Patent Application
20080098534
1. Field of the Invention
This invention relates to a tape dispenser, particularly to one having a telescopic knife in its grip, able to be forced elastically by a torsion spring to retreat back into the grip while not using.
2. Description of the Prior Art
As shown in
The objective of this invention is to offer a tape dispenser with a grip having a safety telescopic knife.
The main characteristics of the grip in the invention are a right semi-shell and a left semi-shell that are combined together tightly. The right semi-shell includes a rectangular pushing recess concaved longitudinally at a location of its outer side. The pushing recess is provided with a pushing hole for assembling a telescopic knife set, which consists of a knife set, a cutting blade and a connecting board. There are two projections located in the lower portion of the outer side of the knife set for fitting the cutting blade. The connecting board covered on the inner side of the knife set is provided with a restricting slot set at the bottom of its outer side for fitting a lower portion of a projecting longitudinal rib set on the inner side of the knife set so as to keep the knife set restricted. The projecting rib is provided with a ditch dug longitudinally in its upper portion for fitting a torsion spring therein. In addition, a pushing knob provided with a pushing surface is installed in the pushing recess and connected with the knife set by a screw screwing in a screw hole in the knife set. When the pushing surface is pressed, the cutting blade is to be pushed to extend out. As the pushing force against the pushing surface diminishes, the knife set is to be forced elastically by the torsion spring to draw back the cutting blade into the grip without being exposed nakedly, able to prevent it from damaged or hurting people.
This invention is better understood by referring to the accompanying drawings, wherein:
As shown in
The grip 20 consists of a right semi-shell 21 and a left semi-shell 22 combined tightly with the right semi-shell 21 together. The right semi-shell 21 is provided with a rectangular pushing recess 23 concaved longitudinally at a preset location of its outer side. The pushing recess 23 has a V-shaped groove 231 extended from its bottom, a projecting rim 232 respectively protruded inwards at two ends of the V-shaped groove 231 connecting with the pushing recess 23, and a pushing hole 233 opened longitudinally. The right semi-shell 21 is additionally provided with plural projecting bars 24 projected around the circumference of its internal wall to be spaced from its edge properly, a spring base 25 set at a preset position located in the center of its right side and abutting to one of the projecting bars 24, and an opening 211 bored at a preset position in the bottom of its exterior side. The spring base 25 is provided with a restricting small projection 251 protruding on its top and a guiding groove 252 concaved in its bottom portion.
The telescopic knife set 30 installed inside the right semi-shell 21 consists of a knife base 31, a cutting blade 32 and a connecting board 33. The knife base 31 includes a pushing head 311 projecting on the top end of its outer side for sliding in the pushing hole 233 to move up and down longitudinally, and two projections 312 set at its lower portion and spaced apart properly for fitting the cutting blade 32. The cutting blade 32 having two hook-shaped blades 321 at its two ends is able to pass through the opening 211 of the right semi-shell 21 to uncover itself for cutting. In addition, the knife base 31 is provided with a projecting longitudinal rib 313 located on its inner side and a ditch 314 dug horizontally in the upper portion of the projecting longitudinal rib 313. The connecting board 33 covered on the inner side of the knife base 31 is provided with a restricting slot 331 defined by two spaced-apart blocks set in the bottom of its outer side for locking with the projecting longitudinal rib 313 of the knife base 31, enabling the knife base 31 restricted immovably while driving the cutting blade 32 to extend out. There are also plural fitting ears 332 provided in the connecting board 33, which are positioned around the circumference of the connecting board 33 and spaced apart properly to correspond to the projecting bars 24 of the right semi-shell 21. Each of the fitting ears 332 has a fitting hole 333 for fitting steadily with the projecting bar 24 so as to keep the knife base 31 fixed inside the right semi-shell 21.
The pushing knob 40, shaped equivalent to the pushing recess 23 and fitted in it, is provided with a locking element 41, a screw hole 42 and a V-shaped cone 43 located at its bottom end to correspond with V-shaped groove 231. The locking element 41 is to pass through the screw hole 42 and the pushing hole 233 of the pushing recess 23 to screw in the pushing block 311 of the knife base 31. The locking element 41 is a screw. The V-shaped cone 43 has a push surface 431 formed on an upper surface, for a user to push the pushing knob 40 to move up and down along the pushing hole 233. In addition, the V-shaped cone 43 of the pushing knob 40 can be moved down in the pushing hole 233 to interlock with the projecting rims 232 of the pushing recess 23.
The torsion spring 50 pivotally fixed with the restricting bar 251 of the spring base 25 of the right semi-shell 21 is fitted in the ditch 314 of the knife base 31 with its one end restricted in the guiding groove 252 with the other end, so that the knife base 31 can be pushed back elastically by the torsion spring 50 to keep the cutting blade 32 retracted in the right semi-shell 21 after being moved in the pushing hole 233.
In using, as shown in
The invention has the following advantages as can be seen from the foresaid description.
1. The telescopic knife set 30 is to be automatically pushed back into the handle 20 by the elasticity of the torsion spring 50 while not being used, prevented from causing hurt and used with safety.
2. The V-shaped cone 43 of the pushing knob 40 can be fitted with the V-shaped groove 231 and locked by the projecting rims 232 to keep the pushing knob 40 positioned immovably for cutting job. The locking surface of the V-shaped cone 43 is so small that the cutting blade 32 can be forced back into the handle 20 quickly by the torsion spring 50. And, the pushing surface 431 of the pushing knob 40 makes the invention easy for a user to operate.
3. By means of the locking element 41 screwed to tighten the pushing knob 40 with the knife base 31, it provides a stable assembly. And, the connecting board 33 used to keep the telescopic knife set 30 fixed in the right semi-shell 21 can keep the knife base 31 positioned restrictively by the restricting slot 331 while driving the cutting blade 32 to extend out, guaranteeing a steady operation.
4. The edge of the cutting blade 32 can be formed with different shapes to meet various requirements, able to widen its application.
While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.
