CONSTRUCTION OF A MULTI-PART HAIR CLIPPER WITH A METAL OUTER CASING

Abstract

A hair clipper is provided comprising a chassis (12) having upper and lower portions (14, 16) of the chassis defining a closed inner chamber (18), said upper and lower portions of the chassis configured to be secured together; and an outer casing (20) including upper and lower portions (22, 24) of the casing constructed and positioned to enclose the chassis as the casing portions are secured together so that the inner chamber is isolated from the casing.

Description

The present invention relates to electric hair cutting devices commonly known as hair clippers or hair trimmers and more specifically relates to a multi-component hair clipper construction featuring metallic outer casing parts. Conventional electric hair clippers and trimmers, collectively referred to herein as hair clippers, have an internal chassis on which a motor, electrical controls, batteries or AC power cords, or a power transmission link to the blade assembly are mounted. This structure is then covered by an external housing, typically the upper and lower clamshell portions that are attached to the chassis by threaded fasteners. In most cases, the external housing is made of molded plastic parts. A key objective for hair clipper designers is to reduce vibration and noise from the motor and blade assembly. Another objective is to reduce the number of parts required for production and to lower assembly costs. A more recent area of ​​interest for designers is the ability to replace traditional plastic housings with metal ones. A current challenge is that metal housings are less tolerant of variations in tolerances compared to plastic parts. As such, achieving high-quality, aesthetically pleasing, and tight-fitting components assembled in a factory environment is a significant challenge for clipper designers. Furthermore, modern hair clippers commonly feature housings with separate decorative pieces made of metal, plastic, or plastic with metal or metal foils that preferably fit tightly to the housing.The resulting challenge for hair clipper designers is to balance many often conflicting design considerations: accommodating multiple parts with varying tolerances to achieve an aesthetically pleasing appearance while also securing the operating components in a way that reduces vibration and noise. Consequently, there is a need for improved hair clipper construction that addresses the design criteria listed above. The aforementioned need is met or exceeded by the present multi-piece hair clipper design, which includes a central chassis having upper and lower portions configured to house the motor and electronic control components, and a portion of the blade assembly's power transmission. Furthermore, since the chassis is preferably made of plastic, the internal components (motor, switch, circuitry, power cables, etc.) are preferably protected from electrical interference by the metal housing portions, including the upper and lower portions, which enclose the chassis. In the preferred embodiment, the housing is made of cast polished aluminum; however, other metals, as well as selected plastics or engineering materials incorporating known material blends, are contemplated.By employing the present cutter construction, the relatively high voltage of 120-230 V of the preferred cutter motor is electrically isolated from the metal housing. The lower portion of the chassis includes a motor recess designed and positioned to accommodate the electric motor, preferably a vibrator type; however, other motors commonly used in hair clippers are also suitable. Integral crush ribs are also incorporated into the lower chassis, securing the motor in place with a friction fit that tightens as the chassis is assembled. Hanging wedges on the upper part of the chassis engage in the recesses of the crush ribs to further secure the motor as the chassis parts are locked together. Threaded fasteners capture the motor between the upper and lower chassis without clamping it tightly. That function is performed by the crush ribs, which press harder against the motor as the upper chassis is tightened.Because the motor is securely mounted between the upper and lower portions of the chassis, this assembly has been found to reduce motor noise and vibration compared to conventional mower assembly technology. Therefore, in this mower, the motor is electrically isolated from the metal housing. Also included in the lower chassis is an integral blade guide channel that replaces a separate metal bracket found in conventional hair clippers. The blade guide channel is defined by a formation at one end of the chassis blade that also defines a travel path for a cam follower. As is known in the art, the cam follower moves transversely to a longitudinal axis of the clipper and parallel to the movement of a moving blade in the blade assembly. A third function of the blade guide channel is to define an angled seat for a leading edge of the lower housing, which, as described above, is preferably made of metal. In addition, relatively soft rubber grips, provided for user comfort, are attached to the sides of the clipper.These grips create compression zones to accommodate variations in the metal housing tolerance, ensuring a tight fit between the housing and grips without gaps or unsightly misalignment. In other words, the grips are sized slightly larger and designed to compress without bulging when the upper and lower housing portions are attached to the chassis. In the preferred embodiment, each grip loosely engages along the upper and lower edges of the assembled chassis using a hook-and-loop system. In a preferred embodiment, the hook-and-loop connection system includes at least one ramped hook on the chassis and at least one complementary loop on the attachment, with each hook surrounded by a rest that receives the hook.Also, in one embodiment, the handle has at least one loop projecting from a top edge and at least one loop projecting from a bottom edge. Furthermore, each handle includes at least one supplementary grip formation at at least one front and one rear end, and the chassis is configured to receive each supplementary grip formation via a snap-fit ​​connection. By loosely attaching the grips to the chassis, the grips can move or “float” to accommodate variations in the rigid parts of the metal housing. The grip material compresses as needed as the upper and lower portions of the housing are secured together with the chassis captured between them. Yet another feature of the present cutter is a clamping system for retaining ornamental badges or decorative pieces within a metal housing of the cutter, achieving a tight, aligned fit without the use of threaded fasteners. Achieving such a fit is challenging, given the variability in the dimensions of the cast and polished metal housing. The decorative piece is provided with at least one, and preferably multiple, unsupported hook projections extending into the interior of the cutter. A retainer is positioned on the underside of the housing, configured with multiple complementary projections that engage the hook projections of the decorative piece in a press-fit relationship.In a preferred embodiment, the retainer includes two types of projections, a first plurality of flat projections and a second plurality of dog-leg projections, the latter of which are configured to exert a preloaded clamping force on the projections of the decorative piece. In one embodiment, the chassis includes a projection recess to accommodate the hook and such retaining projections. Furthermore, the lower and upper portions of the housing are provided with mounting protrusions configured to project through matching holes in the chassis, such that fasteners passing through the protrusions securely retain the chassis between the upper and lower portions of the housing. Also, at least one of the housing portions includes at least one locating formation projecting from the interior of a portion of the housing and mating coincidentally with at least one matching receiving formation on the chassis. More specifically, a hair clipper is provided, which includes a chassis having upper and lower portions of the chassis defining a closed inner chamber, the upper and lower portions of the chassis configured to be secured together, and an outer casing including upper and lower casing portions constructed and positioned to enclose the chassis as the casing portions are secured together so that the inner chamber is isolated from the casing. In another embodiment, a hair clipper is provided, including a chassis having upper and lower chassis portions defining a closed inner chamber, the upper and lower chassis portions configured to be secured together. An outer casing includes upper and lower casing portions constructed and positioned to enclose the chassis as the casing portions are secured together so that the inner chamber is isolated from the casing. The inner chamber includes a motor recess and a motor retained in the motor recess by close cooperation of complementary formations in the upper and lower chassis portions and elastic clamping formations loosely connected to the chassis and constructed and positioned to compress upon assembly of the upper and lower casing portions. 7.R} bnn / P7n7 / B / YIAI In yet another embodiment, a method for assembling a hair clipper includes providing a chassis having upper and lower chassis portions defining a closed inner chamber, said upper and lower chassis portions configured to be secured together, providing an outer casing including upper and lower casing portions constructed and positioned to enclose the chassis as the casing portions are secured together so that the inner chamber is isolated from the casing; providing the chassis with a first blade end and a second rear end, and the blade end includes an integral blade guide channel. The blade guide channel is oriented at an oblique angle to an axis defined by the chassis, and the lower casing portion has an angled front edge that slides along the receiving surface of the casing. BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a top perspective assembled view of the present hair clipper. Figure 2 is an exploded perspective view of the hair clipper in Figure 1. Figure 3 is an exploded perspective view of the chassis of the present hair clipper. Figure 4 is a partially disassembled side elevation of the present hair clipper. 7.R} bnn / P7n7 / B / YIAI Figure 5 is a partially disassembled rear perspective of the hair clipper shown in Figure 4. Figure 6 is a fragmentary, enlarged top perspective view of the present hair clipper showing the blade assembly. Figure 7 is a partially disassembled perspective rear view of the present hair clipper showing the detail of the side gripping pads. Figure 8 is a cross-section taken along lines 8-8 of Figure 1 and in the generally indicated direction. Figure 9 is an enlarged fragmentary view of the hair clipper depicted in Figure 8. Figure 10 is a cross-section taken along line 10-10 of Figure 1 and in the generally indicated direction. Figure 11 is an enlarged fragmentary top view of the present hair clipper with portions omitted for clarity. 7.R} bnn / P7n7 / B / YIAI Figure 12 is a fragmentary front perspective view of the present hair clipper with portions omitted for clarity. Figure 13 is a top perspective view of the hair clipper in Figure 12. Figure 14 is a cross-section taken along lines 14-14 of Figure 13 in the generally indicated direction. Figure 15 is a fragmentary vertical cross-section taken along line 15-15 of Figure 1 and in the generally indicated direction. Figure 16 is a vertical cross-section taken along line 16-16 of Figure 1 and in the generally indicated direction. Figure 17 is a partially exploded top perspective view of the hair clipper in Figure 1 with portions omitted for clarity. Figure 18 is an enlarged fragmentary top perspective view of the hair clipper in Figure 1 with portions omitted for clarity. Figure 19 is a top perspective view of the ornamental design element of the present hair clipper. Figure 20 is an enlarged top perspective view of the element in Figure 19 and 7.R} bnn / P7n7 / B / YIAI Figure 21 is an exploded top perspective view of the ornamental design element in Figure 19. DETAILED DESCRIPTION OF THE INVENTION Now, with reference to Figures 1-3, the present hair clipper is generally designated 10 and includes a chassis 12 having lower and upper chassis portions 14, 16 defining a closed inner chamber 18 (Figure 3). The upper and lower chassis portions 14, 16 are constructed and positioned to be fastened together, such as with threaded fasteners or the like. For the purposes of this application, “upper” and “lower” refer to the orientation of the hair clipper 10 as shown in the drawings, which is the same as the orientation of the clipper when resting on a substrate such as a table or stylist's workstation. Other orientations of the clipper 10 during use are contemplated. Enclosing the chassis 12 is an outer housing 20, including upper and lower housing portions 22, 24, constructed and positioned to enclose the chassis 12. The housing portions are secured together so that the inner chamber 18 is isolated from the housing. In the preferred embodiment, the chassis 12 is made of electrically insulating material such as injection-molded plastic or the like, and the outer housing 20 is made of metal, preferably cast and polished aluminum or the like, or other metals or composite materials known in the art. As described later in more detail, the chassis 12 is provided with various features to accommodate variations in the dimensions of the outer housing 20 caused by the casting and polishing process, so that the hair clipper 10 is easily assembled and the respective components are fully aligned for a quality appearance. As known in the art, the hair clipper 10 is also provided with a set of blades 26 including a stationary blade 28 and a blade 30 that moves alternately laterally, each blade having a corresponding plurality of teeth 32, 34. The cutting action occurs as the movable blade 30 moves alternately with respect to the stationary blade 28. An adjusting lever 36 is connected to the chassis 12 and to the stationary blade 28 and is configured to move the stationary blade with respect to the movable blade 30 as known in the art. The chassis 12 has a first or blade set end 38 and a second, opposite or rear end 40. At the rear end 40, a cable protector 42 is secured to the chassis 12 to protect a power cord as known in the art. The present hair clipper 10 is intended to be powered by AC wall current or by battery power, in which case the cable protector 42 is eliminated. Between the upper and lower portions of the casing 22. 24 are located relatively resistant rubber grips 44, described in more detail later. Also included in the outer casing 20, and preferably in the upper portion 22 of the casing, is a decorative piece or ornamental badge 46, also described in more detail later. } frnn / eznz / e / YiAi Now, with reference to Figures 3 and 8-11, within the inner chamber 18 of the chassis 12 is a motor recess 48 sized to accommodate an electric motor 50. Preferably, a vibrator motor of the type described in U.S. Common Property Patents Nos. 5,787,587; 7,239,053; and 8,276,279, all of which are incorporated by reference and such motors are well known in the art. However, other types of electric motors commonly used in hair clippers are contemplated. One of the features of the present clipper 10 is that the motor 50 is secured in place within the inner chamber 18 of the chassis 12 in such a way as to reduce operational noise and vibration, and that the motor is installed with less labor compared to conventional hair clippers.For this purpose, the engine 50 is held in the engine recess 48 through the cooperation of the complementary formations 52, 54 respectively in said upper and lower portions 14, 16 of the chassis, however it is contemplated that the arrangement of the formations may be reversed depending on the application. In one embodiment, the complementary formations 52, 54 (Figures 3, 8, and 10) include crush ribs 56 formed integrally in the lower portion of the chassis 16. More specifically, the crush ribs 56 include an inner wall 58 configured to engage firmly and slidably with an outer surface 60 of the laminations 62 of the engine 50. Behind the inner wall 58, a cavity 64 is defined, partially enclosed by an outer wall 66 of the chassis portion 16. In the upper portion 14 of the chassis, the formations 52 take the form of hanging wedges in the other portion of the chassis, the wedges being engaged in the cavities 64 of the crush ribs.Wedges 52 and cavities 64 are constructed and positioned so that the upper and lower portions of chassis 14, 16 are secured together around the motor 50. Wedges 52 increase the clamping force of the crush ribs 56 on the motor. The action of the complementary formations 52, 54 is the primary structure that secures the motor 50 within the motor recess 48. In addition, the hair clipper 10 is provided with threaded fasteners 68 used to secure the chassis portions 14, 16 together. As shown in Figures 9 and 11, the fasteners 68 fit loosely within the holes 70 in the motor 50, and as such, position the motor within the motor recess. Now, with reference to Figures 2, 4, 5, 7, and 18, another feature of the present hair clipper 10 is the use of heavy-duty handles 44 to accommodate manufacturing variations in the upper and lower portions of the housing 22, 24 so that the final assembly has an aesthetically pleasing appearance without unsightly gaps between components. As such, the handles 44 are dimensioned with a slightly oversized peripheral edge 72 so that the corresponding edges 74, 76 of the upper and lower portions of the housing 22, 24 exert a compressive force on the handles 44 during assembly. To improve the ability of the grips 44 to adapt to the manufacturing variations described above, it is preferred that the grips be connected to the chassis in a relatively loose manner. In the preferred embodiment, the connection is achieved by a hook-and-loop connection system. While it is contemplated that the grip 44 or chassis 12 be provided with hooks and the other component be provided with loops, in the preferred embodiment, the grips 44 are provided with at least one, preferably a plurality of loops 78 projecting laterally or generally horizontally from an inner surface 80 of the peripheral edge 72. Each of the loops 78 has a relatively large opening 81. Engaging each loop 78 is a ramp hook 82 on the chassis 12. Each hook is loosely engaged in the opening 81 and is progressively taller towards a longitudinal axis of the chassis 12. Surrounding each hook 82 is a generally flat rest 84 (Figure 3) preferably configured to complementarily receive an outer edge 86 of the loop 78 (Figure 7). In the preferred embodiment, each handle 44 has at least one, and preferably a pair of, loops 78 projecting from a top portion of the edge 72, and at least one, and preferably a pair of, loops 78 projecting from a bottom portion of the edge 72. Now, with reference to Figures 2, 7, and 8, the handles 44 are further secured to the chassis 12 by means of at least one supplementary clamping formation 88 on at least one of a front end 90 and one rear end 92 of the handle, and the chassis 12 is configured with openings 94 to receive each supplementary clamping formation in a press fit. In the preferred embodiment, the supplementary clamping formations 88 are provided with barbed ends 86 (Figure 7). As shown in Figure 7, in the preferred embodiment, one of the handles 44 is provided with an opening 98 to accommodate an ON / OFF switch 100. } πηη / ρζηζ / Β / γίΛΐ Now, with reference to Figures 1-6 and 11-14, another feature of the present hair clipper 10 is that the chassis 12 has the first blade end or blade set and the second, rear end 40, and the blade end includes an integral blade guide channel 102. As is well known in the art, hair clippers are provided with a supplementary metal guide support to accommodate the sliding movement of the stationary blade 28 transverse to the lateral reciprocating cutting motion. In the present clipper 10, the conventional support is replaced by the channel 102, which is defined by an enlarged formation 104 oriented at an oblique angle α to the longitudinal axis “A” of the chassis (Figure 4). While other angles are contemplated, in the preferred embodiment, the angle α is 60°. As shown in Figures 1, 5 and 6, the blade guide channel 102 slides into a generally U-shaped support 106 secured to the stationary blade 28 and also receives the adjusting lever 36, which is threaded to the formation 104. Through an eccentric cam (not shown) in the adjusting lever 36, the movement of the adjusting lever 36 causes the sliding action of the support 106 and the blade 28 in the channel 102. Now, with reference to Figures 11-14, another function of the blade end formation 104 is that it defines a travel path 108 for a cam follower 110, which is used to transfer the lateral reciprocating motion of the motor 50 to the moving blade 30, using a drive arm 111 (Figure 11). The travel path 108 extends transversely to the longitudinal axis of the chassis 12. In addition, the formation 104 defines a central opening 112 (Figure 12) that accommodates the reciprocating motion of the cam follower 110. Now with reference to Figures 4-6, yet another feature of formation 104 is defining a receiving surface of the housing 114 oriented at an oblique angle, preferably angle α, to slideably receive an angled front edge 116 of one of the upper and lower portions of the housing 22, 24, preferably the lower portion of the housing 24. During the assembly of the hair clipper 10, once the chassis 12 is clamped together, the lower portion of the housing 24 slides into the lower portion of the chassis 16 so that the front edge 116 slides angularly and slidably engages the receiving surface 1147 in the direction of arrow “B” (Figure 6). Now, with reference to Figures 16-21, an additional feature of the present hair clipper 10 is its ability to securely accommodate the separate badge or decorative piece 46, despite variations in the manufacturing tolerances of the associated housing portion 22, 24. In the preferred embodiment, the decorative piece 46 is secured to the upper portion of the housing 22; however, attachment to the lower portion of the housing 24 is contemplated, depending on the application. Advantageously, the decorative piece 46 is secured to the housing portion 22, 24 without the use of threaded fasteners. More specifically, the decorative piece 46 is provided with a plurality of hook projections 122 (Figures 2, 16, 17, and 21) extending within a cutter interior 10, which are press-fitted into a separate retainer 124 positioned on a lower portion 126 (Figure 2) of the housing portion 22, 24 receiving the decorative piece. As described above, the housing portion 22, 24 is of 7.R} bnn / P7n7 / B / YIAI preference metal, such as aluminum or the like, and decorative piece 46 and retainer 124 are both preferably made of plastic, decorative piece 46 preferably covered with metal or aluminum as known in the art. During assembly, the decorative piece 46 and the retainer 124 are secured to each other with the respective housing portion 22, 24 sandwiched between them. The retainer 124 is provided with a complementary plurality of retaining projections 128, 130, constructed and positioned to engage the hook projections 122. The plurality of retainer projections includes a first plurality of flat projections 128 and a second plurality of dogleg projections 130, the latter configured to exert a preloaded clamping force on the hook projections 122 (Figure 20). Furthermore, the projections 130 exert a clamping or pulling force against the decorative piece 46, holding it in close relation to the housing portion 22, 24. The flat projections 128 are received in grooves 132 in the decorative piece 46. Now, with reference to Figures 8, 16, and 17, the chassis 12 is further provided with at least one projection recess 134 to accommodate the hook projections 122 and the retention projections 128, 130 in a more secure location on the housing portions 22, 24 within the chassis. In addition, the upper and lower housing portions 22, 24 are provided with at least one mounting protrusion 136 configured to project through the complementary holes 138 in the chassis, such that fasteners pass through the holes and securely retain the chassis between the upper and lower housing portions. } frnn / eznz / e / YiAi Now, with reference to Figure 16, at least one of the housing portions 22, 24 includes at least one locating formation 140 projecting from an interior of the housing portion and coincidentally engaging at least one complementary receiving formation 142 on the chassis. These formations 140 facilitate the placement of the housing portions 22, 24 on the chassis 12 during the assembly of the hair clipper 10. Now, with reference to Figures 13 and 14, another feature of the present hair clipper 10 is that the cam follower 110 is slidably retained within the central opening 112 of the assembly 104 for lateral reciprocating motion. Furthermore, when the user chooses to remove the blade assembly 26 for maintenance, the engagement of the cam follower 110 in the assembly 104 retains the cam follower in the operational position, so the user does not risk losing the component during disassembly of the clipper. More specifically, at an upper end 144 of the cam follower 110, a crossbar 146 is slidably engaged and laterally moves in the travel path 108. The forked or bifurcated ends 148 of the crossbar 146 exert a friction fit within the travel path 108 and help retain the cam follower 110 in position. Moving toward the rear end 40, a generally U-shaped mount 150 is defined behind the crossbar 146. A tongue 152, generally projecting vertically, defines a rear end of the mount. 150. Mounting 150 is dimensioned to desirably engage with an upper beam 154 of the assembly 104 when the cam follower is operationally engaged at one end of the drive arm 111. The tongue 152 is received in an opening 156 in the beam 154. In addition, a front face 158 of the cam follower includes a projection 160 that engages in a groove (not shown) in the movable blade 30. During operation of the hair clipper 10, the rotating drive arm 111 causes lateral movement of the cam follower 110, which, through engagement of the projection 160, causes lateral movement of the movable blade 30 relative to the stationary blade 28, causing the cutting action. When periodic maintenance of the blade set 26 is required, the user can easily separate the blades 28, 30, leaving the U-shaped sliding support 106 in place. The cam follower 110 is held in place in the opening 112 by the coupling of the mount 150 on the upper beam 154 and the presence of the support 106. One method for assembling the hair clipper 10 includes providing the chassis 12 having upper and lower chassis portions 14, 16 defining an enclosed inner chamber 18, the upper and lower chassis portions configured to be secured together, providing the outer casing 20 including upper and lower casing portions 22, 24 constructed and positioned to enclose the chassis as the casing portions are secured together so that the inner chamber is isolated from the casing; providing the chassis 12 with the first blade end 38 and the second rear end 40 and the blade end including an integral blade guide channel 102.The blade guide channel 102 is incorporated into a formation 104 that defines a surface} frnn / eznz / e / YiAi that receives the housing 114 oriented at an oblique angle α for an angle defined by the chassis, and the lower portion of the housing has an angled front edge 116 that slides along the surface receiving the housing. The upper and lower portions of the housing 22, 24 are secured together such that they enclose the chassis 12. While a particular embodiment of the present multi-piece hair clipper construction with a metal housing has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects and as set forth in the following claims.

Claims

1. A hair clipper, comprising: a chassis (12) having upper and lower chassis portions (14, 16) defining a closed inner chamber (18), said upper and lower chassis portions configured to be secured together, and an outer casing (20) including upper and lower casing portions (22, 24) constructed and positioned to enclose said chassis as said casing portions are secured together so that said inner chamber is isolated from said casing.

2. The hair clipper according to claim 1, wherein said chassis (12) is made of electrically insulating material and said outer casing (20) is made of metal.

3. The hair clipper according to claim 1, wherein said inner chamber (18) includes a motor recess (48).

4. The hair clipper according to claim 3 further includes a motor (50) held in said motor recess (48) by close cooperation of the complementary formations in said upper and lower portions (14, 16) of the chassis. 7.R} πηη / ρζηζ / Β / γίΛΐ 5. The hair clipper according to claim 4, wherein said complementary formations include crushing ribs (56) in one of said chassis portions, and dependent wedges (52) in the other of said chassis portions, said wedges being coupled into the cavities (64) in said crushing ribs.

6. The hair clipper according to claim 5, further comprising threaded fasteners used to secure said upper and lower chassis portions together also locating said motor (50) in said motor recess (48).

7. The hair clipper according to claim 1, further comprising robust grip formations (44) loosely connected to said chassis, and constructed and positioned to be compressed into the assembly of said upper and lower portions (22, 24) of the housing 8. The hair clipper according to claim 7, wherein said sturdy handles (44) are connected to said chassis by a hook and loop connection system.

9. The hair clipper according to claim 8, wherein said hook and loop connection system includes at least one ramp hook (82) on said chassis and at least one complementary loop (78) on said handle, each said hook being surrounded by a rest (84) that receives said hook.} frnn / eznz / e / YiAi 10. The hair clipper according to claim 9, wherein said handle (44) has at least one said loop (78) projecting from an upper edge, and at least one said loop projecting from a lower edge.

11. The hair clipper according to claim 9, wherein each said handle (44) includes at least one supplementary clamping formation (88) at at least one of a front end and a rear end and said chassis is configured to receive at least said supplementary clamping formation in a press-fit coupling.

12. The hair clipper according to claim 1, wherein said chassis (12) has a first blade end (38) and a second rear end (40) and said blade end includes an integral blade guide channel (102).

13. The hair clipper according to claim 12, wherein said blade guide channel (102) is incorporated into a formation (104) that defines a travel path (108) for a cam follower (110).

14. The hair clipper according to claim 12, wherein said blade guide channel (102) is incorporated in a formation defining a surface receiving the housing oriented at an oblique angle to an axis defined by said chassis to slideably receive an angled front edge (116) of one of said upper and lower portions of the housing.

15. The hair clipper according to claim 13, wherein said cam follower (110) includes a mount (150) for slidingly coupling an upper beam (150) of said formation (104), said coupling of said mount in said formation retaining said cam follower (110) in said formation during the periodic removal of a set of clipper blades (26) attached to said chassis.

16. The hair clipper according to claim 15, wherein said mount (150) is defined by a crossbar slidably coupled to said travel path and a tongue generally projecting vertically (152).

17. The hair clipper according to claim 1, further comprising at least one decorative piece (46) attached to one of said upper and lower portions (22, 24) of the housing without the use of threaded fasteners.

18. The hair clipper according to claim 17, wherein said decorative piece (46) is provided with a plurality of hook projections (122) extending into an interior of said clipper, which are press-fitted into a separate retainer (124) positioned in a lower portion (126) of said housing portion receiving said decorative piece.

19. The hair clipper according to claim 18, wherein said retainer (124) is provided with a complementary plurality of retaining projections (128) constructed and positioned to engage said hook projections (122).} frnn / eznz / e / YiAi 20. The hair clipper according to claim 19, wherein said plurality of retaining projections (128) include a first plurality of flat projections and a second plurality of dog paw projections (130), the latter configured to exert a preloaded clamping force on said hook projections.

21. The hair clipper according to claim 1, wherein said upper and lower portions (22, 24) of the housing are provided with mounting protrusions (136) configured to project through complementary holes (138) in said chassis, such that fasteners pass through said holes and firmly retain said chassis between said upper and lower portions of the housing.

22. The hair clipper according to claim 21, wherein at least one of said housing portions (22, 24) includes at least one locating formation (140) projecting from an interior of said housing portion, and coincidentally engaging at least one complementary receiving formation (142) in said chassis.

23. A method for assembling a hair clipper, comprising: providing a chassis having upper and lower chassis portions defining an enclosed inner chamber, said upper and lower chassis portions configured to be secured together; providing an outer casing including upper and lower casing portions constructed and positioned to enclose said chassis as said casing portions are secured together so that said inner chamber is isolated from said casing; providing said chassis with a first blade end and a second rear end, said blade end including an integral blade guide channel;said blade guide channel is incorporated into a formation that defines a surface receiving the housing oriented at an oblique angle to an angle defined by said chassis and 10 said lower portion of the housing has an angled front edge that slides along said surface receiving the housing.;

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