller than said control wheel40. Additionally, in said third embodiment the frame1can be equal to that of the first embodiment.