CA2121663C - Blackboard - Google Patents
BlackboardInfo
- Publication number
- CA2121663C CA2121663C CA002121663A CA2121663A CA2121663C CA 2121663 C CA2121663 C CA 2121663C CA 002121663 A CA002121663 A CA 002121663A CA 2121663 A CA2121663 A CA 2121663A CA 2121663 C CA2121663 C CA 2121663C
- Authority
- CA
- Canada
- Prior art keywords
- flange
- tray
- blackboard
- longitudinally extending
- front side
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
- B43L—ARTICLES FOR WRITING OR DRAWING UPON; WRITING OR DRAWING AIDS; ACCESSORIES FOR WRITING OR DRAWING
- B43L1/00—Repeatedly-usable boards or tablets for writing or drawing
- B43L1/04—Blackboards
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
- B43L—ARTICLES FOR WRITING OR DRAWING UPON; WRITING OR DRAWING AIDS; ACCESSORIES FOR WRITING OR DRAWING
- B43L19/00—Erasers, rubbers, or erasing devices; Holders therefor
Landscapes
- Drawing Aids And Blackboards (AREA)
Abstract
A blackboard includes a rectangular board member, a protective frame member provided on each side of the board member, and a tray connected to a lowermost one of the frame members and movable between an unfolded position for receiving erasers and writing implements and a folded position. The lowermost one of the frame members has a front side which is formed with a longitudinally extending retaining portion that confines a longitudinally extending space which is substantially L-shaped in cross-section. The tray has a rear side wall which is formed with a transversely and longitudinally extending rearward anchor projection that is substantially T-shaped in cross-section and that has a head portion which extends into the space.
Description
.- .
BLACKBOARD
FIELD OF THE INVENTION
The invention relates to a blackboard, more particularly to a blackboard with a foldable tray.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate an embodiment of the inventlon, Figure 1 is a perspective view of a first example of a conventional blackboard;
10Figure 2 is a II - II section of the conventional blackboard shown in Figure 1;
Figure 3 is an illustration of a second example of a conventional blackboard;
Figure 4 is an illustration of a third example of a conventional blackboard;
Figure 5 is a perspective view of the preferred embodiment of a blackboard according to the present invention;
Figure 6 is a VI - VI section of the preferred embodiment as shown in Figure 5; and Figure 7 is an illustration of the preferred embodiment when a tray thereof is folded.
BACKGROUND OF THE INVENTION
Referring to Figure 1, a conventional blackboard 1 is shown to comprise a rectangular board member 10 and a protective frame member 11 disposed on each side of the board member 10. A tray 12 is formed on a lowermost one of the frame members 11 and is used to receive erasers and writing implements. The conventional blackboard 1 requires a relatively large packaging volume because of the width of the tray 12, as shown in Figure 2. The transport and packaging costs of the conventional blackboard 1 are thus relatively high.
Figure 3 is an illustration of a second example of a conventional blackboard 2. The tray 13 is separate from the lowermost frame member 14, thereby reducing the packaging volume of the conventional blackboard 2. A
catch 15 is provided on the rear side of the frame member 14 and is used to join the tray 13 and the frame member 14 when the conventional blackboard 2 is in use.
The blackboard 2 is inconvenient to use because of the need to assemble the tray 13 on the frame member 14.
A third example of a conventional blackboard 3 is shown in Figure 4. The blackboard 3 has a lowermost frame member 21 which has a front side that is formed with a longitudinally extending retaining portion that defines a longitudinally extending rounded groove 211.
The blackboard 3 further has a tray 22 which has a rear side that is provided with a longitudinally extending cylindrical lug 221 which is rotatably received in the groove 211. The lug 221 permits upward rotation of the tray 22 from an unfolded position, wherein the tray 22 is supported by the retaining portion so as to receive writing implements and the like, to a folded position.
-The tray 22 is folded so as to reduce the packaging volume of the blackboard 3, thereby reducing the transport and packaging costs of the blackboard 3.
Some of the drawbacks of the conventional blackboard 3 are as follows:
1. The material cost of the blackboard 3 is relatively high. Note that the lowermost frame member 21 is usually made of aluminum. The groove-and-lug connection between the frame member 21 and the tray 22 requires more raw material and yields more scrap.
BLACKBOARD
FIELD OF THE INVENTION
The invention relates to a blackboard, more particularly to a blackboard with a foldable tray.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate an embodiment of the inventlon, Figure 1 is a perspective view of a first example of a conventional blackboard;
10Figure 2 is a II - II section of the conventional blackboard shown in Figure 1;
Figure 3 is an illustration of a second example of a conventional blackboard;
Figure 4 is an illustration of a third example of a conventional blackboard;
Figure 5 is a perspective view of the preferred embodiment of a blackboard according to the present invention;
Figure 6 is a VI - VI section of the preferred embodiment as shown in Figure 5; and Figure 7 is an illustration of the preferred embodiment when a tray thereof is folded.
BACKGROUND OF THE INVENTION
Referring to Figure 1, a conventional blackboard 1 is shown to comprise a rectangular board member 10 and a protective frame member 11 disposed on each side of the board member 10. A tray 12 is formed on a lowermost one of the frame members 11 and is used to receive erasers and writing implements. The conventional blackboard 1 requires a relatively large packaging volume because of the width of the tray 12, as shown in Figure 2. The transport and packaging costs of the conventional blackboard 1 are thus relatively high.
Figure 3 is an illustration of a second example of a conventional blackboard 2. The tray 13 is separate from the lowermost frame member 14, thereby reducing the packaging volume of the conventional blackboard 2. A
catch 15 is provided on the rear side of the frame member 14 and is used to join the tray 13 and the frame member 14 when the conventional blackboard 2 is in use.
The blackboard 2 is inconvenient to use because of the need to assemble the tray 13 on the frame member 14.
A third example of a conventional blackboard 3 is shown in Figure 4. The blackboard 3 has a lowermost frame member 21 which has a front side that is formed with a longitudinally extending retaining portion that defines a longitudinally extending rounded groove 211.
The blackboard 3 further has a tray 22 which has a rear side that is provided with a longitudinally extending cylindrical lug 221 which is rotatably received in the groove 211. The lug 221 permits upward rotation of the tray 22 from an unfolded position, wherein the tray 22 is supported by the retaining portion so as to receive writing implements and the like, to a folded position.
-The tray 22 is folded so as to reduce the packaging volume of the blackboard 3, thereby reducing the transport and packaging costs of the blackboard 3.
Some of the drawbacks of the conventional blackboard 3 are as follows:
1. The material cost of the blackboard 3 is relatively high. Note that the lowermost frame member 21 is usually made of aluminum. The groove-and-lug connection between the frame member 21 and the tray 22 requires more raw material and yields more scrap.
2. Note that the tray 22 contacts the frame member 21 at lines A, B on the retaining portion of the latter whenever the tray 22 is folded or unfolded. Since aluminum is a relatively soft material, scars are formed at the lines A, B on the tray 22 after repeated folding and unfolding movement of the tray 22, thereby diminishing the aesthetic appeal of the blackboard 3.
SUMMARY OF THE INVENTION
Therefore, the main objective of the present invention is to provide a blackboard with a foldable tray which permits a reduction in the packaging volume in order to reduce the transport and packaging costs of the blackboard and which utilizes less raw material in order to reduce the material cost of the blackboard.
Another objective of the present invention is to provide a blackboard with a foldable tray which minimizes the formation of scar lines on the tray even after repeated folding and unfolding movement of the tray.
Accordingly, a blackboard of the present invention includes a rectangular board member, a protective frame member provided on each side of the board member, and a tray connected to a lowermost one of the frame members and movable between an unfolded position for receiving erasers and writing implements and a folded position.
The lowermost one of the frame members has a front side which is formed with a longitudinally extending retaining portion that includes a first flange extending frontwardly from the front side, a second flange similarly extending frontwardly from the front side below the first flange and being longer than the first flange, a third flange extending downwardly from a distal end of the first flange, a fourth flange extending upwardly from a distal end of the second flange, and a fifth flange extending rearwardly from a distal end of the fourth flange. The retaining portion confines a longitudinally extending space which is substantially L-shaped in cross-section and which is accessible via an opening that is defined by the distal ends of the third and fifth flanges.
The tray has a rear side wall which is formed with a transversely and longitudinally extending rearward anchor projection that is substantially T-shaped in cross-section and that has a head portion which extends -into the space via the opening.
The rear side wall abuts against the fourth flange, the anchor projection is supported by the fifth flange, and the head portion is retained between the front side of the frame member and the third flange when the tray is in the unfolded position.
The anchor projection abuts against the third flange, and the head portion is retained between the second and fifth flanges when the tray is in the folded pOSltlon.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figures 5 and 6, the preferred embodiment of a blackboard according to the present invention is shown to comprise a rectangular board member 30 which may be a white board or a black board, a protective frame member 40 disposed on each side of the board member 30, and an elongated tray 50 extending from a lowermost one of the frame members 40 and used to receive erasers and writing implements.
The lowermost frame member 40 has a front side which is formed with a longitudinally extending retaining portion 41. The retaining portion 41 includes a first flange 410 which extends frontwardly from the front side of the lowermost frame member 40 and a second flange 411 which similarly extends frontwardly from the front side of the lowermost frame member 40 below the first flange 410. A third flange 412 extends downwardly -from a distal end of the first flange 410. The second flange 411 is longer than the first flange 410. A
fourth flange 413 extends upwardly from a distal end of the second flange 411. A fifth flange 415 extends rearwardly from a distal end of the fourth flange 413.
The retaining portion 41 confines a longitudinally extending space 42 which is substantially L-shaped in cross-section and which is accessible via an opening that is defined by the distal ends of the third and fifth flanges 412, 415.
The tray 50 has a rear side wall 502 which is formed with a transversely and longitudinally extending rearward anchor projection 504 that extends into the space 42 and that is substantially T-shaped in cross-section.
When the tray 50 is in an unfolded position, the rear side wall 502 abuts against the fourth flange 413 of the retaining portion 41, as shown in Figure 6. The anchor projection 504 is supported by the fifth flange 415 and has a head portion 5041 which is retained between the front side of the lowermost frame member 40 and the third flange 412.
The tray 50 is rotated upwardly so as to place the tray 50 in the folded position, as shown in Figure 7.
When the tray 50 is in the folded position, the anchor projection 504 abuts against the third flange 412. The head portion 5041 of the anchor projection 504 is 21216~:~
-retained between the second and fifth flanges 411, 415.
It has thus been shown that the head portion 5041 of the anchor projection 504 is retained in the space 42 regardless of the direction of the movement of the tray 50.
The advantages and characterizing features of the blackboard of the present invention are as follows:
1. The tray is foldable, and thus, the packaging volume of the blackboard can be reduced so as to lower the packaging and transport costs of the same.
2. Friction between the head portion 5041 and the retaining portion 41 on the lowermost frame member 40 is relatively small since the contact area therebetween is less than that between the rounded groove 211 and the cylindrical lug 221 of the conventional blackboard 3 shown in Figure 4. Movement of the tray 50 between the folded and unfolded positions can be easily accomplished without decreasing the load bearing capacity of the tray 50.
3. The material cost of the preferred embodiment is lower because the anchor projection 504 requires less raw material.
SUMMARY OF THE INVENTION
Therefore, the main objective of the present invention is to provide a blackboard with a foldable tray which permits a reduction in the packaging volume in order to reduce the transport and packaging costs of the blackboard and which utilizes less raw material in order to reduce the material cost of the blackboard.
Another objective of the present invention is to provide a blackboard with a foldable tray which minimizes the formation of scar lines on the tray even after repeated folding and unfolding movement of the tray.
Accordingly, a blackboard of the present invention includes a rectangular board member, a protective frame member provided on each side of the board member, and a tray connected to a lowermost one of the frame members and movable between an unfolded position for receiving erasers and writing implements and a folded position.
The lowermost one of the frame members has a front side which is formed with a longitudinally extending retaining portion that includes a first flange extending frontwardly from the front side, a second flange similarly extending frontwardly from the front side below the first flange and being longer than the first flange, a third flange extending downwardly from a distal end of the first flange, a fourth flange extending upwardly from a distal end of the second flange, and a fifth flange extending rearwardly from a distal end of the fourth flange. The retaining portion confines a longitudinally extending space which is substantially L-shaped in cross-section and which is accessible via an opening that is defined by the distal ends of the third and fifth flanges.
The tray has a rear side wall which is formed with a transversely and longitudinally extending rearward anchor projection that is substantially T-shaped in cross-section and that has a head portion which extends -into the space via the opening.
The rear side wall abuts against the fourth flange, the anchor projection is supported by the fifth flange, and the head portion is retained between the front side of the frame member and the third flange when the tray is in the unfolded position.
The anchor projection abuts against the third flange, and the head portion is retained between the second and fifth flanges when the tray is in the folded pOSltlon.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figures 5 and 6, the preferred embodiment of a blackboard according to the present invention is shown to comprise a rectangular board member 30 which may be a white board or a black board, a protective frame member 40 disposed on each side of the board member 30, and an elongated tray 50 extending from a lowermost one of the frame members 40 and used to receive erasers and writing implements.
The lowermost frame member 40 has a front side which is formed with a longitudinally extending retaining portion 41. The retaining portion 41 includes a first flange 410 which extends frontwardly from the front side of the lowermost frame member 40 and a second flange 411 which similarly extends frontwardly from the front side of the lowermost frame member 40 below the first flange 410. A third flange 412 extends downwardly -from a distal end of the first flange 410. The second flange 411 is longer than the first flange 410. A
fourth flange 413 extends upwardly from a distal end of the second flange 411. A fifth flange 415 extends rearwardly from a distal end of the fourth flange 413.
The retaining portion 41 confines a longitudinally extending space 42 which is substantially L-shaped in cross-section and which is accessible via an opening that is defined by the distal ends of the third and fifth flanges 412, 415.
The tray 50 has a rear side wall 502 which is formed with a transversely and longitudinally extending rearward anchor projection 504 that extends into the space 42 and that is substantially T-shaped in cross-section.
When the tray 50 is in an unfolded position, the rear side wall 502 abuts against the fourth flange 413 of the retaining portion 41, as shown in Figure 6. The anchor projection 504 is supported by the fifth flange 415 and has a head portion 5041 which is retained between the front side of the lowermost frame member 40 and the third flange 412.
The tray 50 is rotated upwardly so as to place the tray 50 in the folded position, as shown in Figure 7.
When the tray 50 is in the folded position, the anchor projection 504 abuts against the third flange 412. The head portion 5041 of the anchor projection 504 is 21216~:~
-retained between the second and fifth flanges 411, 415.
It has thus been shown that the head portion 5041 of the anchor projection 504 is retained in the space 42 regardless of the direction of the movement of the tray 50.
The advantages and characterizing features of the blackboard of the present invention are as follows:
1. The tray is foldable, and thus, the packaging volume of the blackboard can be reduced so as to lower the packaging and transport costs of the same.
2. Friction between the head portion 5041 and the retaining portion 41 on the lowermost frame member 40 is relatively small since the contact area therebetween is less than that between the rounded groove 211 and the cylindrical lug 221 of the conventional blackboard 3 shown in Figure 4. Movement of the tray 50 between the folded and unfolded positions can be easily accomplished without decreasing the load bearing capacity of the tray 50.
3. The material cost of the preferred embodiment is lower because the anchor projection 504 requires less raw material.
4. Little or no scar lines are formed on the tray 50 after repeated folding and unfolding movement of the tray 50, While the present invention has been described in connection with what is considered the most practical " 2121663 -and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Claims
1. A blackboard including a rectangular board member, a protective frame member provided on each side of the board member, and a tray connected to a lowermost one of said frame members and movable between an unfolded position for receiving erasers and writing implements and a folded position, characterized by:
said lowermost one of said frame members having a front side which is formed with a longitudinally extending retaining portion that includes a first flange extending frontwardly from said front side, a second flange similarly extending frontwardly from said front side below said first flange and being longer than said first flange, a third flange extending downwardly from a distal end of said first flange, a fourth flange extending upwardly from a distal end of said second flange, and a fifth flange extending rearwardly from a distal end of said fourth flange;
said retaining portion confining a longitudinally extending space which is substantially L-shaped in cross-section and which is accessible via an opening that is defined by the distal ends of said third and fifth flanges;
said tray having a rear side wall which is formed with a transversely and longitudinally extending rearward anchor projection that is substantially T-shaped in cross-section and that has a head portion which extends into said space via said opening;
said rear side wall abutting against said fourth flange, said anchor projection being supported by said fifth flange, and said head portion being retained between said front side and said third flange when said tray is in the unfolded position; and said anchor projection abutting against said third flange, and said head portion being retained between said second and fifth flanges when said tray is in the folded position.
said lowermost one of said frame members having a front side which is formed with a longitudinally extending retaining portion that includes a first flange extending frontwardly from said front side, a second flange similarly extending frontwardly from said front side below said first flange and being longer than said first flange, a third flange extending downwardly from a distal end of said first flange, a fourth flange extending upwardly from a distal end of said second flange, and a fifth flange extending rearwardly from a distal end of said fourth flange;
said retaining portion confining a longitudinally extending space which is substantially L-shaped in cross-section and which is accessible via an opening that is defined by the distal ends of said third and fifth flanges;
said tray having a rear side wall which is formed with a transversely and longitudinally extending rearward anchor projection that is substantially T-shaped in cross-section and that has a head portion which extends into said space via said opening;
said rear side wall abutting against said fourth flange, said anchor projection being supported by said fifth flange, and said head portion being retained between said front side and said third flange when said tray is in the unfolded position; and said anchor projection abutting against said third flange, and said head portion being retained between said second and fifth flanges when said tray is in the folded position.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002121663A CA2121663C (en) | 1994-04-19 | 1994-04-19 | Blackboard |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002121663A CA2121663C (en) | 1994-04-19 | 1994-04-19 | Blackboard |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2121663A1 CA2121663A1 (en) | 1995-10-20 |
| CA2121663C true CA2121663C (en) | 1997-11-04 |
Family
ID=4153409
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002121663A Expired - Fee Related CA2121663C (en) | 1994-04-19 | 1994-04-19 | Blackboard |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2121663C (en) |
-
1994
- 1994-04-19 CA CA002121663A patent/CA2121663C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2121663A1 (en) | 1995-10-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |