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Title:
LINEN COMPARTMENT AND HOTEL TROLLEY COMPRISING A LINEN COMPARTMENT
Document Type and Number:
WIPO Patent Application WO/2017/209616
Kind Code:
A1
Abstract:
The invention provides a linen compartment for a trolley, the linen compartment comprising a first compartment for clean linen, a second compartment for soiled linen, and a separator separating the first compartment from the second compartment wherein the separator can be moved along a direction inside the linen compartment for adjusting the size of the first and second compartments. By adjusting the size between compartments, and realizing that trolleys in normal use are not simultaneously filled with clean and soiled linen, an efficient use of available space for linen is made. The invention further provides a (hotel)trolley comprising such a linen compartment.

Inventors:
LAMME, Jan (Vaartweg 17, 1394 GL Nederhorst den Berg, 1394 GL, NL)
DEN HOLLANDER, Hendrik Pancras (Ted Visserweg 46, 3951 CE Maarn, 3951 CE, NL)
Application Number:
NL2017/050362
Publication Date:
December 07, 2017
Filing Date:
June 02, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HOTEL FACILITY CONCEPTS IP B.V. (Sweerts de Landasstraat 27, 6814 DA Arnhem, 6814 DA, NL)
International Classes:
B62B3/00; B62B3/02; D06F95/00
Domestic Patent References:
WO2011124769A12011-10-13
WO2011124769A12011-10-13
Foreign References:
US4248442A1981-02-03
US20100283227A12010-11-11
US20160002844A12016-01-07
US20130313029A12013-11-28
DE19841781C12000-02-10
CN204453151U2015-07-08
US5915723A1999-06-29
US4248442A1981-02-03
US20100283227A12010-11-11
US20160002844A12016-01-07
US20130313029A12013-11-28
DE19841781C12000-02-10
CN204453151U2015-07-08
US5915723A1999-06-29
Attorney, Agent or Firm:
NEDERLANDSCH OCTROOIBUREAU (P.O. Box, 2502 LS The Hague, 2502 LS, NL)
Download PDF:
Claims:
Claims

1. A linen compartment (20) for a trolley, the linen compartment comprising

- a first compartment (13) for clean linen;

- a second compartment (14) for soiled linen; and

- a separator (15, 61 ) for separating the first compartment from the second compartment,

wherein the separator can be moved along a direction inside the linen compartment for adjusting the size of the first and second compartment.

2. Linen compartment (20) according to claim 1 , wherein the first and the second compartment (13, 14) have respective first and second enclosures (60, 61), wherein the second enclosure is configured to slide at least partially over the first enclosure or vice versa, thereby reducing the total volume of the linen compartment.

3. Linen compartment (20) according to any one of the preceding claims, wherein the first compartment (13) comprises a shelf (25) which is adapted to adjust to the size of the first compartment. 4. Linen compartment (20) according to claim 3, wherein the shelf (25) and the first compartment (13) are resizable in a number of discrete steps.

5. Linen compartment (20) according to any one of the preceding claims, wherein the second compartment (14) is further divided into sub compartments (41 , 42, 43).

6. Linen compartment (20) according to claim 5, wherein at least one of the further sub compartments (41 , 42, 43) can be closed and reduced in size by vacuum suction or manual compression. 7. Linen compartment (20) according to any one of the preceding claims, comprising an RFID tag reader in at least one of the first compartment and the second compartment, for detecting in-going or out-going linen.

8. Trolley (10) comprising a linen compartment (20) according to any one of the preceding claims.

9. Trolley (10) according to claim 8, further comprising a vacuum pump (1 12) connected to a vacuum hose (31).

10. Trolley (10) according to any one of the preceding claims 8-9 further comprising a supplies compartment (16) above the first compartment (13).

1 1 . Trolley (10) according to any one of the preceding claims 8-10, comprising an electric motor (1 10) for driving wheels (12) of the trolley.

12. Trolley (10) according to any one of the preceding claims 8-1 1 , comprising a wireless communication module (56) for transmitting information about detected ingoing or out-going linen.

Description:
Linen compartment and hotel trolley comprising a linen compartment

Field of the invention [0001] The invention relates to a linen compartment for a trolley for use in hotels. The invention also relates to a trolley, in particular a hotel trolley, comprising such a linen compartment.

Background of the invention

[0002] Hotel trolleys are used by hotel staff for distributing clean linen and hotel room supplies and for collecting soiled linen and waste. The used trolleys usually have a compartment storing clean linen and supplies. Waste and dirty linen are collected elsewhere.

[0003] Current trolleys can only carry a relatively small amount of clean and dirty linen, supplies and waste. As a result, hotel staff must frequently restock the trolley, for example by going to a storage room. These visits to and from the supply room take time away from the time available to the hotel staff to clean and restock the rooms.

[0004] To be able to work more efficiently, and to limit the time spend on restocking the hotel trolley, hotels often use storage rooms at various places in the hotel, for example one on each floor. It is a drawback that these storage rooms take up valuable space which cannot be used for guest accommodations. It is a further drawback that supplying the storage rooms takes time. Finally, it can be difficult to separate clean from soiled linen inside a single trolley. For obvious reasons, the soiled linen cannot be allowed to come in contact with the clean linen.

[0005] US 4,248,442 discloses a laundry cart comprising a plurality of nesting hampers, one atop the other forming a stack of hampers. However, only the top hamper of the stack is accessible for inserting or removing linen. The stack is thus unsuitable for carrying both clean and soiled linen, because then access is needed to two compartments simultaneously.

[0006] WO 201 1/124769 describes a cart with a hamper having a central partition, dividing the hamper in two compartments. The partition can be removed, so that only a single compartment remains. However, when the partition is inserted, the sizes of the two compartments is fixed. In practice, often the clean or the dirty linen compartment will be nearly empty, which is a waste of space. [0007] US 2010 / 283 227 discloses a cart with a single resizable compartment. This does not allow clean and dirty linen to be separated.

[0008] US 2016 / 002 844 describes a laundry basket with a flexible flap which can be used to separate dirty from clean laundry inside the basket. However, the flap can be easily folded the wrong way by accident, so that dirty and clean linen still come in contact with each other. Furthermore, since the flap does not seem to have any structure that can give support, it appears difficult to keep clean linen neatly folded when dirty linen is deposited on the other side of the flexible flap.

[0009] US 2013 / 313 029 discloses a cart with a number of compartments with fixed sizes. In DE 198441781 , a cart is shown which has a number of compartments with a bottom that can be collapsed to form a combined compartment. CN 204453151 also discloses a cart. US 5,915,723 discloses a foldable cart.

[0010] The invention addresses at least one of the above drawbacks of the prior art. Summary of the invention

[0011] According to a first aspect, the invention provides a linen compartment for a hotel trolley, the linen compartment comprising

- a first compartment for clean linen;

- a second compartment for soiled linen; and

- a separator separating the first compartment from the second compartment, wherein the separator can be moved inside the linen compartment for adjusting the size of the first and second compartments.

[0012] The movable separator can be slidably moved. When the separator is moved in one direction, the first compartment size is increased while the second compartment size is simultaneously decreased. When the separator is moved in the opposite direction, the first compartment size is decreased while the second compartment size is increased. The separator may be a flat surface. The separator may have a rectangular shape, and keeps essentially the same shape while it is being moved.

[0013] The movable separator advantageously provides a hygienic separation between clean lined to be distributed to the rooms and soiled linen taken from the rooms. By making the separator movable, it is possible to adjust the space for clean and solid linen. At the beginning of the cleaning round, when the trolley is filled with clean linen and no soiled linen has yet been collected, the space for clean linen is largest, while at the end of the cleaning round the space for soiled linen is made largest. In other words, by adjusting the size between compartments, and realizing that trolleys in normal use are not simultaneously fully filled with both clean and soiled linen, an efficient use of available space for linen is made.

[0014] In this application, the term linen is used for a kinds of washable materials that may be distributed in clean form to hotel rooms and collected in soiled form from said hotel rooms, for example sheets, towels, tablecloths, etc made from linen or a similar material.

[0015] If the trolley according the invention is of sufficient size, it is possible to load the trolley (or at least the linen compartment of the trolley) with clean linen at a washing station, transport the trolley (or linen compartment) to a hotel, do a cleaning round in the hotel, and transport the trolley (or linen compartment) full of soiled linen back to the washing station. No storage rooms for clean and soiled linen are needed in the hotel.

[0016] I n embodiments, the trolley is provided with an electric motor for easier movement. The electric motor can be arranged to start when it detects that a user is pushing the trolley. Use of an electric motor is in particular beneficial if the trolley is of a certain (large) size. This allows linen compartments and trolleys to be made bigger so that they can store enough linen so that frequent trips to a storage room (in the hotel) or washing station (outside the hotel) are not needed. In a further embodiment, the trolley is provided with a mechanism for reducing the size of soiled linen, for example by sucking the air out of airtight bags containing the linen. This advantageously increases the amount of soiled linen that the trolley can carry, further reducing the number of trips to a storage room or washing station.

[0017] In an embodiment, the first and the second compartment have respective first and second enclosures, wherein the second enclosure is configured to slide at least partially over the first enclosure or vice versa, thereby reducing the total volume of the linen compartment.

[0018] I n an embodiment, the first compartment comprises a shelf which is adapted to adjust to the size of the first compartment. In an embodiment the shelf and the first compartment are resizable in a number of discrete steps.

[0019] I n an embodiment, the second compartment is further divided into sub compartments. In an embodiment, at least one of the further sub compartments can be closed and reduced in size by vacuum suction or manual compression.

[0020] In an embodiment, the linen compartment comprises an RFI D tag reader in at least one of the first compartment and the second compartment, for detecting in-going or out-going linen. [0021] The invention further provides a trolley comprising such a linen compartment, for use in hotels. In an embodiment, the trolley comprises a vacuum pump connected to a vacuum hose.

[0022] I n an embodiment, the trolley comprises a supplies compartment above the first compartment. In an embodiment, the trolley comprises an electric motor for driving wheels of the trolley. In an embodiment, the trolley comprises a wireless communication module for transmitting information about detected in-going or outgoing linen.

[0023] Further advantageous aspects are defined in the dependent claims and in the exemplary embodiments.

Brief description of the Figures

[0024] Embodiments of the present invention will be described hereinafter, by way of example only, with reference to the accompanying drawings which are schematic in nature and therefore not necessarily drawn to scale. Furthermore, like reference signs in the drawings relate to like elements.

[0025] In the attached drawings,

• figure 1 schematically shows a hotel trolley according the invention;

· figures 2a-d schematically shows a linen compartment of the hotel trolley;

• figure 3 shows a variant of the linen compartment of the hotel trolley;

• figure 4 shows a further variant of the linen compartment of the hotel trolley;

• figure 5 shows equipment attached to the hotel trolley;

• figures 6a-e show a hotel trolley according a further embodiment of the invention; · figure 7 shows a hotel trolley with an upper compartment according an embodiment of the invention; and

• figure 8 shows a hotel trolley with an external motorized part according an embodiment of the invention. Detailed description

[0026] The following items are shown in the drawings:

10: hotel trolley

1 1 : trolley base

1 10: electric motor

1 1 1 : battery 1 12: vacuum pump 12: wheel

13: clean linen compartment

14: soiled linen compartment 15: movable separation

16: supplies compartment

17: supplies drawer

18: soiled linen opening

19: waste compartment

20: linen compartments

21 : clean linen opening

22: separation rail

23: first shelf part

24: second shelf part

25: shelf

26: first foldable shelf part

27: second foldable shelf part

28: third foldable shelf part

31 : vacuum hose

32: vacuum bag

33: bagged linen

41 : first compacted compartment

42: second compacted compartment

43: uncompacted compartment 44: first compartment separation

45: second compartment separation

46: soiled linen

47: attached vacuum lid

48: vacuum lid

49: vacuum lid cap

51 : first RFID reader

52: second RFID reader

53: third RFID reader

54: weight sensor

55: RFID scanner

56: wireless communication module 60: first module / enclosure

61 : movable partition of first module

62: second module / enclosure

63: upper guide

64: lower guide

65: shelf support

66: airtight enclosure

67: valve

71 : U-shaped support

72: upper module

13': upper clean linen compartment

14': upper soiled linen compartment

73: upper rear door handle

74: upper front compartment flap

75: upper separation

80: detachable engine block

81 : wheel

[0027] Figure 1 schematically shows a cross section of hotel trolley 10 according an embodiment of the invention. The trolley is shown from the side, with the rear of the trolley on the left (where a person might push the trolley forwards, using handle bars not shown in figure 1 ) and the front of the trolley on the right.

[0028] In the trolley base 1 1 , an electric motor 1 10 for driving the wheels 12, a battery 1 1 1 , and a vacuum pump 1 12 are provided. Preferably, the electric motor drive system is arranged so that the motor provides auxiliary power for turning the wheels 12 when the motor drive system detects that a person pushes the trolley in a particular direction.

[0029] Above the base 1 1 the linen compartments are provided: a clean linen compartment 13 and a soiled linen compartment 14 separated by movable separation 15. The separation is necessary for reasons of hygiene. The separation 15 is movable along the length axis of the trolley (indicated by arrows in figure 1 ), so that moving the separation causes a change in the size of the clean and soiled linen compartments 13, 14. In this embodiment, the total size of the clean and soiled compartments remains the same. It is advantageous to start a cleaning round with the separation to the right, so that the clean linen compartment is larger. During the cleaning round clean linen will be distributed and soiled linen will be collected. When more room is needed for soiled linen, the separation 15 may be moved to increase the size of soiled linen compartment 14 and reduce the size of clean linen compartment 13.

[0030] The soiled linen compartment 14 is provided with a used linen opening 18 (e.g. in the form of a flap or a mailbox-like slot). The clean linen compartment 13 also has an opening or door 21 (not shown in figure 1 ) for taking clean linen. A waste compartment 19 is attached to the soiled linen compartment for collecting waste.

[0031] Above the linen compartments 20 a supplies compartment 16 comprising a removable supplies drawer 17 is provided. This compartment 16 is typically used to supply e.g. bathroom articles and the like.

[0032] I n the present embodiment, the clean linen compartment 13 and the supplies compartment 16 are on one side of the trolley (e.g. the rear side which is pushed) and the soiled linen compartment 14 and waste compartment 19 are on the other side (e.g. the front side). While it generally makes sense to keep clean and soiled/used goods separate, this precise distribution is not critical, and variants are possible.

[0033] Figures 2a-d schematically shows a linen compartment 20 of the hotel trolley 10. A guide 22 is provided for the movable separation 15. This guide can be in the form of a rail or a groove which is adapted to receive a protrusion or bearing from the movable separation 15.

[0034] I n figure 2a, in the clean linen compartment 13 a shelf 25 for clean linen is provided. The shelf comprises a first and second shelf part 23, 24 which can slide over each other as the size of the clean linen compartment 13 is reduced by moving separation 15 to the left.

[0035] Figures 2b-c show an alternative shelf 25, comprising three foldable shelf parts 26, 27, 28. In figure 2b, the three foldable shelf parts are horizontally extended, forming the full shelf 25 which can carry three piles of folded linen. In figure 2c, the third shelf part 28 is folded towards second shelf part 27, so that the total shelf is 2/3 of the full shelf length, with remaining two piles of clean linen on it. This fits with a reduced size of the clean linen compartment due to the moved separation 15. In figure 2d, as more soiled linen bags are collected in the soiled linen compartment 14, the three shelf parts 26, 27, 28 are folded on top of each other to further reduce the size of the shelf 25.

[0036] It will be clear to the skilled person that the invention is not limited to the shown shelves. Shelves 25 comprising slidable (figure 2a) or foldable (figures 2b-d) shelf parts using any number of slidable or foldable parts are possible.

[0037] Figure 3 shows a further variant of the linen compartment of the hotel trolley. The linen compartment is provided with a vacuum hose 31 which can be used vacuum seal soiled linen bags 32 before or while they are put in the soiled linen compartment 14. This advantageously reduces the size of the bags 33 of soiled linen considerably. It is well known that soiled, unfolded linen otherwise requires more space than clean, folded linen.

[0038] Figure 4 shows a further variant of the linen compartment of the hotel trolley using a vacuum hose 31 . Instead of using linen bags which can be vacuum sealed, the soiled linen compartment now has sub compartments 41 , 42, 43 separated by separators 44, 45. The sub compartments 41 , 42, 43 can be closed in an airtight fashion with vacuum lids 47, 48. In the present example, sub compartments 41 and 42 have been closed with a lid 47, after which the air is removed from the sub compartments 41 and 42.

[0039] The separators 44, 45 are movable, so that as the air is removed from sub compartment 41 , the separation 44 is moved towards separation 15, so that the total amount of space used by the soiled linen inside sub compartment 41 is reduced. Sub compartment 42 has been similarly reduced in size, by sucking the air out of sub compartment 42 thereby pulling separation 45 closer to separation 44.

[0040] In the present example, sub compartment 43 is still open for receiving soiled linen 46. When it is full, the vacuum lid 48 is placed on top of it and the air is removed from the sealed sub compartment 43. A further partition to the right of sub compartment 43 (not shown) will then be pulled away from the front (right) end of soiled linen compartment 14. The vacuum lid 48 is closed with a removable cap 49.

[0041] In an embodiment not shown in figures 3 and 4, the air is removed from the sub compartments not through suction with vacuum hose 31 but through manual compression of the volume of the sub compartment.

[0042] Figure 5 shows equipment attached to the hotel trolley 10. An RFI D tag reader 51 in the supplies drawer tracks RFI D tags attached to hotel supplies, for stock keeping purposes. The clean linen compartment 13 and soiled linen compartment 14 also have a respective RFI D tag reader 52 and 53, for detecting RFI D tags included in linen. That way, the trolley can automatically keep track of all the outgoing clean linen and the ingoing soiled linen. The supplies drawer may be provided with a weight sensor 54 for determining the weight of remaining supplies.

[0043] The trolley 10 has an attached RFI D scanner for manually scanning RFI D tags. The trolley 10 further has a wireless communications module 56 for transmitting data related to the trolleys inventory (as e.g. determined by one or more of the RFI D tag readers 51 , 52, 53, the scanner 55, or weight sensor 54) to a central processing system (for example operated by the supplier of clean linen). This way, a central system can keep track of the number of linen items distributed in and collected from a hotel.

[0044] Figures 6a-e show a hotel trolley according a further embodiment of the invention. Compared to the embodiment of figure 1 , in figures 6a-e the clean and soiled linen compartments 13 and 14 have respective enclosures in the form of first module 60 and second module 61 , where enclosure / module 62 can slide at least partly over enclosure / module 60. Enclosure 62 is closed on all sides, except the side facing enclosure 60 with separation 61 , so that enclosure 62, being slightly larger than enclosure 60, can slide over enclosure 60. In addition, enclosure 62 has a flap or mailbox-like slot opening for inserting soiled linen into the enclosure. This opening 18 is in the top part of the enclosure 62, but it can also be provided in one of the three sides.

[0045] The separation 61 between clean and soiled compartments in the present example serves as a front side wall of module 60, and is movable inside module 60 using guides 63 and 64 inside module 60. These guides 63, 64 can be formed as grooves or rails or the like, interacting with protrusions or bearings of movable separation 61 .

[0046] It should be noted that the arrangement of figure 6a with the soiled linen compartment 14 enclosure 62 being movable over the clean linen compartment 13 enclosure 60 is but an example. The reverse, enclosure 60 movable over enclosure 62 is also possible. Likewise, the movable partition 61 can be arranged to be movable inside enclosure 62 instead of 60. Both the enclosure 60 and enclosure 62 are typically supported by at least one wheel or pair of wheels. Depending on the need for stability and the weight of the fully loaded trolley, the enclosure 60 can have e.g. 2 or 4 wheels while the enclosure 62 can have 1 or 2 wheels. However, any number of wheels may be used.

[0047] In the configuration of figure 6b, the movable separation 61 is at the front side (right side in figure 6b) of enclosure 60, so that the full space of enclosure 60 is available for shelf 25 and clean linen. The shelf may be attached to the separation 61 on one side and supported by shelf supports 65. The enclosure 62 is slid over the enclosure 60 to the maximum extend, so that the space for the soiled linen compartment 14 is minimal. This is the typical configuration for moving a trolley 10 (or at least the linen compartment 20) full of clean linen from the washing station to the hotel. No space will be taken up by an empty soiled linen compartment 14.

[0048] In the configuration of figure 6c, the movable separation 61 has been moved partially towards the rear (left) side of enclosure 60, thereby reducing the amount of space for clean linen in clean linen compartment 13. Shelf 25 is partly folded to fit in the reduced space. The enclosure 62 is partially extended, so that a relatively large space is available for soiled linen compartment 14. This is the typical configuration when the trolley 10 is in use during a cleaning round, when the clean linen has already been partially distributed and soiled linen is being collected.

[0049] I n the configuration of figure 6d, the movable separation 61 has been moved all the way to the rear (left) side of enclosure 60 and shelf 25 has been folded, thereby reducing the amount of space for the clean linen compartment 13 to a minimum. Meanwhile, the second enclosure 62 has been slid over the first enclosure 61 to the maximum extent possible given the load of soiled linen. In an ideal case, the total volume of the linen module 20 is the same as in figure 6b, for transport of the soiled linen back to the washing station.

[0050] In a variant of figure 6d shown in figure 6e, the soiled linen compartment 14 is provided with an airtight enclosure, for example a plastic bag 66. When the trolley is in use for collecting soiled linen, the bag is open (e.g. using an airtight zipper or other means of open/close sealing) for inserting soiled linen. When the bag is full, the bag is closed airtight. The bag 66 is provided with a one-way valve 67 which is accessible from the outside of the second enclosure 62. When the second enclosure 62 is pushed over the first enclosure 60, the air in the airtight enclosure 66 is forced out through the valve 67 and the volume of the soiled linen compartment 14 is reduced. This is advantageous in order to reduce the volume of the linen compartments 20 as much as possible before the trolley 10, or at least the linen compartments 20, are loaded into a vehicle for transport to a washing station.

[0051] As an alternative to forcing the air out of the airtight enclosure 66 through pushing, the air can be sucked out using e.g. a vacuum hose 31 connecting the valve 67 to a pump as described in reference to figures 3 and 4.

[0052] Figure 7 shows a hotel trolley with an upper module 72 according an embodiment of the invention. The upper module 72 rests on a U-shaped support 71 and has an upper clean linen compartment 13' and an upper soiled linen compartment 14', separated by upper separation 75. The upper clean linen compartment 13' has a door with handle 73. The upper soiled linen compartment 14' has a flap 74 for depositing soiled linen. The upper module provides some extra space for clean and soiled linen.

[0053] Variations to the upper module shown in figure 7 are possible. The module can comprise a single compartment for clean linen, for example with a door or set of doors facing the rear of the trolley. For example, when at the end of the cleaning round, still some clean linen is left over in clean linen compartment 13 (as e.g. shown in figure 6c), this surplus clean linen can be moved to the upper module so that the linen compartment 20 can be made as compact as possible, reducing the space for the clean linen compartment 13 to the minimum. That way, linen compartment 20 with the soiled linen in compartment 14 takes up as little volume as possible in the transport to the washing station.

[0054] Figure 8 shows a hotel trolley with an external motorized part according an embodiment of the invention. Detachable engine block 80 may include a battery and electric motor and means for driving set of wheels 81 . The remaining wheels 12 can be passive, free-rotating wheels. The engine block 80 can be easily connected to a connection part of either the trolley 10 body or linen compartment 20. By making the engine block 80 attachable / detachable, the engine block 80 need not to be shipped to the washing station each time the linen compartment is sent there, saving weight in transport. Instead, the engine block 80 can remain in the hotel semi-permanently, and be recharged using power from an electric socket after a cleaning round.

[0055] I n the foregoing description of the figures, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the scope of the invention as summarized in the attached claims.

[0056] In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

[0057] I n particular, combinations of specific features of various aspects of the invention may be made. An aspect of the invention may be further advantageously enhanced by adding a feature that was described in relation to another aspect of the invention.

[0058] For example, the foldable and slidable shelves of figure 2a-2d can be combined with any of the hotel trolleys described in this application. Likewise the vacuum sealing system of figures 3 and 4 can be combined with features from any embodiment, such as those of figures 6a-6d and 7-8. Also the RFI D tag readers, scanners, and weight sensors can be used in any combination with other embodiments, including those of figures 2a-d and 6a-e and 7-8. The upper compartment of figures 7 and 8 can be combined with other embodiments (e.g. those of figures 1 -6) as, can the external detachable engine block of figure 8. [0059] It is to be understood that the invention is limited by the annexed claims and its technical equivalents only. In this document and in its claims, the verb "to comprise" and its conjugations are used in their non-limiting sense to mean that items following the word are included, without excluding items not specifically mentioned. In addition, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one".