EP1236545A2

EP1236545A2 - Power tool body

Info

Publication number: EP1236545A2
Application number: EP02004485A
Authority: EP
Inventors: Sion Netzler
Original assignee: Black and Decker Inc
Current assignee: Black and Decker Inc
Priority date: 2001-03-02
Filing date: 2002-02-27
Publication date: 2002-09-04
Also published as: GB0105140D0; EP1236545A3

Abstract

A power drill/driver (6) is formed from a plurality of components. Two mirror-image body portions (2, 4) are brought together about a centre line and then a shrouding (34) is placed over the rear indented portion (28) of the composite tool (6). The tool so formed has greater structural rigidity than a tool formed from conventional clamshell or body halves without such a shrouding thereover. <IMAGE>

Description

The present invention relates to bodies for power tools as set out in the preamble of claim 1 below.

It is well known in the field of power tools and, particularly power drills, to include inserts such as so-called "soft grips" on the tool body. These soft grips are generally used as means of clamping or cushioning any vibration felt by the user of the tool during use. Alternatively or additionally such an insert could take the form of a high friction insert.

Most power tools have bodies formed of plastics material, the shape of which is usually achieved by way of injection moulding. This manufacturing technique is particularly suitable for high-volume production, as is the case for power tools. Furthermore, power tool bodies are usually injection moulded in two mirror-image halves. The halves are chosen either side of a plane extending longitudinally along the body of the tool.

Frequently the mould for the tool body includes portions shaped to impart recesses or cut-outs to the finished body. The purpose of these cut-outs is to allow an over-moulding or insert, as briefly mentioned above, to be attached to the body after the initial injection moulding procedure. Such over-moulding or inserts may, for example, be advertising stickers or even so-called "soft-grip" additions.

Inserts are commonly attached to the body of a tool to aid in a user being able to grip the tool during use thereof, or to reduce the amount of vibration felt by the user by acting as a crude clamping mechanism.

In the case of an insert aiding the user's grip on the tool, the material is chosen to have a high degree of friction at its surface. In the case of the soft-grip acting as a damper, the material of the soft-grip is chosen to be resilient, such as rubber or the like.

The positioning on the tool body of the insert is also important. In the case of an insert being used for increased grip, then it should be positioned on that part of the tool, which, in use, a user tends to hold. In the case of an insert used for vibration damping, it is best positioned on that part of the tool at which the user most feels the effects of vibration during, for example, a hammer drilling procedure.

Furthermore, in the case of any type of insert, they are applied to the body as a permanent structure. This is in addition to the fact that the portion of the body to which the insert is attached is made to accept a dedicated insert. This means there is no facility to alter or change the type or nature of insert attached to the body.

In addition, the known inserts which are attached to a portion of the body serve no structural support purpose. Although they are functional, rather than decorative, they are only attached to the surface of the body rather than forming part of the framework, or structural support to the body structure.

It has been found that, by forming the body of a power tool with an entire surface being only part-formed or skeletal, then a novel form of insert can be attached thereto (or formed thereover) which adds rigidity and/or support to the body. Also, this novel insert can be easily replaced with another type having the same dimensions. For example, a frictional-grip insert can be exchanged for a vibration-damping insert.

Furthermore, the above results from a novel style of manufacture which enables the rapid exchange of inserts. Also, this style of manufacture results in a different type of power tool than has been hitherto known.

According to the present invention, therefore, there is provided a body for a power drill/driver of the known type characterised in that;

the indented region not only spans each of the two mirror-image moulded portions, but also extends along a substantial portion of, and extends between, the rearward section and the handle portion of the drill/driver body;

the drill/driver body further including a detachable portion for removable attachment to the indented region of the drill/driver body;

and wherein the detachable portion, when attached to the drill/driver body, overlies and encapsulates the entire indented region of the drill/driver body.

Whilst it would usually be thought that forming a tool body with an indented region would weaken the structure of the body, by overlying and encapsulating this region with the detachable portion, a high degree of support and rigidity is imparted to the body. Clearly the body is now held also by an extra element which would otherwise be absent if the body comprised only two mirror-image halves.

According to a preferred embodiment the detachable portion forms a cover member for the indented region. By suitable choice of the thickness of the detachable portion, therefore, the outer surface of the tool can be smooth by making the surface of the detachable portion flush with the surface of the remainder of the tool body.

Additionally or alternatively, the detachable portion may be formed from the same or different material from that of the drill/driver body, dependent upon the purpose for which the detachable portion is to be used.. This allows a great deal of flexibility during the manufacturing process. For example, in certain circumstances it could be desirable to have the detachable portion formed from a rigid material such as glass-filled nylon. In another example, it may be desirable to coat the detachable member with ― or even form it from ― a resilient material such as a rubber or the like. It is even possible to use this flexibility to achieve design changes to the body of the drill/driver. For example, different shape or colour detachable portions can be applied to, or interchanged on the indented region of the drill/driver.

Preferably, the indented region interfaces with the rearward section and the handle portion of the drill/driver via a curved or arcuate surface. This allows for an ergonomic design to be applied to the finished drill/driver. Furthermore, the curved or arcuate surface may be continuous and it may extend form the rearward section to the handle portion.

An embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying drawings of which:-

Figure 1 shows a rear view of the indented portion of a body for a power drill/driver in accordance with the present invention;

Figure 2 shows a view taken along the line X-X of figure 1 and shows a side view of the internal portion of one of the clamshell halves forming the drill/driver body;

Figures 3a and 3b show respectively a perspective view and a side view of the attachment of a detachable member to the indented region of the drill/driver of Figures 1 and 2;

Figures 4a and 4b show more advanced stages of Figures 3a and 3b respectively;

Figures 5a and 5b show the almost complete attachment of the detachable portion to the indented region of the power tool body as shown in Figures 3 and 4;

Figures 6a and 6b show the completed attachment of the detachable portion to the indented region of the power tool body following on from Figures 3, 4 and 5, and;

Figure 7 shows a rear view of a power tool body (as shown in Figure 1) but with the detachable portion attached to the indented region thereof.

Referring firstly to Figure 1, there is shown a rear view of part of a body for a power drill/driver formed from a first body portion (2) and a second body portion (4). The body portions (2, 4) are mirror-images of each other and are brought together about a central split line shown by the line X-X in Figure 1. In fact, the line X-X in this example forms a plane of portion (2, 4) registration which plane bisects the drill/driver body longitudinally. The drill/driver body is a composite structure shown generally as (6) in Figure 1.

The body portions (2, 4) are formed, in known manner, by, for example, injection moulding of plastics material into a mould (not shown) shaped so as to define two mirror image portions (2, 4). Any suitable material which can be utilised in an injection moulding process can be used to form the body portions (2, 4). In this example, glass-filled nylon is used which may also include colour dyes in order to selectively colour the body (6) so formed.

Reference now also to Figure 2 shows the internal view of the body portion (2) of Figure 1 along the line X-X thereof. It can be seen that this moulded portion (2) includes a plurality of bosses (8) formed on the internal surface thereof. The mirror image body portion (4) also has complementary spigots (not shown) of a slightly different diameter to mate with the bosses (8) formed on body portion (2). In this manner, registration between the two body portions (2, 4) can be achieved when they are brought into contact with each other along the plane of registration X-X. Furthermore, the two body portions so brought together may then be coupled to each other by way of screws passing through the bosses (8) and spigots. It will be understood that in this example the bosses formed on the body portion (4), have internal screwthreads formed therein to couple with the thread of a screw (not shown) passing through the other body portion (4) spigots into engagement with the bosses (8) shown in Figure 2.

It can be seen that housed within the body portion (2) is a motor (10) for the drill/driver which is operatively coupled to a gearbox (12) which drives an output spindle (14) for imparting rotary motion to either a drill bit or a screwdriver bit, etc.

The body portion (2) is shaped to provide a forward section (16) including an aperture (18) through which the output shaft (14) projects. Furthermore, a rearward section (20) of the body (6) not only houses the motor (10) but is also directly adjacent and, in this example, becomes a handle portion (22). The handle portion (22) is held by a user in use of the power tool. It will be appreciated, however, that the rearward section (20) and the handle portion (22) could be separate items coupled together to form a unitary composite structure.

It can also be seen from Figure 2 that a cavity (24) is formed in the body portion (2) for mounting a trigger for the drill/driver, actuation of which causes the motor (10) to provide a rotary force on the output shaft (14). Furthermore, a lower housing (26) may, in the case of the drill/driver being of a cordless type, house a battery or batteries for providing power to the motor (10).

Although it cannot be particularly readily discerned from Figures 1 and 2, the rearward section (20) and handle portion (22) includes an indented region of the drill/driver body (6). This indented region can be seen at (28) in Figure 2 and it follows the outer peripheral shape of the rearward section (20) and handle portion (22) and terminates at the lower housing (26), although this cannot be seen from Figure 2.

Reference now also to Figures 3, 4, 5, 6 & 7 shows the indented region (28) in greater clarity. In fact, the indented region (28) can be seen from Figure 1 (but this is the entire view of Figure 1) as, in this example, the indented region extends along the entire length of the rear of the body portion (6) from its uppermost point (30) in Figure 1 to its lowermost point (32). Although in the example shown the indented region (28) extends along an entire surface of the drill/driver body (6), this need not necessarily be the case. The indented region (28) may extend only along a portion of a surface of the drill/driver body (6), but it must extend along a substantial portion of the rearward section and the handle portion and must extend therebetween. The reasons for the extent of the indented region (28) will be described below.

Referring now also to Figures 3 - 7, it can be seen that the body (6) for a power drill/driver includes a further portion, here a detachable portion in the form of a shrouding (34). The shrouding (34) is removably attachable to the indented region (28) of the body portions (2, 4). Indeed, it can be seen from Figures 3 - 6 in particular that the indented region (28) is formed integrally with the remainder of the body portions (2, 4) but is formed using less material and, in this example, does not have a suitable surface finish. Therefore, as one moves from the smooth finished surface (36) of body portion (2) or (4) toward the indented region (28), there is an interface (38) between the two.

It can be seen that the shrouding (34) has a plurality of projecting lugs (40) formed thereon. Indeed the lugs (40) may be formed integrally with the remainder of the shrouding, or may be formed as additional components. There are a plurality of co-operable apertures (42) formed in the body portions (2, 4) into which apertures the projecting lugs (40) may be press-fitted. In addition, the body portions (2, 4) each carry an integral screwthread (44) therein and the corresponding portion of the shrouding has formed therein recesses (46) through which screwthreads may pass in order to securely fasten the shrouding (34) to the body portions (2, 4).

The above allows the shrouding (34) to be releasably connectable to the body portions (2, 4) and to overlie and encapsulate the indented region (28) of the drill/driver body (6) formed thereby.

Referring now particularly to Figures 5a and 5b, it can be seen how the shrouding (34) is brought into engagement with the indented region (28). Firstly, the upper projecting lugs (40) are brought into engagement with their co-operable apertures (42). Referring now particularly to Figures 6a and 6b, it can be seen that the lower lugs (40) are brought into engagement with the lower co-operable apertures (42) which then ensures that the shrouding (34) is completely attached to and encapsulates the indented region (28). All that remains to securely fasten the shrouding (34) to the body (6) is to drive screws through the recesses (46) and into the screwthreads (44) (which cannot be seen from Figures 6a and 6b).

Reference now also to Figure 7 shows the rear view of the shrouding (34) once it is in place around the indented region (28) of the body (6).

It will be appreciated by those skilled in the art that, once the shrouding (34) is in place as shown in Figures 6 and 7 that the completed construction of the body (6) which includes the two body portions (2, 4) in addition to the shrouding (34) has considerable strength and rigidity compared to situations known in the prior art where the body member would otherwise have been formed simply from two clamshell halves such as body portions (2, 4). Because the completed structure of the body (6) of the drill/driver is formed in three parts which come together in the arrangement shown then the drill/driver so formed will tend to have a greater endurance than bodies of drill/drivers that have been hitherto known.

It can be seen particularly from Figure 1 that the mirror-image portions (2, 4) span the entire indented region (28) about their plane of registration X-X. It can also be seen from Figures 3 - 6 that the shrouding (34) totally surrounds and encapsulates the indented region (28) and, therefore, those parts of the body portions (2,4) within the indented region (28) also.

It will further be seen that, in the embodiment shown in the attached drawings the interface (38) is formed as a curved or arcuate surface. Such an arcuate surface is chosen to allow for accurate placement of the shrouding (34) as shown in Figures 3, 4, 5 & 6, which depict the way in which the shrouding (34) is attached to the indented region (28). However, any suitable shape of interface (38) will allow the advantages of the invention to accrue such as straight, stepped, castellated, etc.

It was stated above that the extent to which the indented region needs to be formed along the relevant portion of the body (6) of the drill/driver is "substantial". Although no quantitative limits need to be placed upon this term, it is to be understood that one of the purposes of the shrouding (34) is to be able to overlie and encapsulate the entire indented region of the drill/driver body (6) and this enables a rigidity to the completed tool which has hithertofor not been available. Clearly, if the extent to which the indented region (28) subsists is very small in relation to the overall rear surface of the body (6) as shown in the attached drawings, then this object is unlikely to be achieved. Thus, it is preferable for the indented region (28) to extend over the entire rear surface as shown in the figures, but a lesser extent which still achieves the aims stated above is still efficacious.

In the examples shown, the shrouding (34) is chosen to be of glass-filled nylon sub-structure with a resilient rubber over-moulding. The glass-filled nylon sub-structure is seen most readily from Figures 3-6 as reference numeral (48) and the rubber over-moulding as reference numeral (50). The method by which a rubber over-moulding (50) is held to a glass filled nylon substructure (48) is well known to those skilled in the art and so will not be discussed further herein.

There are different types or forms of shrouding (34) which can be chosen in accordance with the present invention dependent upon the purpose to which the shrouding (34) is put. For example, if the shrouding (34) is chosen simply to provide a rigid "cage" or shroud for the composite tool body (comprising the body portions (2, 4) and the shrouding element (34)) then glass-filled nylon or some other suitably hard plastics material is acceptable. Alternatively, should the purpose of the shrouding (34) be to aid in absorbing vibration of the drill/driver during use then the shrouding (34) may be formed of or include resilient material such as rubber or the like.

In addition, by choosing a detachable shrouding (34) it is possible to achieve various aesthetic design features, such as different coloured shroudings (34) to indicate, for example, the purpose to which the drill/driver is put, its torque, or power or speed outputs, etc. Alternatively, it may be used for altering decorative effects for that part of the drill/driver body.

In the above description it is stated that the mirror image body portions (2, 4) are brought into co-operable registration. This means that they are brought together about the plane which bisects the body longitudinally, namely X-X of Figure 1. Only when the two halves (2, 4) of the composite tool (6) are brought together in registration is the outline shape that is shown in the attached drawing. Clearly, if the 2 body portion halves (4, 6) do not register co-operably then they will be misaligned and the composite tool (6) will not be complete. Not only will this mean that the two halves (4, 6) cannot be coupled together, but also it will then not be possible for the shrouding (34) to be attached thereto.

Claims

A body for a power drill/driver formed from a plurality of moulded portions, two of which moulded portions are formed as mirror images of each other and are co-operable to define the body having a plane of portion registration, which plane of portion registration bisects the drill/driver body longitudinally;
the drill/driver body formed from co-operable registration of said two mirror-image portions also defining a forward aperture through which an output shaft of the drill/driver is accessible and a rearward section within which a motor of the drill/driver is housed and further defining a handle portion of the drill/driver directly adjacent the rearward portion thereof;
the surface of the drill/driver body so formed by co-operable registration of said two mirror-image portions also defining a region indented with respect to the remainder of the surface of the drill/driver, characterised in that;
the indented region not only spans each of the two mirror-image moulded portions, but also extends along a substantial portion of, and extends between, the rearward section and the handle portion of the drill/driver body;
the drill/driver body further including a detachable portion for removable attachment to the indented region of the drill/driver body;
and wherein the detachable portion, when attached to the drill/driver body, overlies and encapsulates the entire indented region of the drill/driver body.
A body for a power drill/driver according to claim 1 wherein the detachable portion forms a cover member for the indented region.
A body for a power drill/driver according to either one of the preceding claims wherein the detachable portion may be formed from the same or different material from that of the drill/driver body, dependent upon the purpose for which the detachable portion is to be used.
A body for a power drill/driver according to any one of the preceding claims wherein the indented region interfaces with the rearward section and the handle portion of the drill/driver via a curved or arcuate surface.
A body for a power drill/driver according to claim 4 wherein the curved or arcuate surface is continuous.
A body for a power drill/driver according to claim 5 wherein the continuous curved or arcuate surface from the rearward section to the handle portion.
A body for a power tool according to any one of the preceding claims wherein the detachable member includes a plurality of bosses for aligning the detachable member with the moulded portions.